Subjects -> ENVIRONMENTAL STUDIES (Total: 913 journals)
    - ENVIRONMENTAL STUDIES (810 journals)
    - POLLUTION (31 journals)
    - WASTE MANAGEMENT (18 journals)

ENVIRONMENTAL STUDIES (810 journals)            First | 1 2 3 4 5     

Showing 401 - 378 of 378 Journals sorted alphabetically
International Journal of Environment and Pollution     Hybrid Journal   (Followers: 3)
International Journal of Environment and Sustainable Development     Hybrid Journal   (Followers: 17)
International Journal of Environment and Waste Management     Hybrid Journal   (Followers: 2)
International Journal of Environment, Workplace and Employment     Hybrid Journal   (Followers: 7)
International Journal of Environmental Engineering     Hybrid Journal   (Followers: 6)
International Journal of Environmental Health Engineering     Open Access   (Followers: 1)
International Journal of Environmental Health Research     Hybrid Journal   (Followers: 3)
International Journal of Environmental Policy and Decision Making     Hybrid Journal   (Followers: 3)
International Journal of Environmental Research     Hybrid Journal  
International Journal of Environmental Research and Public Health     Open Access   (Followers: 22)
International Journal of Environmental Science and Technology     Hybrid Journal   (Followers: 6)
International Journal of Environmental Studies     Hybrid Journal   (Followers: 5)
International Journal of Exergy     Hybrid Journal   (Followers: 2)
International Journal of Global Environmental Issues     Hybrid Journal   (Followers: 4)
International Journal of Global Sustainability     Open Access   (Followers: 2)
International Journal of Global Warming     Hybrid Journal  
International Journal of Greenhouse Gas Control     Partially Free   (Followers: 5)
International Journal of Hygiene and Environmental Health     Hybrid Journal   (Followers: 7)
International Journal of Logistics Research and Applications : A Leading Journal of Supply Chain Management     Hybrid Journal   (Followers: 16)
International Journal of Mining and Geo-Engineering     Open Access  
International Journal of Phytoremediation     Hybrid Journal   (Followers: 1)
International Journal of Process Systems Engineering     Hybrid Journal   (Followers: 1)
International Journal of Recycling of Organic Waste in Agriculture     Open Access   (Followers: 1)
International Journal of Reliability and Safety     Hybrid Journal   (Followers: 11)
International Journal of Renewable Energy Development     Open Access   (Followers: 6)
International Journal of Social Sciences and Management     Open Access   (Followers: 2)
International Journal of Soil, Sediment and Water     Open Access   (Followers: 4)
International Journal of Stress Management     Full-text available via subscription   (Followers: 6)
International Journal of Sustainable Construction Engineering and Technology     Open Access   (Followers: 7)
International Journal of Sustainable Engineering     Hybrid Journal   (Followers: 4)
International Journal of Sustainable Materials and Structural Systems     Hybrid Journal   (Followers: 1)
International Journal of Sustainable Society     Hybrid Journal   (Followers: 2)
International Journal of the Commons     Open Access   (Followers: 2)
International Journal of Toxicology     Hybrid Journal   (Followers: 17)
International Journal of Water Resources and Environmental Engineering     Open Access   (Followers: 12)
International Review of Environmental and Resource Economics     Full-text available via subscription   (Followers: 4)
Iranian Journal of Health and Environment     Open Access  
ISLE: Interdisciplinary Studies in Literature and Environment     Hybrid Journal   (Followers: 3)
Isotopes in Environmental and Health Studies     Hybrid Journal  
JACEE (Journal of Advanced Civil and Environmental Engineering)     Open Access  
Jahangirnagar University Environmental Bulletin     Open Access  
Journal for the History of Environment and Society     Open Access   (Followers: 3)
Journal of Bioremediation & Biodegradation     Open Access   (Followers: 1)
Journal of Earth Science & Climatic Change     Open Access   (Followers: 14)
Journal of Petroleum & Environmental Biotechnology     Open Access   (Followers: 1)
Journal of Advances in Environmental Health Research     Open Access   (Followers: 2)
Journal Of Advances In Natural Sciences     Open Access   (Followers: 1)
Journal of Aging and Environment     Hybrid Journal   (Followers: 4)
Journal of Agricultural and Environmental Ethics     Hybrid Journal   (Followers: 8)
Journal of Agricultural Chemistry and Environment     Open Access   (Followers: 3)
Journal of Agriculture and Ecology Research International     Open Access  
Journal of Air Pollution and Health (رتبه علمی- پژوهشی)     Open Access  
Journal of Anatolian Environmental and Animal Sciences     Open Access  
Journal of Applied Ecology     Hybrid Journal   (Followers: 211)
Journal of Applied Meteorology and Climatology     Hybrid Journal   (Followers: 42)
Journal of Applied Sciences and Environmental Management     Open Access   (Followers: 1)
Journal of Applied Toxicology     Hybrid Journal   (Followers: 19)
Journal of Applied Volcanology     Open Access   (Followers: 7)
Journal of Applied Water Engineering and Research     Hybrid Journal  
Journal of Arid Environments     Hybrid Journal   (Followers: 12)
Journal of Biochemical and Molecular Toxicology     Hybrid Journal   (Followers: 4)
Journal of Biosystems Engineering     Full-text available via subscription  
Journal of Chemical Ecology     Hybrid Journal   (Followers: 4)
Journal of Civil Engineering and Environmental Sciences     Open Access  
Journal of Climate     Hybrid Journal   (Followers: 56)
Journal of Climate Change and Health     Open Access   (Followers: 6)
Journal of Coastal Research     Hybrid Journal   (Followers: 31)
Journal of Contaminant Hydrology     Hybrid Journal   (Followers: 19)
Journal of Earth, Environment and Health Sciences     Open Access   (Followers: 2)
Journal of East African Natural History     Full-text available via subscription   (Followers: 7)
Journal of Ecology     Hybrid Journal   (Followers: 142)
Journal of Ecology and Environment     Open Access   (Followers: 3)
Journal of Economic Development, Environment and People     Open Access   (Followers: 11)
Journal of Energy & Natural Resources Law     Hybrid Journal   (Followers: 5)
Journal of Energy and Environment Technology of Graduate School Siam Technology College     Open Access  
Journal of Environment and Earth Science     Open Access   (Followers: 11)
Journal of Environment and Ecology     Open Access   (Followers: 10)
Journal of Environment Pollution and Human Health     Open Access   (Followers: 3)
Journal of Environmental Analysis and Progress     Open Access  
Journal of Environmental and Agricultural Studies     Open Access   (Followers: 1)
Journal of Environmental and Public Health     Open Access   (Followers: 16)
Journal of Environmental Assessment Policy and Management     Hybrid Journal   (Followers: 5)
Journal of Environmental Chemical Engineering     Hybrid Journal   (Followers: 5)
Journal of Environmental Economics and Policy     Partially Free   (Followers: 4)
Journal of Environmental Education     Hybrid Journal   (Followers: 7)
Journal of Environmental Engineering and Landscape Management     Open Access   (Followers: 8)
Journal of Environmental Engineering and Science     Hybrid Journal   (Followers: 2)
Journal of Environmental Extension     Full-text available via subscription  
Journal of Environmental Geography     Open Access   (Followers: 6)
Journal of Environmental Law     Hybrid Journal   (Followers: 22)
Journal of Environmental Management     Hybrid Journal   (Followers: 44)
Journal of Environmental Management     Open Access   (Followers: 1)
Journal of Environmental Management and Tourism     Open Access   (Followers: 13)
Journal of Environmental Media     Hybrid Journal  
Journal of Environmental Planning and Management     Hybrid Journal   (Followers: 26)
Journal of Environmental Policy & Planning     Hybrid Journal   (Followers: 14)
Journal of Environmental Professionals Sri Lanka     Open Access  
Journal of Environmental Protection     Open Access   (Followers: 1)
Journal of Environmental Science and Health, Part A: Toxic/Hazardous Substances and Environmental Engineering     Hybrid Journal   (Followers: 5)
Journal of Environmental Science and Health, Part B: Pesticides, Food Contaminants, and Agricultural Wastes     Hybrid Journal   (Followers: 5)
Journal of Environmental Science and Technology     Open Access   (Followers: 7)
Journal of Environmental Sciences     Full-text available via subscription   (Followers: 8)
Journal of Environmental Statistics     Open Access   (Followers: 4)
Journal of Environmental Studies and Sciences     Partially Free   (Followers: 2)
Journal of Environmental Sustainability     Open Access   (Followers: 7)
Journal of Environments     Open Access  
Journal of Exposure Science and Environmental Epidemiology     Hybrid Journal   (Followers: 6)
Journal of Fisheries and Environment     Open Access  
Journal of Forest and Natural Resource Management     Open Access  
Journal of Freshwater Ecology     Hybrid Journal   (Followers: 14)
Journal of Geography, Environment and Earth Science International     Open Access  
Journal of Geoscience and Environment Protection     Open Access  
Journal of Great Lakes Research     Hybrid Journal   (Followers: 5)
Journal of Green Building     Full-text available via subscription   (Followers: 10)
Journal of Hazardous Materials     Hybrid Journal   (Followers: 12)
Journal of Hazardous Materials Advances     Open Access  
Journal of Health Management     Hybrid Journal   (Followers: 10)
Journal of Health Organisation and Management     Hybrid Journal   (Followers: 29)
Journal of Housing and the Built Environment     Hybrid Journal   (Followers: 9)
Journal of Human Behavior in the Social Environment     Hybrid Journal   (Followers: 6)
Journal of Hydrology X     Open Access   (Followers: 5)
Journal of Industrial Ecology     Hybrid Journal   (Followers: 17)
Journal of Integrative Environmental Sciences     Hybrid Journal   (Followers: 4)
Journal of International Maritime Safety, Environmental Affairs, and Shipping     Open Access   (Followers: 1)
Journal of Iron and Steel Research International     Hybrid Journal   (Followers: 7)
Journal of Korean Society of Environmental Engineers     Open Access  
Journal of Land Use Science     Hybrid Journal   (Followers: 3)
Journal of Management and Sustainability     Open Access   (Followers: 7)
Journal of Mega Infrastructure & Sustainable Development     Hybrid Journal  
Journal of Natural Resources and Development     Open Access   (Followers: 2)
Journal of Natural Sciences Research     Open Access   (Followers: 1)
Journal of Occupational and Environmental Hygiene     Hybrid Journal   (Followers: 6)
Journal of Operational Oceanography     Hybrid Journal   (Followers: 5)
Journal of Organizational Behavior     Hybrid Journal   (Followers: 59)
Journal of Outdoor and Environmental Education     Hybrid Journal   (Followers: 2)
Journal of Pharmacological and Toxicological Methods     Hybrid Journal   (Followers: 7)
Journal of Plant Science and Phytopathology     Open Access  
Journal of Policy Analysis and Management     Hybrid Journal   (Followers: 28)
Journal of Population and Sustainability     Open Access  
Journal of Reliable Intelligent Environments     Hybrid Journal  
Journal of Renewable and Sustainable Energy     Hybrid Journal   (Followers: 11)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 5)
Journal of Rural and Community Development     Open Access   (Followers: 1)
Journal of Safety Engineering     Open Access   (Followers: 37)
Journal of Safety Research     Hybrid Journal   (Followers: 89)
Journal of School Violence     Hybrid Journal   (Followers: 6)
Journal of Sustainability and Environmental Management     Open Access   (Followers: 4)
Journal of Sustainable Development     Open Access   (Followers: 25)
Journal of Sustainable Development Studies     Open Access   (Followers: 15)
Journal of Sustainable Society     Open Access   (Followers: 2)
Journal of the American Planning Association     Hybrid Journal   (Followers: 18)
Journal of the Atmospheric Sciences     Hybrid Journal   (Followers: 83)
Journal of Tropical Ecology     Hybrid Journal   (Followers: 15)
Journal of Urban and Environmental Engineering     Open Access   (Followers: 5)
Journal of Urban Ecology     Open Access   (Followers: 5)
Journal of Vietnamese Environment     Open Access   (Followers: 1)
Journal of Water and Environmental Nanotechnology     Open Access   (Followers: 1)
Journal of Water Security     Open Access   (Followers: 6)
Julius-Kühn-Archiv     Open Access  
Jurnal Kesehatan Lingkungan     Open Access  
Jurnal Manusia dan Lingkungan     Open Access  
Jurnal Pengendalian Pencemaran Lingkungan     Open Access  
Jurnal Presipitasi     Open Access   (Followers: 1)
Jurnal Rekayasa Kimia & Lingkungan     Open Access  
Jurnal Sains & Teknologi Lingkungan     Open Access  
Jurnal Wilayah dan Lingkungan     Open Access  
Knowledge Management Research & Practice     Hybrid Journal   (Followers: 16)
Koedoe : African Protected Area Conservation and Science     Open Access   (Followers: 2)
Lake and Reservoir Management     Hybrid Journal   (Followers: 7)
Landscape Ecology     Hybrid Journal   (Followers: 61)
Landscapes     Hybrid Journal   (Followers: 18)
Latin American Journal of Management for Sustainable Development     Hybrid Journal  
Letras Verdes. Revista Latinoamericana de Estudios Socioambientales     Open Access  
Limnological Review     Open Access   (Followers: 3)
Living Reviews in Landscape Research     Open Access  
Local Environment: The International Journal of Justice and Sustainability     Hybrid Journal   (Followers: 8)
Low Carbon Economy     Open Access   (Followers: 4)
Luna Azul     Open Access  
M+A. Revista Electrónica de Medioambiente     Open Access  
Macquarie Journal of International and Comparative Environmental Law     Full-text available via subscription   (Followers: 7)
Madagascar Conservation & Development     Open Access   (Followers: 2)
Management International Review     Hybrid Journal   (Followers: 7)
Management of Environmental Quality: An International Journal     Hybrid Journal   (Followers: 2)
Management of Sustainable Development     Open Access   (Followers: 4)
Marine Ecology     Hybrid Journal   (Followers: 27)
Marine Ecology Progress Series MEPS     Hybrid Journal   (Followers: 34)
Marine Environmental Research     Hybrid Journal   (Followers: 31)
Marine Pollution Bulletin     Hybrid Journal   (Followers: 36)
Materials for Renewable and Sustainable Energy     Open Access   (Followers: 6)
Medio Ambiente y Urbanizacion     Full-text available via subscription  
Mediterranean Geoscience Reviews     Hybrid Journal  
Membranes     Open Access   (Followers: 3)
Metabarcoding and Metagenomics     Open Access  
Michigan Journal of Sustainability     Open Access   (Followers: 1)
Microbial Risk Analysis     Full-text available via subscription  
Microplastics and Nanoplastics     Open Access   (Followers: 1)
Mine Water and the Environment     Hybrid Journal   (Followers: 5)
Mitigation and Adaptation Strategies for Global Change     Open Access   (Followers: 8)
Modeling Earth Systems and Environment     Hybrid Journal   (Followers: 1)
Monteverdia     Open Access   (Followers: 1)

  First | 1 2 3 4 5     

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Journal Prestige (SJR): 0.645
Citation Impact (citeScore): 3
Number of Followers: 3  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2077-0375
Published by MDPI Homepage  [84 journals]
  • Membranes, Vol. 12, Pages 637: Non-Solvent Induced Phase Separation (NIPS)
           for Fabricating High Filtration Efficiency (FE) Polymeric Membranes for
           Face Mask and Air Filtration Applications

    • Authors: Ebuka A. Ogbuoji, Lauren Stephens, Amber Haycraft, Eric Wooldridge, Isabel C. Escobar
      First page: 637
      Abstract: Protection against airborne viruses has become very relevant since the outbreak of SARS-CoV-2. Nonwoven face masks along with heating, ventilation, and air conditioning (HVAC) filters have been used extensively to reduce infection rates; however, some of these filter materials provide inadequate protection due to insufficient initial filtration efficiency (FE) and FE decrease with time. Flat sheet porous membranes, which have been used extensively to filter waterborne microbes and particulate matter due to their high FE have the potential to filter air pollutants without compromising its FE over time. Therefore, in this study, single layer polysulfone (PSf) membranes were fabricated via non-solvent induced phase separation (NIPS) and were tested for airflow rate, pressure drop and FE. Polyethylene glycol (PEG) and glycerol were employed as pore-forming agents, and the effect of the primary polymer and pore-forming additive molecular weights (MW) on airflow rate and pressure drop were studied at different concentrations. The thermodynamic stability of dope solutions with different MWs of PSf and PEG in N-methylpyrrolidone (NMP) at different concentrations was determined using cloud-point measurements to construct a ternary phase diagram. Surface composition of the fabricated membranes was characterized using contact angle and X-ray photoelectron spectroscopy (XPS), while membrane morphology was characterized by SEM, and tensile strength experiments were performed to analyze the membrane mechanical strength (MS). It was observed that an increase in PSf and PEG molecular weight and concentration increased airflow and decreased pressure drop. PSf60:PEG20:NMP (15:15:70)% w/w showed the highest air flow rate and lowest pressure drop, but at the expense of the mechanical strength, which was improved significantly by attaching the membrane to a 3D-printed polypropylene support. Lastly, the FE values of the membranes were similar to those of double-layer N95 filters and significantly higher than those of single layer of N95, surgical mask and HVAC (MERV 11) filters.
      Citation: Membranes
      PubDate: 2022-06-21
      DOI: 10.3390/membranes12070637
      Issue No: Vol. 12, No. 7 (2022)
  • Membranes, Vol. 12, Pages 638: Wicking in Porous Polymeric Membranes:
           Determination of an Effective Capillary Radius to Predict the Flow
           Behavior in Lateral Flow Assays

    • Authors: Patrick Altschuh, Willfried Kunz, Marcel Bremerich, Andreas Reiter, Michael Selzer, Britta Nestler
      First page: 638
      Abstract: The working principle of lateral flow assays, such as the widely used COVID-19 rapid tests, is based on the capillary-driven liquid transport of a sample fluid to a test line using porous polymeric membranes as the conductive medium. In order to predict this wicking process by simplified analytical models, it is essential to determine an effective capillary radius for the highly porous and open-pored membranes. In this work, a parametric study is performed with selected simplified structures, representing the complex microstructure of the membrane. For this, a phase-field approach with a special wetting boundary condition to describe the meniscus formation and the corresponding mean surface curvature for each structure setup is used. As a main result, an analytical correlation between geometric structure parameters and an effective capillary radius, based on a correction factor, are obtained. The resulting correlation is verified by applying image analysis methods on reconstructed computer tomography scans of two different porous polymeric membranes and thus determining the geometric structure parameters. Subsequently, a macroscale flow model that includes the correlated effective pore size and geometrical capillary radius is applied, and the results are compared with wicking experiments. Based on the derived correction function, it is shown that the analytical prediction of the wicking process in highly porous polymeric membranes is possible without the fitting of experimental wicking data. Furthermore, it can be seen that the estimated effective pore radius of the two membranes is 8 to 10 times higher than their geometric mean pore radii.
      Citation: Membranes
      PubDate: 2022-06-21
      DOI: 10.3390/membranes12070638
      Issue No: Vol. 12, No. 7 (2022)
  • Membranes, Vol. 12, Pages 639: Construction of PPSU-MoS2/PA-MIL-101(Cr)
           Membrane with Highly Enhanced Permeance and Stability for Organic Solvent

    • Authors: Qin Liu, Xing Wu, Zongli Xie, Kaisong Zhang
      First page: 639
      Abstract: Membranes with excellent separation performance and stability are needed for organic solvent nanofiltration in industrial separation and purification processes. Here we reported a newly PPSU-MoS2/PA-MIL-101(Cr) composite membrane with high permeance, good selectivity and stability. The MIL-101(Cr) was introduced in the polyamide (PA) layer via the PIP/TMC interfacial polymerization process on a microporous PPSU-MoS2 substrate. At a small doping amount of 0.005 wt% MIL-101(Cr), the PPSU-MoS2/PA-MIL-101(Cr) composite membrane exhibited a high methanol permeance of 12.03 L m-2 h-1 bar-1, twice higher than that of the pristine membrane without sacrificing selectivity. Furthermore, embedding MIL-101(Cr) notably enhanced the stability of the composite membrane, with permeance only decreasing by 8% after a long time operation of 80 hours (pristine membrane decreased by 25%). This work demonstrated a composite membrane modified by MIL-101(Cr) with superior separation performance, which provides potential application of MOF materials for high-performance membranes in organic solvent nanofiltration and a theoretical foundation for future research in studying MOF’s influence on membrane properties.
      Citation: Membranes
      PubDate: 2022-06-21
      DOI: 10.3390/membranes12070639
      Issue No: Vol. 12, No. 7 (2022)
  • Membranes, Vol. 12, Pages 640: Multiscale Dynamics of Lipid Vesicles in
           Polymeric Microenvironment

    • Authors: Selcan Karaz, Mertcan Han, Gizem Akay, Asim Onal, Sedat Nizamoglu, Seda Kizilel, Erkan Senses
      First page: 640
      Abstract: Understanding dynamic and complex interaction of biological membranes with extracellular matrices plays a crucial role in controlling a variety of cell behavior and functions, from cell adhesion and growth to signaling and differentiation. Tremendous interest in tissue engineering has made it possible to design polymeric scaffolds mimicking the topology and mechanical properties of the native extracellular microenvironment; however, a fundamental question remains unanswered: that is, how the viscoelastic extracellular environment modifies the hierarchical dynamics of lipid membranes. In this work, we used aqueous solutions of poly(ethylene glycol) (PEG) with different molecular weights to mimic the viscous medium of cells and nearly monodisperse unilamellar DMPC/DMPG liposomes as a membrane model. Using small-angle X-ray scattering (SAXS), dynamic light scattering, temperature-modulated differential scanning calorimetry, bulk rheology, and fluorescence lifetime spectroscopy, we investigated the structural phase map and multiscale dynamics of the liposome–polymer mixtures. The results suggest an unprecedented dynamic coupling between polymer chains and phospholipid bilayers at different length/time scales. The microviscosity of the lipid bilayers is directly influenced by the relaxation of the whole chain, resulting in accelerated dynamics of lipids within the bilayers in the case of short chains compared to the polymer-free liposome case. At the macroscopic level, the gel-to-fluid transition of the bilayers results in a remarkable thermal-stiffening behavior of polymer–liposome solutions that can be modified by the concentration of the liposomes and the polymer chain length.
      Citation: Membranes
      PubDate: 2022-06-21
      DOI: 10.3390/membranes12070640
      Issue No: Vol. 12, No. 7 (2022)
  • Membranes, Vol. 12, Pages 545: Modeling and Structural Optimization of
           MSF-RO Desalination System

    • Authors: Lu He, Aipeng Jiang, Qiuyun Huang, Yan Zhao, Chuang Li, Jian Wang, Yudong Xia
      First page: 545
      Abstract: Based on the mathematical modeling and operational optimization studies of reverse osmosis (RO) and multistage flash (MSF) desalination, the structural optimization of the hybrid process was specially studied in this work with the consideration of reducing comprehensive expenses under given operational conditions. Firstly, according to the process mechanism and flowchart of the RO and MSF seawater desalination technologies, seven hybrid structures with different feed conditions were designed, and their connection equations were established for numerical calculation. Then, in order to evaluate the economic performance of the hybrid systems with different structures, the hourly average operational cost equations of RO and MSF processes were established and formulated as the comprehensive evaluation indicators. Next, with a given water production requirement, simulation calculations of the hybrid system with seven different structures were performed. The results show that the hybrid system with the fourth structure has the lowest operational cost of 4.6834 CNY/m3, and at the same time it has the lowest blowdown. However, if we take GOR or production water temperature as the target, the optimal structure of the hybrid system is the fifth or the seventh option. The obtained results are helpful in structural optimization of the hybrid system with aspects of operational cost reduction, maximum GOR, or minimizing the wastewater discharge.
      Citation: Membranes
      PubDate: 2022-05-24
      DOI: 10.3390/membranes12060545
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 546: Zero Discharge of Dyes and Regeneration of

    • Authors: Hee-Jun Kim, Uje Lee, Hyun-Woo Kim, Min Cho, Jae-Woo Lee
      First page: 546
      Abstract: Although dye removal from wastewater streams has been investigated via several approaches using adsorbents, resins, or membranes, it is still hard to avoid the fact that dyes are persistently left in the adsorption materials or washing solutions used to regenerate the used adsorbents. In particular, given that cleaning agents are composed of acid/base, organic solvents, or electrolytes, dye adsorption and adsorbent regeneration processes leave behind more hard-to-manage wastewater containing dyes. In this study, we demonstrated that cold plasma (CP) treatment, which is one of the advanced oxidation processes (AOPs), can be used for zero discharge of dyes and regeneration of a washing solution in a membrane-based dye removal process. Specifically, CP treatment was found to successfully remove dyes released from a washing process to regenerate a used membrane, thereby effectively recycling a cleaning solution. As a result, the regenerated washing solution was more favorable for the adsorbed dyes’ elution, leading to the successful regeneration of a used membrane without a significant loss of dye removal efficiency. This fact was evidenced by a comparative study on the effect of CP treatment on the reusability of membranes and washing solutions and the kinetic analysis of the AOP of the desorbed dyes. We hope that this study contributes to opening a new door for environmentally friendly and sustainable dye removal.
      Citation: Membranes
      PubDate: 2022-05-25
      DOI: 10.3390/membranes12060546
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 547: Mixed Matrix Membranes Loaded with a Porous
           Organic Polymer Having Bipyridine Moieties

    • Authors: Sandra Rico-Martínez, Cristina Álvarez, Antonio Hernández, Jesús A. Miguel, Ángel E. Lozano
      First page: 547
      Abstract: Mixed matrix membranes (MMMs), derived from three aromatic polyimides (PIs), and an affordable porous organic polymer (POP) having basic bipyridine moieties were prepared. Matrimid and two fluorinated polyimides, which were derived from 4,4′-(hexafluoroisopropylidene)diphthalic anhydride and 2,2′-bis(4-aminophenyl)hexafluoropropane (6F6F) or 2,4,6-trimethyl-m-phenylenediamine (6FTMPD), were employed as polymer matrixes. The used POP was a highly microporous material (surface area of 805 m2 g−1) with excellent thermal and chemical stability. The MMMs showed good compatibility between the PIs and POP, high thermal stabilities and glass transition temperatures superior to those of the neat PI membranes, and good mechanical properties. The addition of POP to the matrix led to an increase in the gas diffusivity and, thus, in permeability, which was associated with an increase in the fractional free volume of MMMs. The increase in permeability was higher for the less permeable matrix. For example, at 30 wt.% of POP, the permeability to CO2 and CH4 of the MMMs increased by 4- and 7-fold for Matrimid and 3- and 4-fold for 6FTMPD. The highest CH4 permeability led to a decrease in CO2/CH4 selectivity. The CO2/N2 separation performance was interesting, as the selectivity remained practically constant. Finally, the POP showed no molecular sieving effect towards the C2H4/C2H6 and C3H6/C3H8 gas pairs, but the permeability increased by about 4-fold and the selectivity was close to that of the matrix. In addition, because the POP can form metal ion bipyridine complexes, modified POP-based MMMs could be employed for olefin/paraffin separations.
      Citation: Membranes
      PubDate: 2022-05-25
      DOI: 10.3390/membranes12060547
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 548: Virtual and Artificial Cardiorespiratory
           Patients in Medicine and Biomedical Engineering

    • Authors: Krzysztof Zieliński, Tomasz Gólczewski, Maciej Kozarski, Marek Darowski
      First page: 548
      Abstract: Recently, ‘medicine in silico’ has been strongly encouraged due to ethical and legal limitations related to animal experiments and investigations conducted on patients. Computer models, particularly the very complex ones (virtual patients—VP), can be used in medical education and biomedical research as well as in clinical applications. Simpler patient-specific models may aid medical procedures. However, computer models are unfit for medical devices testing. Hybrid (i.e., numerical–physical) models do not have this disadvantage. In this review, the chosen approach to the cardiovascular system and/or respiratory system modeling was discussed with particular emphasis given to the hybrid cardiopulmonary simulator (the artificial patient), that was elaborated by the authors. The VP is useful in the education of forced spirometry, investigations of cardiopulmonary interactions (including gas exchange) and its influence on pulmonary resistance during artificial ventilation, and explanation of phenomena observed during thoracentesis. The artificial patient is useful, inter alia, in staff training and education, investigations of cardiorespiratory support and the testing of several medical devices, such as ventricular assist devices and a membrane-based artificial heart.
      Citation: Membranes
      PubDate: 2022-05-25
      DOI: 10.3390/membranes12060548
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 549: Modeling and Simulation of Lipid Membranes

    • Authors: Jordi Martí, Carles Calero
      First page: 549
      Abstract: Cell membranes separate the interior of cells and the exterior environment, providing protection, controlling the passage of substances, and governing the interaction with other biomolecules and signalling processes [...]
      Citation: Membranes
      PubDate: 2022-05-25
      DOI: 10.3390/membranes12060549
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 550: Extracellular Vesicles as Novel
           Drug-Delivery Systems through Intracellular Communications

    • Authors: Yasunari Matsuzaka, Ryu Yashiro
      First page: 550
      Abstract: Since it has been reported that extracellular vesicles (EVs) carry cargo using cell-to-cell comminication according to various in vivo situations, they are exprected to be applied as new drug-delivery systems (DDSs). In addition, non-coding RNAs, such as microRNAs (miRNAs), have attracted much attention as potential biomarkers in the encapsulated extracellular-vesicle (EV) form. EVs are bilayer-based lipids with heterogeneous populations of varying sizes and compositions. The EV-mediated transport of contents, which includes proteins, lipids, and nucleic acids, has attracted attention as a DDS through intracellular communication. Many reports have been made on the development of methods for introducing molecules into EVs and efficient methods for introducing them into target vesicles. In this review, we outline the possible molecular mechanisms by which miRNAs in exosomes participate in the post-transcriptional regulation of signaling pathways via cell–cell communication as novel DDSs, especially small EVs.
      Citation: Membranes
      PubDate: 2022-05-25
      DOI: 10.3390/membranes12060550
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 551: Membrane Fouling Control in Water Treatment

    • Authors: Yi-Li Lin
      First page: 551
      Abstract: The stress of freshwater scarcity has become a severe problem worldwide and drives the development of technologies for water recycling and reuse [...]
      Citation: Membranes
      PubDate: 2022-05-25
      DOI: 10.3390/membranes12060551
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 552: An Updated View of the Importance of
           Vesicular Trafficking and Transport and Their Role in Immune-Mediated
           Diseases: Potential Therapeutic Interventions

    • Authors: Miguel A. Ortega, Oscar Fraile-Martinez, Cielo Garcia-Montero, Miguel Angel Alvarez-Mon, Ana Maria Gomez-Lahoz, Agustin Albillos, Guillermo Lahera, Javier Quintero, Jorge Monserrat, Luis G. Guijarro, Melchor Alvarez-Mon
      First page: 552
      Abstract: Cellular trafficking is the set of processes of distributing different macromolecules by the cell. This process is highly regulated in cells, involving a system of organelles (endomembranous system), among which are a great variety of vesicles that can be secreted from the cell, giving rise to different types of extracellular vesicles (EVs) that can be captured by other cells to modulate their function. The cells of the immune system are especially sensitive to this cellular traffic, producing and releasing different classes of EVs, especially in disease states. There is growing interest in this field due to the therapeutic and translational possibilities it offers. Different ways of taking advantage of the understanding of cell trafficking and EVs are being investigated, and their use as biomarkers or therapeutic targets is being investigated. The objective of this review is to collect the latest results and knowledge in this area with a specific focus on immune-mediated diseases. Although some promising results have been obtained, further knowledge is still needed, at both the basic and translational levels, to understand and modulate cellular traffic and EVs for better clinical management of these patients.
      Citation: Membranes
      PubDate: 2022-05-25
      DOI: 10.3390/membranes12060552
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 553: Influence of the Zeolite ZSM-22 Precursor
           on a UF-PES Selective Substrate Layer for Salts Rejection

    • Authors: Nyiko M. Chauke, Richard M. Moutloali, James Ramontja
      First page: 553
      Abstract: Fabrication of the ZSM-22/Polyethersulfone (ZSM-22/PES) membranes as selective salt filters represent a growing membrane technological area in separation with the potential of high economic reward based on its low energy requirements. The incorporation of ZSM-22 zeolite material as additives into the PES polymer matrix has the prospective advantage of combining both the zeolite and polymer features while overcoming the limitations associated with both materials. This work investigated the influence of the nature of the silica precursor on ZSM-22 zeolite hydrothermally synthesised using colloidal (C60) and fumed (C60) silica to Si/Al of 60. The successful synthesis of the highly crystalline zeolitic materials was confirmed through XRD, FTIR, and SEM with EDX. The ZSM-22 additives were directly dispersed into a PES polymeric matrix to form a casting solution for the preparation of the ZSM-22/PES selective substrate layers via a phase inversion method for salts rejection. The polymeric PES was selected as an organic network in which the content of the ZSM-22 zeolite (ranging between 0 and 1.0 wt.%), was obtained and characterised by XRD, FTIR, and SEM analysis, as well as water contact angle (WCA) measurement and dead-end filtration cell. The phase inversion preparation method has induced the resulting ZSM-22/PES NF substrates anisotropy, as attributed to a high water flux to the above 700 L·m−2·h−1; high selectivity and rejection of salts to above 80% is revealed by the obtained results. The materials also exhibited improved antifouling behavior to above 70% flux recovery ratios. As such, the nature of the silica precursor influences ZSM-22 zeolite synthesis as a potential additive in the PES polymer matrix and led to the enhanced performance of the pure PES ultrafiltration membrane.
      Citation: Membranes
      PubDate: 2022-05-26
      DOI: 10.3390/membranes12060553
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 554: A Rotary Spacer System for Energy-Efficient
           Membrane Fouling Control in Oil/Water Emulsion Filtration

    • Authors: Normi Izati Mat Nawi, Afiq Mohd Lazis, Aulia Rahma, Muthia Elma, Muhammad Roil Bilad, Nik Abdul Hadi Md Nordin, Mohd Dzul Hakim Wirzal, Norazanita Shamsuddin, Hazwani Suhaimi, Norhaniza Yusof
      First page: 554
      Abstract: Membrane fouling deteriorates membrane filtration performances. Hence, mitigating membrane fouling is the key factor in sustaining the membrane process, particularly when treating fouling-prone feed, such as oil/water emulsions. The use of spacers has been expanded in the membrane module system, including for membrane fouling control. This study proposed a rotating spacer system to ameliorate membrane fouling issues when treating an oil/water emulsion. The system’s effectiveness was assessed by investigating the effect of rotating speed and membrane-to-disk gap on the hydraulic performance and the energy input and through computational fluid dynamics (CFD) simulation. The results showed that the newly developed rotary spacer system was effective and energy-efficient for fouling control. The CFD simulation results proved that the spacer rotations induced secondary flow near the membrane surface and imposed shear rate and lift force to exert fouling control. Increasing the rotation speed to an average linear velocity of 0.44 m/s increased the permeability from 126.8 ± 2.1 to 175.5 ± 2.7 Lm−2h−1bar−1. The system showed better performance at a lower spacer-to-membrane gap, in which increasing the gap from 0.5 to 2.0 cm lowered the permeability from 175.5 ± 2.7 to 126.7 ± 2.0 Lm−2h−1bar−1. Interestingly, the rotary system showed a low energy input of 1.08 to 4.08 × 10−3 kWhm−3 permeate when run at linear velocities of 0.27 to 0.44 ms−1. Overall, the findings suggest the competitiveness of the rotary spacer system as a method for membrane fouling control.
      Citation: Membranes
      PubDate: 2022-05-26
      DOI: 10.3390/membranes12060554
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 555: The Recent Development in
           Chemoresistive-Based Heterostructure Gas Sensor Technology, Their Future
           Opportunities and Challenges: A Review

    • Authors: Mir Waqas Alam, Pheiroijam Pooja, Muhammad Aamir, Basma Souayeh, Shehla Mushtaq, Muhammad Shuaib Khan, Muhammad Nasir Amin, Kaffayatullah Khan, Shanavas Shajahan
      First page: 555
      Abstract: Atmospheric pollution has become a critical problem for modern society; therefore, the research in this area continually aims to develop a high-performance gas sensor for health care and environmental safety. Researchers have made a significant contribution in this field by developing highly sensitive sensor-based novel selective materials. The aim of this article is to review recent developments and progress in the selective and sensitive detection of environmentally toxic gases. Different classifications of gas sensor devices are discussed based on their structure, the materials used, and their properties. The mechanisms of the sensing devices, identified by measuring the change in physical property using adsorption/desorption processes as well as chemical reactions on the gas-sensitive material surface, are also discussed. Additionally, the article presents a comprehensive review of the different morphologies and dimensions of mixed heterostructure, multilayered heterostructure, composite, core-shell, hollow heterostructure, and decorated heterostructure, which tune the gas-sensing properties towards hazardous gases. The article investigates in detail the growth and interface properties, concentrating on the material configurations that could be employed to prepare nanomaterials for commercial gas-sensing devices.
      Citation: Membranes
      PubDate: 2022-05-26
      DOI: 10.3390/membranes12060555
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 556: Importance of Hydroxide Ion Conductivity
           Measurement for Alkaline Water Electrolysis Membranes

    • Authors: Jun Hyun Lim, Jian Hou, Jaehong Chun, Rae Duk Lee, Jaehan Yun, Jinwoo Jung, Chang Hyun Lee
      First page: 556
      Abstract: Alkaline water electrolysis (AWE) refers to a representative water electrolysis technology that applies electricity to synthesize hydrogen gas without the production of carbon dioxide. The ideal polymer electrolyte membranes for AWE should be capable of transporting hydroxide ions (OH−) quickly in harsh alkaline environments at increased temperatures. However, there has not yet been any desirable impedance measurement method for estimating hydroxide ions’ conduction behavior across the membranes, since their impedance spectra are significantly affected by connection modes between electrodes and membranes in the test cells and the impedance evaluation environments. Accordingly, the measurement method suitable for obtaining precise hydroxide ion conductivity values through the membranes should be determined. For this purpose, Zirfon®, a state-of-the-art AWE membrane, was adopted as the standard membrane sample to perform the impedance measurement. The impedance spectra were acquired using homemade test cells with different electrode configurations in alkaline environments, and the corresponding hydroxide ion conductivity values were determined based on the electrochemical spectra. Furthermore, a modified four-probe method was found as an optimal measurement method by comparing the conductivity obtained under alkaline conditions.
      Citation: Membranes
      PubDate: 2022-05-26
      DOI: 10.3390/membranes12060556
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 557: Simultaneous Release of Silver Ions and
           10–Undecenoic Acid from Silver Iron–Oxide Nanoparticles
           Impregnated Membranes

    • Authors: Gheorghe Nechifor, Alexandra Raluca Grosu, Andreea Ferencz (Dinu), Szidonia-Katalin Tanczos, Alexandru Goran, Vlad-Alexandru Grosu, Simona Gabriela Bungău, Florentina Mihaela Păncescu, Paul Constantin Albu, Aurelia Cristina Nechifor
      First page: 557
      Abstract: The bio-medical benefits of silver ions and 10–undecenoic acid in various chemical-pharmaceutical preparations are indisputable, thus justifying numerous research studies on delayed and/or controlled release. This paper presents the effect of the polymer matrix in the simultaneous release of silver ions and 10–undecenoic acid in an aqueous medium of controlled pH and ionic strength. The study took into consideration polymeric matrices consisting of cellulose acetate (CA) and polysulfone (PSf), which were impregnated with oxide nanoparticles containing silver and 10–undecenoic acid. The studied oxide nanoparticles are nanoparticles of iron and silver oxides obtained by an accessible electrochemical method. The obtained results show that silver can be released, simultaneously with 10–undecenoic acid, from an impregnated polymeric membrane, at concentrations that ensure the biocidal and fungicidal capacity. Concentrations of active substances can be controlled by choosing the polymer matrix or, in some cases, by changing the pH of the target medium. In the studied case, higher concentrations of silver ions are released from the polysulfone matrix, while higher concentrations of 10–undecenoic acid are released from the cellulose acetate matrix. The results of the study show that a correlation can be established between the two released target substances, which is dependent on the solubility of the organic compound in the aqueous medium and the interaction of this compound with the silver ions. The ability of 10–undecenoic acid to interact with the silver ion, both through the carboxyl and alkene groups, contributes to the increase in the content of the silver ions transported in the aqueous medium.
      Citation: Membranes
      PubDate: 2022-05-27
      DOI: 10.3390/membranes12060557
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 558: Formation of a Fully Anionic Supported
           Lipid Bilayer to Model Bacterial Inner Membrane for QCM-D Studies

    • Authors: Kathleen W. Swana, Terri A. Camesano, Ramanathan Nagarajan
      First page: 558
      Abstract: Supported lipid bilayers (SLBs) on quartz crystals are employed as versatile model systems for studying cell membrane behavior with the use of the highly sensitive technique of quartz crystal microbalance with dissipation monitoring (QCM-D). Since the lipids constituting cell membranes vary from predominantly zwitterionic lipids in mammalian cells to predominantly anionic lipids in the inner membrane of Gram-positive bacteria, the ability to create SLBs of different lipid compositions is essential for representing different cell membranes. While methods to generate stable zwitterionic SLBs and zwitterionic-dominant mixed zwitterionic–anionic SLBs on quartz crystals have been well established, there are no reports of being able to form predominantly or fully anionic SLBs. We describe here a method for forming entirely anionic SLBs by treating the quartz crystal with cationic (3-aminopropyl) trimethoxysilane (APTMS). The formation of the anionic SLB was tracked using QCM-D by monitoring the adsorption of anionic lipid vesicles to a quartz surface and subsequent bilayer formation. Anionic egg L-α-phosphatidylglycerol (PG) vesicles adsorbed on the surface-treated quartz crystal, but did not undergo the vesicle-to-bilayer transition to create an SLB. However, when PG was mixed with 10–40 mole% 1-palmitoyl-2-hydroxy-sn-glycero-3-phospho-(1′-rac-glycerol) (LPG), the mixed vesicles led to the formation of stable SLBs. The dynamics of SLB formation monitored by QCM-D showed that while SLB formation by zwitterionic lipids followed a two-step process of vesicle adsorption followed by the breakdown of the adsorbed vesicles (which in turn is a result of multiple events) to create the SLB, the PG/LPG mixed vesicles ruptured immediately on contacting the quartz surface resulting in a one-step process of SLB formation. The QCM-D data also enabled the quantitative characterization of the SLB by allowing estimation of the lipid surface density as well as the thickness of the hydrophobic region of the SLB. These fully anionic SLBs are valuable model systems to conduct QCM-D studies of the interactions of extraneous substances such as antimicrobial peptides and nanoparticles with Gram-positive bacterial membranes.
      Citation: Membranes
      PubDate: 2022-05-27
      DOI: 10.3390/membranes12060558
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 559: Tailoring the Selective Permeation
           Properties of Asymmetric Cellulose Acetate/Silica Hybrid Membranes and
           Characterisation of Water Dynamics in Hydrated Membranes by Deuterium
           Nuclear Magnetic Resonance

    • Authors: Miguel P. da Silva, Maria J. Beira, Isabel D. Nogueira, Pedro J. Sebastião, João L. Figueirinhas, Maria Norberta de Pinho
      First page: 559
      Abstract: In this work, the water order and dynamics in hydrated films of flat asymmetric cellulose acetate (CA)/silica, CA/SiO2, and hybrid membranes, covering a wide range of nanofiltration (NF) and ultrafiltration (UF) permeation properties, were characterised by deuterium nuclear magnetic resonance (DNMR) relaxation. The range of NF/UF characteristics was attained by subjecting three CA/SiO2 membranes, prepared from casting solutions with different acetone/formamide ratios to drying post-treatments of solvent exchange and conditioning with surfactant mixtures. Post-treated and pristine CA/SiO2 membranes were characterised in terms of hydraulic permeability, selective permeation properties and molecular weight cut-off. These results were correlated with the DNMR relaxation findings. It was found that the post-treatment by solvent exchange caused membrane shrinkage that led to very different permeation characteristics and a significant enhancement of the DNMR relaxation observables. In contrast, conditioning with surfactant solutions exhibited a weaker effect over those properties. Scanning electron microscopy (SEM) images were obtained for the membranes post-treated with solvent exchange to confirm their asymmetric nature. This work provides an essential indication that DNMR relaxometry is a reliable tool to characterise the asymmetric porous structures of the NF/UF CA/SiO2 hybrid membranes.
      Citation: Membranes
      PubDate: 2022-05-28
      DOI: 10.3390/membranes12060559
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 560: Pectin Films with Recovered Sunflower Waxes
           Produced by Electrospraying

    • Authors: Mayra C. Chalapud, Erica R. Baümler, Amalia A. Carelli, Ma. de la Paz Salgado-Cruz, Eduardo Morales-Sánchez, Minerva Rentería-Ortega, Georgina Calderón-Domínguez
      First page: 560
      Abstract: Valorization of by-products obtained from food processing has achieved an important environmental impact. In this research, sunflower wax recovered from oil refining process was incorporated to low and high-methoxyl pectin films produced by electrospraying. Film-forming solutions and wax-added electrosprayed films were physical and structurally evaluated. The addition of sunflower wax to the film-forming solutions reduces conductivity while raising surface tension and density, whereas the type of pectin had a larger impact on viscosity, with the low-methoxyl solution having the highest value. These changes in physical solution properties influenced the film characteristics, observing thicker films with lower water vapor transmission rate (WVTR) when adding wax. Micrographs obtained by scanning electron microscopy (SEM) revealed the presence of wax particles as small spherical shapes, having a good distribution through the sectional area of films. According to X-ray diffraction (XRD), atomic force microscopy (AFM) and mechanical properties analyses, the presence of wax had an impact on the degree of crystallinity, producing a more amorphous and rougher film’s structure, without affecting the elongation percentage and the tensile stress (p>0.05). These results showed that wax addition improves the physical properties of films, while the suitability of using both pectins and the electrospraying technique was demonstrated.
      Citation: Membranes
      PubDate: 2022-05-28
      DOI: 10.3390/membranes12060560
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 561: Biopolymer-Based Mixed Matrix Membranes
           (MMMs) for CO2/CH4 Separation: Experimental and Modeling Evaluation

    • Authors: Andrea Torre-Celeizabal, Clara Casado-Coterillo, Aurora Garea
      First page: 561
      Abstract: Alternative materials are needed to tackle the sustainability of membrane fabrication in light of the circular economy, so that membrane technology keeps playing a role as sustainable technology in CO2 separation processes. In this work, chitosan (CS)-based mixed matrix thin layers have been coated onto commercial polyethersulfone (PES) supports. The CS matrix was loaded by non-toxic 1-Ethyl-3-methylimidazolium acetate ionic liquid (IL) and/or laminar nanoporous AM-4 and UZAR-S3 silicates prepared without costly organic surfactants to improve CO2 permselectivity and mechanical robustness. The CO2/CH4 separation behavior of these membranes was evaluated experimentally at different feed gas composition (CO2/CH4 feed mixture from 20:80 to 70:30%), covering different separation applications associated with this separation. A cross-flow membrane cell model built using Aspen Custom Modeler was used to validate the process performance and relate the membrane properties with the target objectives of CO2 and CH4 recovery and purity in the permeate and retentate streams, respectively. The purely organic IL-CS and mixed matrix AM-4:IL-CS composite membranes showed the most promising results in terms of CO2 and CH4 purity and recovery. This is correlated with their higher hydrophilicity and CO2 adsorption and lower swelling degree, i.e., mechanical robustness, than UZAR-S3 loaded composite membranes. The purity and recovery of the 10 wt.% AM-4:IL-CS/PES composite membrane were close or even surpassed those of the hydrophobic commercial membrane used as reference. This work provides scope for membranes fabricated from renewable or biodegradable polymers and non-toxic fillers that show at least comparable CO2/CH4 separation as existing membranes, as well as the simultaneous feedback on membrane development by the simultaneous correlation of the process requirements with the membrane properties to achieve those process targets.
      Citation: Membranes
      PubDate: 2022-05-28
      DOI: 10.3390/membranes12060561
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 562: Ibuprofen Removal by Graphene Oxide and
           Reduced Graphene Oxide Coated Polysulfone Nanofiltration Membranes

    • Authors: Asunción M. Hidalgo, María Gómez, María D. Murcia, Gerardo León, Beatriz Miguel, Israel Gago, Pilar M. Martínez
      First page: 562
      Abstract: The presence of pharmaceutical products, and their metabolites, in wastewater has become a focus of growing environmental concern. Among these pharmaceutical products, ibuprofen (IBU) is one of the most consumed non-steroidal anti-inflammatory drugs and it can enter the environment though both human and animal consumption, because it is not entirely absorbed by the body, and the pharmaceutical industry wastewater. Nanofiltration has been described as an attractive process for the treatment of wastewater containing pharmaceutical products. In this paper, the modification of a polysulfone nanofiltration membrane by coating with graphene oxide (GO) and reduced graphene oxide (RGO) has been carried out. The morphology and elemental composition of the active layer of unmodified and modified membranes were analyzed by scanning electronic microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. Initial characterization membranes was carried out, studying their water permeability coefficient and their permeate flux and rejection coefficients, at different applied pressures, using magnesium chloride solutions. The behavior of both pristine and coated membranes against ibuprofen solutions were analyzed by studying the permeate fluxes and the rejection coefficients at different pressures and at different contaminant concentrations. The results have shown that both GO and RGO coated membranes lead to higher values of ibuprofene rejection than that of uncoated membrane, the latter being the one that presents better results in the studies of permeability, selectivity, and fouling.
      Citation: Membranes
      PubDate: 2022-05-28
      DOI: 10.3390/membranes12060562
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 563: Characterization of Electrospun
           Poly(ε-caprolactone) Nano/Micro Fibrous Membrane as Scaffolds in
           Tissue Engineering: Effects of the Type of Collector Used

    • Authors: Dianney Clavijo-Grimaldo, Ciro Alfonso Casadiego-Torrado, Juan Villalobos-Elías, Adolfo Ocampo-Páramo, Magreth Torres-Parada
      First page: 563
      Abstract: Electrospinning is an electrohydrodynamic technique that transforms a polymer solution into nano/microscopic diameter fibers under the influence of a high-voltage electric field. Its use in the fabrication of nano/micro fibrous membranes as scaffolds for tissue engineering has increased rapidly in recent years due to its efficiency and reproducibility. The objective of this study is to show how the use of the same polymeric solution (polycaprolactone 9% w/v in chloroform: isopropanol 50:50) and identical electrohydrodynamic deposition parameters produces fibers with different characteristics using a flat collector platform with movements in the X and Y axes vs. a conventional rotary collector. The manufactured nano/microfibers show significant differences in most of their characteristics (morphology, roughness, hydrophilicity, and mechanical properties). Regarding the diameter and porosity of the fibers, the results were similar. Given that scaffolds must be designed to guarantee adequate survival and the proliferation and migration of a certain cell type, in this study we analyze how the variations in the characteristics of the fibers obtained are essential to defining their potential application.
      Citation: Membranes
      PubDate: 2022-05-28
      DOI: 10.3390/membranes12060563
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 564: Membrane Photobioreactor Applied for
           Municipal Wastewater Treatment at a High Solids Retention Time: Effects of
           Microalgae Decay on Treatment Performance and Biomass Properties

    • Authors: Hui Zou, Neema Christopher Rutta, Shilei Chen, Meijia Zhang, Hongjun Lin, Baoqiang Liao
      First page: 564
      Abstract: Membrane photobioreactor (MPBR) technology is a microalgae-based system that can simultaneously realize nutrient recovery and microalgae cultivation in a single step. Current research is mainly focused on the operation of MPBR at a medium SRT. The operation of MPBR at a high SRT is rarely reported in MPBR studies. Therefore, this study conducted a submerged MPBR to treat synthetic municipal wastewater at a long solids retention time of 50 d. It was found that serious microalgae decay occurred on day 23. A series of characterizations, including the biomass concentration, chlorophyll-a content, nutrients removal, and physical-chemical properties of the microalgae, were conducted to evaluate how microalgae decay affects the treatment performance and biomass properties. The results showed that the biomass concentration and chlorophyll-a/MLSS dropped rapidly from 3.48 to 1.94 g/L and 34.56 to 10.71 mg/g, respectively, after the occurrence of decay. The effluent quality significantly deteriorated, corresponding to the total effluent nitrogen and total phosphorus concentration sharply rising and exceeding that of the feed. In addition, the particle became larger, the content of the extracellular polymeric substances (EPSs) decreased, and the soluble microbial products (SMPs) increased instantaneously. However, the filtration resistance had no significant increase because of the comprehensive interactions of the floc size, EPSs, and SMPs. The above results suggest that the MPBR system cannot maintain long-term operation under a high SRT for municipal wastewater treatment. In addition, the biological treatment performance of the MPBR deteriorated while the antifouling performance of the microalgae flocs improved after the occurrence of decay. The occurrence of microalgae decay was attributed to the double stresses from the light shading and intraspecific competition under high biomass concentration. Therefore, to avoid microalgae decay, periodic biomass removal is required to control the environmental stress within the tolerance range of the microalgae. Further studies are required to explore the underlying mechanism of the occurrence of decay.
      Citation: Membranes
      PubDate: 2022-05-28
      DOI: 10.3390/membranes12060564
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 565: Engineered Approaches to Facile
           Identification of Tiny Microplastics in Polymeric and Ceramic Membrane
           Filtrations for Wastewater Treatment

    • Authors: Heejin Kook, Chanhyuk Park
      First page: 565
      Abstract: Wastewater treatment plants (WWTPs) contribute to the release of significant quantities of microplastics into the aquatic environment. The facile identification of microplastics and an understanding of their occurrence and transport through WWTPs are essential for improving microplastic retention. Potential microplastic treatment technologies for both polymeric and ceramic membrane filtrations were systematically investigated to inform decisions on the optimal choice of membrane for effective microplastic retention. A blocking filtration model, based on a simple linear regression fitting, was used in experiments on the filtration of microplastic suspensions to determine the relative importance of individual fouling mechanisms. Unlike the commonly applied spectroscopic techniques, the facile identification approaches, that are closely related to the amounts of particles within wastewater samples, attempted to identify tiny microplastics (<1.0 µm) by comparing them against silica particles for reference. A larger decline in the normalized permeate flux was observed for 0.1 μm polystyrene microplastics, while standard pore blocking appeared to be the dominant fouling mechanism for all membranes. More microplastics based on turbidity and total solids were removed using the ceramic membrane than the other polymeric membranes. However, fewer microplastics, based on the particle size distribution analysis, were removed using the ceramic membrane as the pore size measurements gave a relatively large pore size for the ceramic membrane, compared with other polymeric membranes; even though a nominal pore size of 0.1 μm for all membranes were provided by the suppliers. The contribution of microplastic-containing synthetic wastewaters to overall flux decline was significantly greater than those of identical microplastic suspensions because of the aggregation of larger microplastics with dissolved organic matter in synthetic wastewater, leading to the formation of a cake layer on the membrane surface. Despite the challenges associated with the facile identification approaches, our findings provided deeper insights and understanding of how microplastics behave in membrane filtration, which could enable the application of potential microplastic treatment technologies.
      Citation: Membranes
      PubDate: 2022-05-28
      DOI: 10.3390/membranes12060565
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 566: Evidence for a Physiological Role of T-Type
           Ca Channels in Ventricular Cardiomyocytes of Adult Mice

    • Authors: Jessica Marksteiner, Janine Ebner, Isabella Salzer, Elena Lilliu, Benjamin Hackl, Hannes Todt, Helmut Kubista, Seth Hallström, Xaver Koenig, Karlheinz Hilber
      First page: 566
      Abstract: T-type Ca channels are strongly expressed and important in the developing heart. In the adult heart, these channels play a significant role in pacemaker tissues, but there is uncertainty about their presence and physiological relevance in the working myocardium. Here, we show that the T-type Ca channel isoforms Cav3.1 and Cav3.2 are expressed at a protein level in ventricular cardiomyocytes from healthy adult C57/BL6 mice. Myocytes isolated from adult wild-type and Cav3.2 KO mice showed considerable whole cell T-type Ca currents under beta-adrenergic stimulation with isoprenaline. We further show that the detectability of basal T-type Ca currents in murine wild-type cardiomyocytes depends on the applied experimental conditions. Together, these findings reveal the presence of functional T-type Ca channels in the membrane of ventricular myocytes. In addition, electrically evoked Ca release from the sarcoplasmic reticulum was significantly impaired in Cav3.2 KO compared to wild-type cardiomyocytes. Our work implies a physiological role of T-type Ca channels in the healthy adult murine ventricular working myocardium.
      Citation: Membranes
      PubDate: 2022-05-28
      DOI: 10.3390/membranes12060566
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 567: Conversion Kinetics and Ionic Conductivity
           in Na-β”-Alumina + YSZ (Naβ”AY) Sodium Solid
           Electrolyte via Vapor Phase Conversion Process

    • Authors: Liangzhu Zhu, Anil V. Virkar
      First page: 567
      Abstract: Sodium ion batteries have been receiving increasing attention and may see potential revival in the near future, particularly in large-scale grid energy storage coupling with wind and solar power generation, due to the abundant sodium resources, low cost, and sufficiently high energy density. Among the known sodium ion conductors, the Na-β”-alumina electrolyte remains highly attractive because of its high ionic conductivity. This study focuses on the vapor phase synthesis of a Na-β”-Alumina + YSZ (Naβ”AY) composite sodium electrolyte, which has higher mechanical strength and stability than conventional single phase β”-Alumina. The objectives are the measurement of conversion kinetics through a newly developed weight-gain based model and the determination of sodium ionic conductivity in the composite electrolyte. Starting samples contained ~70 vol% α-Alumina and ~30 vol% YSZ (3 mol% Y2O3 stabilized Zirconia) with and without a thin alumina surface layer made by sintering in air at 1600 °C. The sintered samples were placed in a powder of Na-β”-alumina and heat-treated at 1250 °C for various periods. Sample dimensions and weight were measured as a function of heat treatment time. The conversion of α-Alumina in the α-Alumina + YSZ composite into Naβ”AY occurred by coupled diffusion of sodium ions through Na-β”-alumina and of oxygen ions through YSZ, effectively diffusing Na2O. From the analysis of the time dependence of sample mass and dimensions, the effective diffusion coefficient of Na2O through the sample, Deff, was estimated to be 1.74 × 10−7 cm2 s−1, and the effective interface transfer parameter, keff, was estimated as 2.33 × 10−6 cm s−1. By depositing a thin alumina coating layer on top of the bulk composite, the chemical diffusion coefficient of oxygen through single phase Na-β”-alumina was estimated as 4.35 × 10−10 cm2 s−1. An AC impedance measurement was performed on a fully converted Naβ”AY composite, and the conductivity of the composite electrolyte was 1.3 × 10−1 S cm−1 at 300 °C and 1.6 × 10−3 S cm−1 at 25 °C, indicating promising applications in solid state or molten salt batteries at low to intermediate temperatures.
      Citation: Membranes
      PubDate: 2022-05-30
      DOI: 10.3390/membranes12060567
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 568: Effect of Melissa officinalis L. Essential
           Oil Nanoemulsions on Structure and Properties of Carboxymethyl
           Chitosan/Locust Bean Gum Composite Films

    • Authors: Huijie Yu, Chi Zhang, Yao Xie, Jun Mei, Jing Xie
      First page: 568
      Abstract: This study aimed to develop active films based on carboxymethyl chitosan (CMCS)/locust bean gum (LBG) films containing Melissa officinalis L. essential oil (MOEO) nanoemulsions. The results showed that the active films incorporated with MOEO nanoemulsion resulted in an increase in the elongation of break, water resistance and improved the film hydrophilicity. Elongation of break increased from 18.49% to 27.97% with the addition of 4% MOEO nanoemulsion. Water resistance was decreased from 56.32% to 25.43%, and water contact angle was increased from 75.13 to 83.86 with the addition of 4% MOEO nanoemulsion. However, the water vapor barrier properties and tensile strength decreased with the addition of MOEO nanoemulsions. The scanning electron microscopic images and Fourier transform infrared spectroscopy results showed that the MOEO was very compatible with the film materials and dispersed evenly in the films. At the same time, the addition of MOEO nanoemulsion significantly enhanced antioxidant and antibacterial activities of C/L-MOEO films. The antioxidant and antimicrobial activities of C/L-MOEO films were increased from 7.16% to 33.81% and 3.52% to 54.50%, respectively. In general, C/L-MOEO film has great application prospects.
      Citation: Membranes
      PubDate: 2022-05-30
      DOI: 10.3390/membranes12060568
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 569: Long-Time Evaluation of Solid-State
           Composite Reference Electrodes

    • Authors: Slim Blidi, Kim Granholm, Tomasz Sokalski, Zekra Mousavi, Andrzej Lewenstam, Ivo Leito, Johan Bobacka
      First page: 569
      Abstract: In this study, the performance and long-time evaluation of solid-state composite (SSC) reference electrodes were investigated. The stability of all the SSC reference electrodes was continuously monitored by using potentiometry and electrochemical impedance spectroscopy methods over a period of several months. A multi-solution protocol was used to study the influence of the ionic strength of the sample solution, ion charge, and mobility, and the sample pH values on the performance of the reference electrodes. The SSC reference electrodes were used in the calibration of commercial indicator electrodes for different ions at different temperatures. The concentrations of K+, Na+, Ca2+, and Cl- ions and pH values were measured in river water samples at different temperatures using the SSC reference electrodes. The obtained results for the same samples were compared with the results given by an independent laboratory specialized in routine water analyses. The agreement between the results was very good and even better than the case where commercial reference electrodes were used. Our study showed that the SSC reference electrodes exhibit good long-term stability and excellent performance, both in the calibrations and analyses of environmental samples.
      Citation: Membranes
      PubDate: 2022-05-30
      DOI: 10.3390/membranes12060569
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 570: Removal of Contaminants from Water by
           Membrane Filtration: A Review

    • Authors: Jaime Cevallos-Mendoza, Célia G. Amorim, Joan Manuel Rodríguez-Díaz, Maria da Conceição B. S. M. Montenegro
      First page: 570
      Abstract: Drinking water sources are increasingly subject to various types of contamination due to anthropogenic factors and require proper treatment to remove disease-causing agents. Public drinking water systems use different treatment methods to provide safe and quality drinking water to populations. However, they are ineffective in removing contaminants that are considered a danger to the environment and therefore to humans. Several alternative treatment processes have been proposed, such as membrane filtration, as final purification methods. This paper aims to summarize the type of pollutant compounds, filtration processes, and membranes that have been most studied in this area with particular emphasis on how the modification of membranes, either the manufacturing process or the incorporation of nanomaterials, influences their performance.
      Citation: Membranes
      PubDate: 2022-05-30
      DOI: 10.3390/membranes12060570
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 571: Virucidal and Bactericidal Filtration Media
           from Electrospun Polylactic Acid Nanofibres Capable of Protecting against

    • Authors: Fabrice Noël Hakan Karabulut, Dhevesh Fomra, Günther Höfler, Naveen Ashok Chand, Gareth Wesley Beckermann
      First page: 571
      Abstract: Electrospun nanofibres excel at air filtration owing to diverse filtration mechanisms, thereby outperforming meltblown fibres. In this work, we present an electrospun polylactide acid nanofibre filter media, FilterLayrTM Eco, displaying outstanding bactericidal and virucidal properties using Manuka oil. Given the existing COVID-19 pandemic, face masks are now a mandatory accessory in many countries, and at the same time, they have become a source of environmental pollution. Made by NanoLayr Ltd., FilterLayrTM Eco uses biobased renewable raw materials with products that have end-of-life options for being industrially compostable. Loaded with natural and non-toxic terpenoid from manuka oil, FilterLayr Eco can filter up to 99.9% of 0.1 µm particles and kill >99% of trapped airborne fungi, bacteria, and viruses, including SARS-CoV-2 (Delta variant). In addition, the antimicrobial activity, and the efficacy of the filter media to filtrate particles was shown to remain highly active following several washing cycles, making it a reusable and more environmentally friendly option. The new nanofibre filter media, FilterLayrTM Eco, met the particle filtration efficiency and breathability requirements of the following standards: N95 performance in accordance with NIOSH 42CFR84, level 2 performance in accordance with ASTM F2100, and level 2 filtration efficiency and level 1 breathability in accordance with ASTM F3502. These are globally recognized facemask and respirator standards.
      Citation: Membranes
      PubDate: 2022-05-30
      DOI: 10.3390/membranes12060571
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 572: Evaluation of Different Capture Solutions
           for Ammonia Recovery in Suspended Gas Permeable Membrane Systems

    • Authors: María Soto-Herranz, Mercedes Sánchez-Báscones, Juan Manuel Antolín-Rodríguez, Pablo Martín-Ramos
      First page: 572
      Abstract: Gas permeable membranes (GPM) are a promising technology for the capture and recovery of ammonia (NH3). The work presented herein assessed the impact of the capture solution and temperature on NH3 recovery for suspended GPM systems, evaluating at a laboratory scale the performance of eight different trapping solutions (water and sulfuric, phosphoric, nitric, carbonic, carbonic, acetic, citric, and maleic acids) at 25 and 2 °C. At 25 °C, the highest NH3 capture efficiency was achieved using strong acids (87% and 77% for sulfuric and nitric acid, respectively), followed by citric and phosphoric acid (65%) and water (62%). However, a remarkable improvement was observed for phosphoric acid (+15%), citric acid (+16%), maleic acid (+22%), and water (+12%) when the capture solution was at 2 °C. The economic analysis showed that water would be the cheapest option at any working temperature, with costs of 2.13 and 2.52 €/g N (vs. 3.33 and 3.43 €/g N for sulfuric acid) in the winter and summer scenarios, respectively. As for phosphoric and citric acid, they could be promising NH3 trapping solutions in the winter months, with associated costs of 3.20 and 3.96 €/g N, respectively. Based on capture performance and economic and environmental considerations, the reported findings support that water, phosphoric acid, and citric acid can be viable alternatives to the strong acids commonly used as NH3 adsorbents in these systems.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060572
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 573: Scale Up and Validation of Novel Tri-Bore
           PVDF Hollow Fiber Membranes for Membrane Distillation Application in
           Desalination and Industrial Wastewater Recycling

    • Authors: Weikun Paul Li, Aung Thet Paing, Chin Ann Chow, Marn Soon Qua, Karikalan Mottaiyan, Kangjia Lu, Adil Dhalla, Tai-Shung Chung, Chakravarthy Gudipati
      First page: 573
      Abstract: Novel tri-bore polyvinylidene difluoride (PVDF) hollow fiber membranes (TBHF) were scaled-up for fabrication on industrial-scale hollow fiber spinning equipment, with the objective of validating the membrane technology for membrane distillation (MD) applications in areas such as desalination, resource recovery, and zero liquid discharge. The membrane chemistry and spinning processes were adapted from a previously reported method and optimized to suit large-scale production processes with the objective of translating the technology from lab scale to pilot scale and eventual commercialization. The membrane process was successfully optimized in small 1.5 kg batches and scaled-up to 20 kg and 50 kg batch sizes with good reproducibility of membrane properties. The membranes were then assembled into 0.5-inch and 2-inch modules of different lengths and evaluated in direct contact membrane distillation (DCMD) mode, as well as vacuum membrane distillation (VMD) mode. The 0.5-inch modules had a permeate flux >10 L m−2 h−1, whereas the 2-inch module flux dropped significantly to <2 L m−2 h−1 according to testing with 3.5 wt.% NaCl feed. Several optimization trials were carried out to improve the DCMD and VMD flux to >5 L m−2 h−1, whereas the salt rejection consistently remained ≥99.9%.
      Citation: Membranes
      PubDate: 2022-05-30
      DOI: 10.3390/membranes12060573
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 574: Infrared Laser-Based Single Cell
           Permeabilization by Plasma Membrane Temperature Gradients

    • Authors: Allen L. Garner, Bogdan Neculaes, Dmitry V. Dylov
      First page: 574
      Abstract: Single cell microinjection provides precise tuning of the volume and timing of delivery into the treated cells; however, it also introduces workflow complexity that requires highly skilled operators and specialized equipment. Laser-based microinjection provides an alternative method for targeting a single cell using a common laser and a workflow that may be readily standardized. This paper presents experiments using a 1550 nm, 100 fs pulse duration laser with a repetition rate of 20 ns for laser-based microinjection and calculations of the hypothesized physical mechanism responsible for the experimentally observed permeabilization. Chinese Hamster Ovarian (CHO) cells exposed to this laser underwent propidium iodide uptake, demonstrating the potential for selective cell permeabilization. The agreement between the experimental conditions and the electropermeabilization threshold based on estimated changes in the transmembrane potential induced by a laser-induced plasma membrane temperature gradient, even without accounting for enhancement due to traditional electroporation, strengthens the hypothesis of this mechanism for the experimental observations. Compared to standard 800 nm lasers, 1550 nm fs lasers may ultimately provide a lower cost microinjection method that readily interfaces with a microscope and is agnostic to operator skill, while inducing fewer deleterious effects (e.g., temperature rise, shockwaves, and cavitation bubbles).
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060574
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 575: Effect of Operating Conditions and Fructans
           Size Distribution on Tight Ultrafiltration Process for Agave Fructans
           Fractionation: Optimization and Modeling

    • Authors: Noe Luiz-Santos, Rogelio Prado-Ramírez, Rosa María Camacho-Ruíz, Guadalupe María Guatemala-Morales, Enrique Arriola-Guevara, Lorena Moreno-Vilet
      First page: 575
      Abstract: The objective of this work was to evaluate the effect of operating conditions and fructans size distribution on the tight Ultrafiltration process for agave fructans fractionation. A mathematical model of limiting mass flux transfer was used to represent the profile of concentrations over time at the outlet of a pilot scale ultrafiltration system. First, a Box-Behnken experimental design was performed for the optimization of the parameters that determine the operating conditions in their respective ranges: temperature, 30–60 °C; transmembrane pressure (TMP), 1–5 bar and feed concentration, 50–150 kg∙m−3, on the separation factor (SF) and permeate flux. Then, the validation of the model for different fructans size distribution was carried out. The results showed that for SF, the quadratic terms of temperature, TMP and feed concentration were the most significant factors. Statistical analysis revealed that the temperature-concentration interaction has a significant effect (p < 0.005) and that the optimal conditions were: 46.81 °C, 3.27 bar and 85.70 kg∙m−3. The optimized parameters were used to validate the hydrodynamic model; the adjustments conclude that the model, although simplified, is capable of correctly reproducing the experimental data of agave fructans fractionation by a tight ultrafiltration pilot unit. The fractionation process is favored at higher proportions of FOS:Fc in native agave fructans.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060575
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 576: Development of New Biodegradable
           Agar-Alginate Membranes for Food Packaging

    • Authors: Sonia Amariei, Florin Ursachi, Ancuţa Petraru
      First page: 576
      Abstract: The paper analyzes the possibility of replacing the polyethylene packaging from food products with biodegradable packaging obtained from biopolymers. The proposed packaging materials were obtained from polysaccharides (alginate, agar), glycerol as plasticizer. To improve the properties necessary for the coating materials, two groups of membranes were made, one with ascorbic acid (AA, 0.1–0.45 g) in 150 mL filmogenic solution and the other with calcium chloride (CaCl2, 0.02–0.1 g) in 150 mL filmogenic solution. The membranes were analyzed for mechanical properties, light transmission, transparency and barrier properties (water vapor, oxygen, or fatty substances). The results demonstrated that the addition of AA (0.1 g), increases tensile strength, transparency, oxygen and water barrier properties. On the other hand, the addition of calcium chloride (0.08 g) increased the hardness, tensile strength and opacity of the membranes. Moreover, it ensured a uniform distribution of the mixture components. The uniformization of the mixture components in the presence of AA and CACl2 was observed by SEM and roughness analysis. Hydrogen bonding interactions between the biopolymers and the additives used were highlighted by FTIR analysis. All membranes have shown very good UV absorption. The results suggest that agar/alginate/glycerol membranes with AA and CaCl2 have the potential to be used in an active food packaging system.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060576
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 577: Morphology Effect of Zinc Oxide
           Nanoparticles on the Gas Separation Performance of Polyurethane Mixed
           Matrix Membranes for CO2 Recovery from CH4, O2, and N2

    • Authors: Tatyana Sergeevna Sazanova, Kirill Alexandrovich Smorodin, Dmitriy Mikhailovich Zarubin, Kseniia Vladimirovna Otvagina, Alexey Andreevich Maslov, Artem Nikolaevich Markov, Diana Georgievna Fukina, Alla Evgenievna Mochalova, Leonid Alexandrovich Mochalov, Artem Anatolevich Atlaskin, Andrey Vladimirovich Vorotyntsev
      First page: 577
      Abstract: The effect of the morphology and content of zinc oxide nanoparticles (ZnO-NPs) on the physicochemical, mechanical, and gas transport properties of the polyurethane (PU) mixed matrix membranes (MMMs) with respect to CO2 recovery from CH4, O2, and N2 was studied. The MMMs based on PU with spherical and rod-shaped ZnO-NPs at various loadings, namely, 0.05, 0.1, 0.5, 1, and 2 wt. %, were prepared with membrane density control and studied using AFM, wettability measurements, surface free energy calculation, gas separation and mechanical testing. To evaluate the resistance of the ZnO-NPs to agglomeration in the polymer solutions, zeta potential was determined. The ZnO-NPs with average cross sectional size of 30 nm were obtained by plasma-enhanced chemical vapor deposition (PECVD) from elemental high-purity zinc in a zinc-oxygen-hydrogen plasma-forming gas mixture. It was established that the spherical ZnO-NPs are promising to improve the gas performance of PU-based MMMs for CO2 recovery from natural gas, while the rod-shaped NPs better demonstrate their potential in capturing CO2 in flue gases.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060577
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 578: Quantitative Proteomics Reveals That ADAM15
           Can Have Proteolytic-Independent Functions in the Steady State

    • Authors: Chun-Yao Yang, Simone Bonelli, Matteo Calligaris, Anna Paola Carreca, Stephan A. Müller, Stefan F. Lichtenthaler, Linda Troeberg, Simone D. Scilabra
      First page: 578
      Abstract: A disintegrin and metalloproteinase 15 (ADAM15) is a member of the ADAM family of sheddases. Its genetic ablation in mice suggests that ADAM15 plays an important role in a wide variety of biological functions, including cartilage homeostasis. Nevertheless, while the substrate repertoire of other members of the ADAM family, including ADAM10 and ADAM17, is largely established, little is known about the substrates of ADAM15 and how it exerts its biological functions. Herein, we used unbiased proteomics to identify ADAM15 substrates and proteins regulated by the proteinase in chondrocyte-like HTB94 cells. ADAM15 silencing did not induce major changes in the secretome composition of HTB94 cells, as revealed by two different proteomic approaches. Conversely, overexpression of ADAM15 remodeled the secretome, with levels of several secreted proteins being altered compared to GFP-overexpressing controls. However, the analysis did not identify potential substrates of the sheddase, i.e., transmembrane proteins released by ADAM15 in the extracellular milieu. Intriguingly, secretome analysis and immunoblotting demonstrated that ADAM15 overexpression increased secreted levels of tissue inhibitor of metalloproteinases 3 (TIMP-3), a major regulator of extracellular matrix turnover. An inactive form of ADAM15 led to a similar increase in the inhibitor, indicating that ADAM15 regulates TIMP-3 secretion by an unknown mechanism independent of its catalytic activity. In conclusion, high-resolution quantitative proteomics of HTB94 cells manipulated to have increased or decreased ADAM15 expression did not identify canonical substrates of the proteinase in the steady state, but it revealed that ADAM15 can modulate the secretome in a catalytically-independent manner.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060578
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 579: Experimental Determination of Hydrogen
           Isotope Transport Parameters in Vanadium

    • Authors: Marta Malo, Igor Peñalva, Jon Azkurreta, Belit Garcinuño, Hao-Dong Liu, David Rapisarda, Hai-Shan Zhou, Guang-Nan Luo
      First page: 579
      Abstract: Deuterium permeation through vanadium membranes in a wide range of pressures and the temperature range ~250–550 °C was experimentally investigated. Measurements on the same material were carried out in three laboratories with different features for an extended characterization and for cross-check validation. A unified equation for deuterium permeability in pure vanadium (99%) was provided as Ф = 1.27 ×10−4·e−8667/T mol m−1 s−1 Pa−0.5, which represents a significant progress for the characterization of the transport properties in this material, given the spread of data, which can currently be found in the literature. Adsorption and recombination rate constants were also measured for hydrogen and deuterium at low pressure for the same range of temperatures. Finally, the influence of the surface roughness was examined by measuring samples with different surface finish.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060579
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 580: Modification of Polyacrylonitrile

    • Authors: Anthony Arvind Kishore Chand, Barbara Bajer, Erik S. Schneider, Tomi Mantel, Mathias Ernst, Volkan Filiz, Sarah Glass
      First page: 580
      Abstract: Ion adsorbing ultrafiltration membranes provide an interesting possibility to remove toxic ions from water. Furthermore, it is also possible to recover valuable elements. In this work, we demonstrate two easy strategies to modify polyacrylonitrile membranes with anion and cation adsorbing groups. The membranes were modified to have positively charged amine groups or negatively charged carboxyl groups. The success of the reactions was confirmed using IR spectroscopy and zeta-potential measurements. The membranes carrying negatively charged groups provided a negative zeta-potential and had an isoelectric point at pH 3.6, while the membranes carrying positively charged groups had a positive zeta-potential in the analyzed pH range. Since only the surface of the polymer was modified, the pore size and permeance of the membranes were not drastically affected. The membranes prepared by both modification strategies had a pure water permeance higher than 1000 L/(m2 h bar) and a water contact angle of 44.3 and 57.2°, respectively. Therefore, the membranes can be operated at low pressures with reasonable flux. Additionally, SEM images showed that the membranes were still open-pored. Adsorption tests using a positively and a negatively charged dye as well as a toxic cation and an anion were performed to analyze the adsorption behavior. Both membranes were able to adsorb the oppositely charged dyes as well as the copper and chromate ions. Therefore, these membranes are good candidates to purify water streams containing hazardous ions.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060580
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 581: Wood-Based Cellulose-Rich Ultrafiltration
           Membranes: Alkaline Coagulation Bath Introduction and Investigation of Its
           Effect over Membranes’ Performance

    • Authors: Anastasiia Lopatina, Alma Liukkonen, Sabina Bec, Ikenna Anugwom, Joona Nieminen, Mika Mänttäri, Mari Kallioinen-Mänttäri
      First page: 581
      Abstract: In this study, wood-based cellulose-rich membranes were produced with a novel approach to casting procedure. Flat-sheet membranes were prepared from birch biomass pretreated with deep eutectic solvent and dissolved in ionic liquid–dimethylsulfoxide system via phase inversion method. Alkaline coagulation bath filled with sodium hydroxide solution was added to the process before a water coagulation bath and aimed to improve membranes’ performance. The effect of NaOH coagulation bath on the membrane was studied based on two NaOH concentrations and two different treatment times. The characterisation methods included measuring pure water permeabilities, polyethylene glycol 35 kDa model solution retentions, hydrophilicity, zeta potential, and chemical structure. Additionally, suitability of the membranes for removing residual phosphorous from a municipal wastewater treatment plant’s effluent was studied. The study revealed that introduction of the alkaline coagulation bath led to additional removal of lignin from membrane matrix and increase in the filtration capacity up to eight times. The resulting membranes can be characterised as very hydrophilic, with contact angle values 11.9–18.2°, negatively charged over a wide pH range. The membranes with the highest permeability, 380–450 L/m2·h·bar, showed approximately 70% phosphorus removal from purified wastewater, good removal of suspended solids, and low irreversible fouling tendency.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060581
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 582: Ionomer Membranes Produced from
           Hexaarylbenzene-Based Partially Fluorinated Poly(arylene ether) Blends for
           Proton Exchange Membrane Fuel Cells

    • Authors: Tzu-Sheng Huang, Hsin-Yi Wen, Yi-Yin Chen, Po-Hao Hung, Tung-Li Hsieh, Wen-Yao Huang, Mei-Ying Chang
      First page: 582
      Abstract: In this study, a series of high molecular weight ionomers of hexaarylbenzene-- and fluorene-based poly(arylene ether)s were synthesized conveniently through condensation and post-sulfonation modification. The use a of blending method might increase the stacking density of chains and affect the formation both of interchain and intrachain proton transfer clusters. Multiscale phase separation caused by the dissolution and compatibility differences of blend ionomer in high-boiling-point solvents was examined through analysis and simulations. The blend membranes produced in this study exhibited a high proton conductivity of 206.4 mS cm−1 at 80 °C (increased from 182.6 mS cm−1 for precursor membranes), excellent thermal resistance (decomposition temperature >200 °C), and suitable mechanical properties with a tensile strength of 73.8–77.4 MPa. As a proton exchange membrane for fuel cell applications, it exhibits an excellent power efficiency of approximately 1.3 W cm−2. Thus, the ionomer membranes have strong potential for use in proton exchange membrane fuel cells and other electrochemical applications.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060582
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 583: Flexible Membranes for Batteries and
           Supercapacitor Applications

    • Authors: Glukhova
      First page: 583
      Abstract: Modern portable electronic devices, roll-up displays and wearable systems for personal multimedia devices require flexible energy storage devices. [...]
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060583
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 584: The Effect of Solution Casting Temperature
           and Ultrasound Treatment on PEBAX MH-1657/ZIF-8 Mixed Matrix Membranes
           Morphology and Performance

    • Authors: Elsa Lasseuguette, Louise Fielder-Dunton, Qian Jian, Maria-Chiara Ferrari
      First page: 584
      Abstract: Approximately two-thirds of anthropogenic emissions causing global warming are from carbon dioxide. Carbon capture is essential, with membranes proving to be a low cost and energy-efficient solution to alternative technologies. In particular, mixed matrix membranes (MMMs) can have higher permeability and selectivity than pure polymer membranes. The fabrication conditions affect the formation of defects within the membranes. In this work, MMMs were created using a PEBAX MH-1657 polymer and a ZIF-8 filler. The effect of casting plate temperature, varying from −5 °C to 50 °C, and the effect of ultrasound treatment time (80–400 min) and method (filler solution only, filler and polymer combined solution only and filler solution followed by combined solution) were investigated, aiming to reduce defect formations hence improving the performance of the MMMs. SEM images and permeation tests using pure CO2 and N2 gas, replicating flue gas for carbon capture, were used to investigate and compare the membranes morphology and performance. The results indicated that the MMMs maintained their permeabilities and selectivities at all tested casting temperatures. However, the neat PEBAX membranes demonstrated increased phase separation of the polyamide and polyether oxide phases at higher temperatures, causing a reduction in permeability due to the higher crystallinity degree, confirmed by DSC experiment. The MMMs fabricated at low ultrasound times displayed a large amount of aggregation with large particle size causing channeling. At high ultrasound times, a well-dispersed filler with small filler diameters was observed, providing a high membrane performance. Overall, defect-free membranes were successfully fabricated, leading to improved performance, with the best membrane resulting from the longest ultrasound time reaching the Robeson bound upper limits.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060584
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 585: Biorefinery of Tomato Leaves by Integrated
           Extraction and Membrane Processes to Obtain Fractions That Enhance Induced
           Resistance against Pseudomonas syringae Infection

    • Authors: Fabio Bazzarelli, Rosalinda Mazzei, Emmanouil Papaioannou, Vasileios Giannakopoulos, Michael R. Roberts, Lidietta Giorno
      First page: 585
      Abstract: Tomato leaves have been shown to contain significant amounts of important metabolites involved in protection against abiotic and biotic stress and/or possessing important therapeutic properties. In this work, a systematic study was carried out to evaluate the potential of a sustainable process for the fractionation of major biomolecules from tomato leaves, by combining aqueous extraction and membrane processes. The extraction parameters (temperature, pH, and liquid/solid ratio (L/S)) were optimized to obtain high amounts of biomolecules (proteins, carbohydrates, biophenols). Subsequently, the aqueous extract was processed by membrane processes, using 30–50 kDa and 1–5 kDa membranes for the first and second stage, respectively. The permeate from the first stage, which was used to remove proteins from the aqueous extract, was further fractionated in the second stage, where the appropriate membrane material was also selected. Of all the membranes tested in the first stage, regenerated cellulose membranes (RC) showed the best performance in terms of higher rejection of proteins (85%) and lower fouling index (less than 15% compared to 80% of the other membranes tested), indicating that they are suitable for fractionation of proteins from biophenols and carbohydrates. In the second stage, the best results were obtained by using polyethersulfone (PES) membranes with an NMWCO of 5 kDa, since the greatest difference between the rejection coefficients of carbohydrates and phenolic compounds was obtained. In vivo bioactivity tests confirmed that fractions obtained with PES 5 kDa membranes were able to induce plant defense against P. syringae.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060585
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 586: Microfluidics and MEMS Technology for

    • Authors: Jasmina Casals-Terré
      First page: 586
      Abstract: Nowadays manufacturing processes at nano and microscale provide reliable platform for the development of novel applications, specially in the membrane’s field [...]
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060586
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 587: The Biological Performance of a Novel
           Electrokinetic-Assisted Membrane Photobioreactor (EK-MPBR) for Wastewater

    • Authors: Maryam Amini, Eltayeb Mohamedelhassan, Baoqiang Liao
      First page: 587
      Abstract: Developing an effective phycoremediation system, especially by utilizing microalgae, could provide a valuable approach in wastewater treatment for simultaneous nutrient removal and biomass generation, which would help control environmental pollution. This research aims to study the impact of low-voltage direct current (DC) application on Chlorella vulgaris properties and the removal efficiency of nutrients (N and P) in a novel electrokinetic-assisted membrane photobioreactor (EK-MPBR) in treating synthetic municipal wastewater. Two membrane photobioreactors ran in parallel for 49 days with and without an applied electric field (current density: 0.261 A/m2). Mixed liquid suspended soils (MLSS) concentration, chemical oxygen demand (COD), floc morphology, total phosphorus (TP), and total nitrogen (TN) removals were measured during the experiments. The results showed that EK-MPBR achieved biomass production comparable to the control MPBR. In EK-MPBR, an over 97% reduction in phosphate concentration was achieved compared to 41% removal in the control MPBR. The control MPBR outperformed the nitrogen removal of EK-MPBR (68% compared to 43% removal). Induced DC electric field led to lower pH, lower zeta potential, and smaller particle sizes in the EK-MPBR as compared with MPBR. The results of this novel study investigating the incorporation of Chlorella vulgaris in an electrokinetic-assisted membrane photobioreactor indicate that this is a promising technology for wastewater treatment.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060587
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 588: Development of 3D ZnO-CNT Support
           Structures Impregnated with Inorganic Salts

    • Authors: Stefania Chiriac, Maria-Eliza Puscasu, Ioan Albert Tudor, Alexandru Cristian Matei, Laura Madalina Cursaru, Radu Robert Piticescu
      First page: 588
      Abstract: Carbon-based materials are promising candidates for enhancing thermal properties of phase change materials (PCMs) without lowering its energy storage capacity. Nowadays, researchers are trying to find a proper porous structure as PCMs support for thermal energy storage applications. In this context, the main novelty of this paper consists in using a ZnO-CNT-based nanocomposite powder, prepared by an own hydrothermal method at high pressure, to obtain porous 3D printed support structures with embedding capacity of PCMs. The morphology of 3D structures, before and after impregnation with three PCMs inorganic salts (NaNO3, KNO3 and NaNO3:KNO3 mixture (1:1 vol% saturated solution) was investigated by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX). For structure impregnated with nitrates mixture, SEM cross-section morphology suggest that the inorganic salts impregnation started into micropores, continuing with the covering of the 3D structure surface and epitaxial growing of micro/nanostructured crystals, which led to reducing the distance between the structural strands. The variation of melting/crystallization points and associated enthalpies of impregnated PCMs and their stability during five repeated thermal cycles were studied by differential scanning calorimetry (DSC) and simultaneous DSC-thermogravimetry (DSC-TGA). From the second heating-cooling cycle, the 3D structures impregnated with NaNO3 and NaNO3-KNO3 mixture are thermally stable.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060588
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 589: Incorporating Carbon Nanotubes in
           Nanocomposite Mixed-Matrix Membranes for Gas Separation: A Review

    • Authors: Aimi Farzana Yazid, Hilmi Mukhtar, Rizwan Nasir, Dzeti Farhah Mohshim
      First page: 589
      Abstract: Carbon nanotube (CNT) is a prominent material for gas separation due to its inherent smoothness of walls, allowing rapid transport of gases compared to other inorganic fillers. It also possesses high mechanical strength, enabling membranes to operate at high pressure. Although it has superior properties compared to other inorganic fillers, preparation of CNTs into a polymer matrix remains challenging due to the strong van der Waals forces of CNTs, which lead to agglomeration of CNTs. To utilize the full potential of CNTs, proper dispersion of CNTs must be addressed. In this paper, methods to improve the dispersion of CNTs using functionalization methods were discussed. Fabrication techniques for CNT mixed-matrix membrane (MMM) nanocomposites and their impact on gas separation performance were compared. This paper also reviewed the applications and potential of CNT MMMs in gas separation.
      Citation: Membranes
      PubDate: 2022-05-31
      DOI: 10.3390/membranes12060589
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 590: Solution-Processed Silicon Doped Tin Oxide
           Thin Films and Thin-Film Transistors Based on Tetraethyl Orthosilicate

    • Authors: Ziyan He, Xu Zhang, Xiaoqin Wei, Dongxiang Luo, Honglong Ning, Qiannan Ye, Renxu Wu, Yao Guo, Rihui Yao, Junbiao Peng
      First page: 590
      Abstract: Recently, tin oxide (SnO2) has been the preferred thin film material for semiconductor devices such as thin-film transistors (TFTs) due to its low cost, non-toxicity, and superior electrical performance. However, the high oxygen vacancy (VO) concentration leads to poor performance of SnO2 thin films and devices. In this paper, with tetraethyl orthosilicate (TEOS) as the Si source, which can decompose to release heat and supply energy when annealing, Si doped SnO2 (STO) films and inverted staggered STO TFTs were successfully fabricated by a solution method. An XPS analysis showed that Si doping can effectively inhibit the formation of VO, thus reducing the carrier concentration and improving the quality of SnO2 films. In addition, the heat released from TEOS can modestly lower the preparation temperature of STO films. By optimizing the annealing temperature and Si doping content, 350 °C annealed STO TFTs with 5 at.% Si exhibited the best device performance: Ioff was as low as 10−10 A, Ion/Ioff reached a magnitude of 104, and Von was 1.51 V. Utilizing TEOS as an Si source has a certain reference significance for solution-processed metal oxide thin films in the future.
      Citation: Membranes
      PubDate: 2022-06-01
      DOI: 10.3390/membranes12060590
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 591: Ultra-Low-Pressure Membrane Filtration for
           Simultaneous Recovery of Detergent and Water from Laundry Wastewater

    • Authors: Yusran Khery, Sonia Ely Daniar, Normi Izati Mat Nawi, Muhammad Roil Bilad, Yusuf Wibisono, Baiq Asma Nufida, Ahmadi Ahmadi, Juhana Jaafar, Nurul Huda, Rovina Kobun
      First page: 591
      Abstract: Reusing water and excess detergent from the laundry industry has become an attractive method to combat water shortages. Membrane filtration is considered an advanced technique and highly attractive due to its excellent advantages. However, the conventional membrane filtration method suffers from membrane fouling, which restricts its performance and diminishes its economic viability. This study assesses the preliminary performance of submerged, gravity-driven membrane filtration—under ultra-low trans-membrane pressure (△P) of <0.1 bar—to combat membrane fouling issues for detergent and water recovery from laundry wastewater. The results show that even under ultra-low pressure, the membrane suffered from compaction that lowered its permeability by 14% under △P of 6 and 10 kPa, with corresponding permeabilities of 2085 ± 259 and 1791 ± 42 L/(m2 h bar). Filtration of a detergent solution also led to up to 8% permeability loss due to membrane fouling. During the filtration of laundry wastewater, 80–91% permeability loss was observed, leading to the lowest flux of 15.6 L/(m2·h) at △P of 10 kPa, 38% lower than △P of 6 kPa (of 25.2 L/(m2·h)). High △P led to both the membrane and the foulant compaction inflating the filtration resistance. The system could recover 83.6% of excess residual detergent, while most micelles were rejected (ascribed from 71% of COD removal). The TDS content could not be retained, disallowing maximum resource recovery. A gravity-driven filtration system can be self-sustained with minimum supervision in residential and industrial laundries. Nevertheless, a detailed study on long-term filtration performance and multiple cleaning cycles is still required in the future.
      Citation: Membranes
      PubDate: 2022-06-01
      DOI: 10.3390/membranes12060591
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 592: Preparation and Properties of Polyimide
           Composite Membrane with High Transmittance and Surface Hydrophobicity for
           Lightweight Optical System

    • Authors: Jiajia Yin, Haohao Hui, Bin Fan, Jiang Bian, Junfeng Du, Hu Yang
      First page: 592
      Abstract: Polyimide membranes have excellent physiochemical properties which make them valuable materials for optical area. However, common aromatic polyimide membrane trend to show low transmittance in visible region because of the charge-transfer complex (CTC) in molecular structures. Moreover, it’s trending to show high moisture uptakes because of the hydrophilic imide rings in molecular structure. In this work, a polyimide composite membrane with SiO2 antireflective membrane on both sides was prepared. High transmittance (93% within 500~800 nm) and surface hydrophobicity was realized simultaneously. The polyimide composite membrane showed great optical homogeneity. The SiO2 antireflective membranes on polyimide substrate were prepared through a simple and efficient sol-gel method. The surface roughness of polyimide membrane substrate on each side has been improved to 1.56 nm and 3.14 nm, respectively. Moreover, the excellent thermal stability and mechanical property of polyimide membrane has been preserved, which greatly improves the range of applications for the composite membrane. It is a good candidate for light weight optical system.
      Citation: Membranes
      PubDate: 2022-06-03
      DOI: 10.3390/membranes12060592
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 593: Progress on Crowding Effect in Cell-like

    • Authors: Chao Li, Xiangxiang Zhang, Mingdong Dong, Xiaojun Han
      First page: 593
      Abstract: Several biological macromolecules, such as proteins, nucleic acids, and polysaccharides, occupy about 30% of the space in cells, resulting in a crowded macromolecule environment. The crowding effect within cells exerts an impact on the functions of biological components, the assembly behavior of biomacromolecules, and the thermodynamics and kinetics of metabolic reactions. Cell-like structures provide confined and independent compartments for studying the working mechanisms of cells, which can be used to study the physiological functions arising from the crowding effect of macromolecules in cells. This article mainly summarizes the progress of research on the macromolecular crowding effects in cell-like structures. It includes the effects of this crowding on actin assembly behavior, tubulin aggregation behavior, and gene expression. The challenges and future trends in this field are presented at the end of the paper.
      Citation: Membranes
      PubDate: 2022-06-03
      DOI: 10.3390/membranes12060593
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 594: Fabrication and Characterization of
           Orodispersible Composite Film from Hydroxypropylmethyl
           Cellulose-Crosslinked Carboxymethyl Rice Starch

    • Authors: Ornanong S. Kittipongpatana, Karnkamol Trisopon, Phanphen Wattanaarsakit, Nisit Kittipongpatana
      First page: 594
      Abstract: Crosslinked carboxymethyl rice starch (CLCMRS), prepared via dual modifications of native rice starch (NRS) with chloroacetic acid and sodium trimetaphosphate, was employed to facilitate the disintegration of hydroxypropylmethylcellulose (HPMC) orodispersible films (ODFs), with or without the addition of glycerol. Fabricated by using the solvent casting method, the composite films, with the HPMC--LCMRS ratios of 9:1, 7:1, 5:1 and 4:1, were then subjected to physicochemical and mechanical evaluations, including weight, thickness, moisture content and moisture absorption, swelling index, transparency, folding endurance, scanning electron microscopy, Fourier transform infrared spectroscopy, tensile strength, elongation at break, and Young’s modulus, as well as the determination of disintegration time by using the Petri dish method (PDM) and slide frame and bead method (SFM). The results showed that HPMC-CLCMRS composite films exhibited good film integrity, uniformity, and transparency with up to 20% CLCMRS incorporation (4:1 ratio). Non-plasticized composite films showed no significant changes in the average weight, thickness, density, folding endurance (96–122), tensile strength (2.01–2.13 MPa) and Young’s modulus (10.28–11.59 MPa) compared to HPMC film (135, 2.24 MPa, 10.67 MPa, respectively). On the other hand, the moisture content and moisture absorption were slightly higher, whereas the elongation at break (EAB; 4.31–5.09%) and the transparency (4.73–6.18) were slightly lowered from that of the HPMC film (6.03% and 7.03%, respectively). With the addition of glycerol as a plasticizer, the average weight and film thickness increased, and the density decreased. The folding endurance was improved (to >300), while the transparency remained in the acceptable range. Although the tensile strength of most composite films decreased (0.66–1.75 MPa), they all exhibited improved flexibility (EAB 7.27–11.07%) while retaining structural integrity. The disintegration times of most composite films (PDM 109–331, SFM 70–214 s) were lower than those of HPMC film (PDM 345, SFM 229 s). In conclusion, the incorporation of CLCMRS significantly improved the disintegration time of the composite films whereas it did not affect or only slightly affected the physicochemical and mechanical characteristics of the films. The 5:1 and 4:1 HPMC:CLCMRS composite films, in particular, showed promising potential application as a film base for the manufacturing of orodispersible film dosage forms.
      Citation: Membranes
      PubDate: 2022-06-04
      DOI: 10.3390/membranes12060594
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 595: Spider Toxin SNX-482 Gating Modifier
           Spontaneously Partitions in the Membrane Guided by Electrostatic

    • Authors: Guido Mellado, Nicolas Espinoza, Jose Antonio Garate, Alan Neely
      First page: 595
      Abstract: Spider toxin SNX-482 is a cysteine-rich peptide that interferes with calcium channel activity by binding to voltage-sensing domains of the CaV2.3 subtype. Two mechanisms dominate the binding process of cysteine-rich peptides.: direct binding from the aqueous phase or through lateral diffusion from the membrane, the so-called reduction in dimensionality mechanism. In this work, via coarse-grained and atomistic molecular dynamics simulations, we have systematically studied the spontaneous partitioning of SNX-482 with membranes of different anionic compositions and explored via diffusional analysis both binding mechanisms. Our simulations revealed a conserved protein patch that inserts in the membrane, a preference for binding towards partially negatively charged membranes, and that electrostatics guides membrane binding by incrementing and aligning the molecular dipole. Finally, diffusivity calculations showed that the toxin diffusion along the membrane plane is an order of magnitude slower than the aqueous phase suggesting that the critical factor in determining the SNX-482-CaV2.3 binding mechanism is the affinity between the membrane and SNX-482.
      Citation: Membranes
      PubDate: 2022-06-06
      DOI: 10.3390/membranes12060595
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 596: Investigating the Permeation Mechanism of
           Typical Phthalic Acid Esters (PAEs) and Membrane Response Using Molecular
           Dynamics Simulations

    • Authors: Yiqiong Bao, Mengrong Li, Yanjie Xie, Jingjing Guo
      First page: 596
      Abstract: Phthalic acid esters (PAEs) are typical environmental endocrine disrupters, interfering with the endocrine system of organisms at very low concentrations. The plasma membrane is the first barrier for organic pollutants to enter the organism, so membrane permeability is a key factor affecting their biological toxicity. In this study, based on computational approaches, we investigated the permeation and intramembrane aggregation of typical PAEs (dimethyl phthalate, DMP; dibutyl phthalate, DBP; di-2-ethyl hexyl phthalate, DEHP), as well as their effects on membrane properties, and related molecular mechanisms were uncovered. Our results suggested that PAEs could enter the membrane spontaneously, preferring the headgroup-acyl chain interface of the bilayer, and the longer the side chain (DEHP > DBP > DMP), the deeper the insertion. Compared with the shortest DMP, DEHP apparently increased membrane thickness, order, and rigidity, which might be due to its stronger hydrophobicity. Potential of means force (PMF) analysis revealed the presence of an energy barrier located at the water-membrane interface, with a maximum value of 2.14 kcal mol−1 obtained in the DEHP-system. Therefore, the difficulty of membrane insertion is also positively correlated with the side-chain length or hydrophobicity of PAE molecules. These findings will inspire our understanding of structure-activity relationship between PAEs and their effects on membrane properties, and provide a scientific basis for the formulation of environmental pollution standards and the prevention and control of small molecule pollutants.
      Citation: Membranes
      PubDate: 2022-06-06
      DOI: 10.3390/membranes12060596
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 597: A Comprehensive Analysis of Inorganic Ions
           and Their Selective Removal from the Reconstituted Tobacco Extract Using

    • Authors: Shaolin Ge, Qian Chen, Zhao Zhang, Shike She, Bingxia Xu, Fei Liu, Noor Ul Afsar
      First page: 597
      Abstract: Many tobacco stalks, dust, and fines are discharged in the tobacco industry, rich in inorganic minerals ions and nicotine salts. The high salinity and nicotine salts are challenging to be addressed by traditional treatment and are a severe threat that ought to be overcome. Thus, proper techniques can regenerate the tobacco stalks into reconstituted tobacco flakes used as cigarette filler. The electrodialysis process has been a viable approach to removing the inorganic ingredients in wastewater. We studied concentration, pH, and co-related influences with the nicotine and sugar/nicotine contents on the desalination performance. The results show that the inorganic ions such as Cl−, K+, Ca2+, and Mg2+ ions were successfully removed. When the feed concentration ranges from 3 to 15%, the removal ratio of the K+ ions is higher than Ca2+ and Mg2+ ions. As we reported previously, the K+ and Ca2+ ions are unfavorable for the total particulate matter emission but beneficial to decreasing the HCN delivery in mainstream cigarette smoke. Selective ED is a robust technology to reduce the harmful component delivery in cigarette smoke.
      Citation: Membranes
      PubDate: 2022-06-07
      DOI: 10.3390/membranes12060597
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 598: Membrane and Membrane Bioreactors Applied
           to Health and Life Sciences

    • Authors: Simona Salerno, Enrico Drioli, Loredana De Bartolo
      First page: 598
      Abstract: The interest in membranes and membrane bioreactors for health and life sciences is rapidly growing thanks to their wide applications in advanced therapies and biotechnologies [...]
      Citation: Membranes
      PubDate: 2022-06-09
      DOI: 10.3390/membranes12060598
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 599: Reagent-Free Immobilization of Industrial
           Lipases to Develop Lipolytic Membranes with Self-Cleaning Surfaces

    • Authors: Martin Schmidt, Andrea Prager, Nadja Schönherr, Roger Gläser, Agnes Schulze
      First page: 599
      Abstract: Biocatalytic membrane reactors combine the highly efficient biotransformation capability of enzymes with the selective filtration performance of membrane filters. Common strategies to immobilize enzymes on polymeric membranes are based on chemical coupling reactions. Still, they are associated with drawbacks such as long reaction times, high costs, and the use of potentially toxic or hazardous reagents. In this study, a reagent-free immobilization method based on electron beam irradiation was investigated, which allows much faster, cleaner, and cheaper fabrication of enzyme membrane reactors. Two industrial lipase enzymes were coupled onto a polyvinylidene fluoride (PVDF) flat sheet membrane to create self-cleaning surfaces. The response surface methodology (RSM) in the design-of-experiments approach was applied to investigate the effects of three numerical factors on enzyme activity, yielding a maximum activity of 823 ± 118 U m−2 (enzyme concentration: 8.4 g L−1, impregnation time: 5 min, irradiation dose: 80 kGy). The lipolytic membranes were used in fouling tests with olive oil (1 g L−1 in 2 mM sodium dodecyl sulfate), resulting in 100% regeneration of filtration performance after 3 h of self-cleaning in an aqueous buffer (pH 8, 37 °C). Reusability with three consecutive cycles demonstrates regeneration of 95%. Comprehensive membrane characterization was performed by determining enzyme kinetic parameters, permeance monitoring, X-ray photoelectron spectroscopy, FTIR spectroscopy, scanning electron microscopy, and zeta potential, as well as water contact angle measurements.
      Citation: Membranes
      PubDate: 2022-06-09
      DOI: 10.3390/membranes12060599
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 600: Translocating Peptides of Biomedical
           Interest Obtained from the Spike (S) Glycoprotein of the SARS-CoV-2

    • Authors: Maria C. Henao, Camila Ocasion, Paola Ruiz Puentes, Cristina González-Melo, Valentina Quezada, Javier Cifuentes, Arnovis Yepes, Juan C. Burgos, Juan C. Cruz, Luis H. Reyes
      First page: 600
      Abstract: At the beginning of 2020, the pandemic caused by the SARS-CoV-2 virus led to the fast sequencing of its genome to facilitate molecular engineering strategies to control the pathogen’s spread. The spike (S) glycoprotein has been identified as the leading therapeutic agent due to its role in localizing the ACE2 receptor in the host’s pulmonary cell membrane, binding, and eventually infecting the cells. Due to the difficulty of delivering bioactive molecules to the intracellular space, we hypothesized that the S protein could serve as a source of membrane translocating peptides. AHB-1, AHB-2, and AHB-3 peptides were identified and analyzed on a membrane model of DPPC (dipalmitoylphosphatidylcholine) using molecular dynamics (MD) simulations. An umbrella sampling approach was used to quantify the energy barrier necessary to cross the boundary (13.2 to 34.9 kcal/mol), and a flat-bottom pulling helped to gain a deeper understanding of the membrane’s permeation dynamics. Our studies revealed that the novel peptide AHB-1 exhibited comparable penetration potential of already known potent cell-penetrating peptides (CPPs) such as TP2, Buforin II, and Frenatin 2.3s. Results were confirmed by in vitro analysis of the peptides conjugated to chitosan nanoparticles, demonstrating its ability to reach the cytosol and escape endosomes, while maintaining high biocompatibility levels according to standardized assays.
      Citation: Membranes
      PubDate: 2022-06-10
      DOI: 10.3390/membranes12060600
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 601: Negatively Charged MOF-Based Composite
           Anion Exchange Membrane with High Cation Selectivity and Permeability

    • Authors: Xiaohuan Li, Xiaopeng Chen, Yifeng Wu, Yu Chen, Feng Shao, Jiaxian Song, Shuai Yao, Ru Xia, Jiasheng Qian, Bin Wu, Jibin Miao
      First page: 601
      Abstract: Every metal and metallurgical industry is associated with the generation of wastewater, influencing the living and non-living environment, which is alarming to environmentalists. The strict regulations about the dismissal of acid and metal into the environment and the increasing emphasis on the recycling/reuse of these effluents after proper remedy have focused the research community’s curiosity in developing distinctive approaches for the recovery of acid and metals from industrial wastewaters. This study reports the synthesis of UiO-66-(COOH)2 using dual ligand in water as a green solvent. Then, the prepared MOF nanoparticles were introduced into the DMAM quaternized QPPO matrix through a straightforward blending approach. Four defect-free UiO-66-(COOH)2/QPPO MMMs were prepared with four different MOF structures. The BET characterization of UiO-66-(COOH)2 nanoparticles with a highly crystalline structure and sub-nanometer pore size (~7 Å) was confirmed by XRD. Because of the introduction of MOF nanoparticles with an electrostatic interaction and pore size screening effect, a separation coefficient (SHCl/FeCl2) of 565 and UHCl of 0.0089 m·h−1 for U-C(60)/QPPO were perceived when the loading dosage of the MOF content was 10 wt%. The obtained results showed that the prepared defect-free MOF membrane has broad prospects in acid recovery applications.
      Citation: Membranes
      PubDate: 2022-06-10
      DOI: 10.3390/membranes12060601
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 602: A New Method Based on a Zero Gap
           Electrolysis Cell for Producing Bleach: Concept Validation

    • Authors: Rihab Belhadj Ammar, Takoua Ounissi, Lassaad Baklouti, Christian Larchet, Lasâad Dammak, Arthur Mofakhami, Emna Selmane Belhadj Hmida
      First page: 602
      Abstract: Commercial bleach (3.6 wt% active chlorine) is prepared by diluting highly concentrated industrial solutions of sodium hypochlorite (about 13 wt% active chlorine) obtained mainly by bubbling chlorine gas into dilute caustic soda. The chlorine and soda used are often obtained by electrolyzing a sodium chloride solution in two-compartment cells (chlorine-soda processes). On a smaller scale, small units used for swimming pool water treatment, for example, allow the production of low-concentration bleach (0.3 to 1 wt% active chlorine) by use of a direct electrolysis of sodium chloride brine. The oxidation and degradation reaction of hypochlorite ion (ClO−) at the anode is the major limiting element of this two-compartment process. In this study, we have developed a new process to obtain higher levels of active chlorine up to 3.6%, or 12° chlorometric degree. For this purpose, we tested a device consisting of a zero-gap electrolysis cell, with three compartments separated by a pair of membranes that can be porous or ion-exchange. The idea is to generate in the anode compartment hypochlorous acid (HClO) at high levels by continuously adjusting its pH to a value between 4.5 and 5.5. In the cathodic compartment, caustic soda is obtained, while the central compartment is supplied with brine. The hypochlorous acid solution is then neutralized with a concentrated solution of NaOH to obtain bleach. In this work, we studied several membrane couples that allowed us to optimize the operating conditions and to obtain bleach with contents close to 1.8 wt% of active chlorine. The results obtained according to the properties of the membranes, their durability, and the imposed electrochemical conditions were discussed.
      Citation: Membranes
      PubDate: 2022-06-10
      DOI: 10.3390/membranes12060602
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 603: Determination of Compressibility and
           Relaxation Behavior of Yeast Cell Sediments by Analytical Centrifugation
           and Comparison with Deposit Formation on Membrane Surfaces

    • Authors: Maria E. Weinberger, Ulrich Kulozik
      First page: 603
      Abstract: Separation of cells from produced biomolecules is a challenging task in many biotechnological downstream operations due to deposit formation of the retained cells, affecting permeation of the target product. Compression and relaxation behavior of cell deposits formed during filtration are important factors affecting operational performance. The determination of these factors by flux or pressure stepping experiments is time- and labor-intensive. In this work, we propose a screening method by analytical centrifugation, which is capable of detecting small differences in compression and relaxation behavior induced by milieu changes, using a model system comprised of washed and unwashed yeast cells in the presence or absence of bovine serum albumin as a model target protein. The main effects observed were firstly the impact of pH value, affecting interaction of bovine serum albumin and yeast cells especially close to the isoelectric point, and secondly the effect of washing the yeast cells prior to analysis, where the presence of extracellular polymeric substances led to higher compressibility of the deposited cells. By comparing and validating the obtained results with dead-end filtration trials, the stabilizing role of bovine serum albumin in deposits formed at low pH values due to interactions with the yeast cells was underlined.
      Citation: Membranes
      PubDate: 2022-06-10
      DOI: 10.3390/membranes12060603
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 604: Preparation of Alumina-Sphere-Supported
           Potassium Chabazite Zeolite Membrane with Excellent Potassium Extraction
           Performance at Room Temperature

    • Authors: Jie Ouyang, Heng Wei, Jin Hou
      First page: 604
      Abstract: In this paper, a potassium chabazite (KCHA) zeolite membrane was prepared by coating KCHA zeolite on the surface of a porous alumina sphere. The performance of the KCHA zeolite membrane in extracting potassium from seawater and sea bittern at room temperature was studied in detail. The XRD results show that the prepared KCHA zeolite was a KCHA membrane. The EDS test indicated that the potassium content of the KCHA zeolite membrane reached a value of 18.33 wt.%. The morphology of the KCHA zeolite grown on the surface of the alumina sphere was similar to a sphere, and it had good symmetry. The potassium ion-exchange capacities of the KCHA zeolite membrane reached 32 mg/g in seawater and 77 mg/g in sea bittern at room temperature. Ion exchange between the ammonium ions and potassium ions in the KCHA zeolite membrane could be completed in a short time at room temperature. The KCHA zeolite membrane was proven to have good reusability in seawater and sea bittern. The selective ion-exchange mechanism of the KCHA zeolite membrane was controlled by a specific K+ ion memory.
      Citation: Membranes
      PubDate: 2022-06-10
      DOI: 10.3390/membranes12060604
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 605: Platelet-Membrane-Encapsulated Carvedilol
           with Improved Targeting Ability for Relieving Myocardial
           Ischemia–Reperfusion Injury

    • Authors: Tingting Zhou, Xuechao Yang, Tianyi Wang, Mingming Xu, Zhanghao Huang, Runze Yu, Yi Jiang, Youlang Zhou, Jiahai Shi
      First page: 605
      Abstract: In recent years, cell membrane drug delivery systems have received increasing attention. However, drug-loaded membrane delivery systems targeting therapy in myocardial ischemia–reperfusion injury (MIRI) have been relatively rarely studied. The purpose of this study was to explore the protective effect of platelet-membrane-encapsulated Carvedilol on MIRI. We extracted platelets from the blood of adult SD rats and prepared platelet membrane vesicles (PMVs). Carvedilol, a nonselective β-blocker, was encapsulated into the PMVs. In order to determine the best encapsulation rate and drug-loading rate, three different concentrations of Carvedilol in low, medium, and high amounts were fused to the PMVs in different volume ratios (drugs/PMVs at 2:1, 1:1, 1:2, and 4:1) for determining the optimum concentration and volume ratio. By comparing other delivery methods, including abdominal injection and intravenous administration, the efficacy of PMVs-encapsulated drug-targeted delivery treatment was observed. The PMVs have the ability to target ischemic-damaged myocardial tissue, and the concentration and volume ratio at the optimum encapsulation rate and the drug-loading rate are 0.5 mg and 1:1. We verified that PMVs@Carvedilol had better therapeutic effects compared to other treatment groups, and immunofluorescence observation showed a significant improvement in the apoptosis indicators and infarction area of myocardial cells. Targeted administration of PMVs@Carvedilol may be a promising treatment for myocardial reperfusion injury, as it significantly improves postinjury cardiac function and increases drug utilization compared to other delivery methods.
      Citation: Membranes
      PubDate: 2022-06-10
      DOI: 10.3390/membranes12060605
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 606: Plasma Membrane-Associated Proteins
           Identified in Arabidopsis Wild Type, lbr2-2 and bak1-4 Mutants Treated
           with LPSs from Pseudomonas syringae and Xanthomonas campestris

    • Authors: Benedict C. Offor, Msizi I. Mhlongo, Ian A. Dubery, Lizelle A. Piater
      First page: 606
      Abstract: Plants recognise bacterial microbe-associated molecular patterns (MAMPs) from the environment via plasma membrane (PM)-localised pattern recognition receptor(s) (PRRs). Lipopolysaccharides (LPSs) are known as MAMPs from gram-negative bacteria that are most likely recognised by PRRs and trigger defence responses in plants. The Arabidopsis PRR(s) and/or co-receptor(s) complex for LPS and the associated defence signalling remains elusive. As such, proteomic identification of LPS receptors and/or co-receptor complexes will help to elucidate the molecular mechanisms that underly LPS perception and defence signalling in plants. The Arabidopsis LPS-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI)-related-2 (LBR2) have been shown to recognise LPS and trigger defence responses while brassinosteroid insensitive 1 (BRI1)-associated receptor kinase 1 (BAK1) acts as a co-receptor for several PRRs. In this study, Arabidopsis wild type (WT) and T-DNA knock out mutants (lbr2-2 and bak1-4) were treated with LPS chemotypes from Pseudomonas syringae pv. tomato DC3000 (Pst) and Xanthomonas campestris pv. campestris 8004 (Xcc) over a 24 h period. The PM-associated protein fractions were separated by liquid chromatography and analysed by tandem mass spectrometry (LC-MS/MS) followed by data analysis using ByonicTM software. Using Gene Ontology (GO) for molecular function and biological processes, significant LPS-responsive proteins were grouped according to defence and stress response, perception and signalling, membrane transport and trafficking, metabolic processes and others. Venn diagrams demarcated the MAMP-responsive proteins that were common and distinct to the WT and mutant lines following treatment with the two LPS chemotypes, suggesting contributions from differential LPS sub-structural moieties and involvement of LBR2 and BAK1 in the LPS-induced MAMP-triggered immunity (MTI). Moreover, the identification of RLKs and RLPs that participate in other bacterial and fungal MAMP signalling proposes the involvement of more than one receptor and/or co-receptor for LPS perception as well as signalling in Arabidopsis defence responses.
      Citation: Membranes
      PubDate: 2022-06-10
      DOI: 10.3390/membranes12060606
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 607: Enhancing Performance of Thin-Film
           Nanocomposite Membranes by Embedding in Situ Silica Nanoparticles

    • Authors: Manuel Reyes De Guzman, Micah Belle Marie Yap Ang, Kai-Ting Hsu, Min-Yi Chu, Jeremiah C. Millare, Shu-Hsien Huang, Hui-An Tsai, Kueir-Rarn Lee
      First page: 607
      Abstract: In this work, silica nanoparticles were produced in situ, to be embedded eventually in the polyamide layer formed during interfacial polymerization for fabricating thin-film nanocomposite membranes with enhanced performance for dehydrating isopropanol solution. The nanoparticles were synthesized through a sol-gel reaction between 3-aminopropyltrimethoxysilane (APTMOS) and 1,3-cyclohexanediamine (CHDA). Two monomers—CHDA (with APTMOS) and trimesoyl chloride—were reacted on a hydrolyzed polyacrylonitrile (hPAN) support. To obtain optimum fabricating conditions, the ratio of APTMOS to CHDA and reaction time were varied. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) were used to illustrate the change in morphology as a result of embedding silica nanoparticles. The optimal conditions for preparing the nanocomposite membrane turned out to be 0.15 (g/g) APTMOS/CHDA and 60 min mixing of APTMOS and CHDA, leading to the following membrane performance: flux = 1071 ± 79 g∙m−2∙h−1, water concentration in permeate = 97.34 ± 0.61%, and separation factor = 85.39. A stable performance was shown by the membrane under different operating conditions, where the water concentration in permeate was more than 90 wt%. Therefore, the embedment of silica nanoparticles generated in situ enhanced the separation efficiency of the membrane.
      Citation: Membranes
      PubDate: 2022-06-11
      DOI: 10.3390/membranes12060607
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 608: Thermo-Statistical Effects of Inclusions on
           Vesicles: Division into Multispheres and Polyhedral Deformation

    • Authors: Yuno Natsume
      First page: 608
      Abstract: The construction of simple cellular models has attracted much attention as a way to explore the origin of life or elucidate the mechanisms of cell division. In the absence of complex regulatory systems, some bacteria spontaneously divide through thermostatistically elucidated mechanisms, and incorporating these simple physical principles could help to construct primitive or artificial cells. Because thermodynamic interactions play an essential role in such mechanisms, this review discusses the thermodynamic aspects of spontaneous division models of vesicles that contain a high density of inclusions, with their membrane serving as a boundary. Vesicles with highly dense inclusions are deformed according to the volume-to-area ratio. The phase separation of beads at specific intermediate volume fractions and the associated polyhedral deformation of the membrane are considered in relation to the Alder transition. Current advances in the development of a membrane-growth vesicular model are summarized. The thermostatistical understanding of these mechanisms could become a cornerstone for the construction of vesicular models that display spontaneous cell division.
      Citation: Membranes
      PubDate: 2022-06-11
      DOI: 10.3390/membranes12060608
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 609: Effect of Electrode Type on Electrospun
           Membrane Morphology Using Low-Concentration PVA Solutions

    • Authors: Zane Zelca, Andres Krumme, Silvija Kukle, Mihkel Viirsalu, Laimdota Vilcena
      First page: 609
      Abstract: Electrospun polymer nanofiber materials have been studied as basic materials for various applications. Depending on the intended use of the fibers, their morphology can be adjusted by changing the technological parameters, the properties of the spinning solutions, and the combinations of composition. The aim of the research was to evaluate the effect of electrode type, spinning parameters, polymer molecular weight, and solution concentration on membranes morphology. The main priority was to obtain the smallest possible fiber diameters and homogeneous electrospun membranes. As a result, five electrode types were selected, the lowest PVA solution concentration for stable spinning process was detected, spinning parameters for homogenous fibers were obtained, and the morphology of electrospun fiber membranes was analyzed. Viscosity, conductivity, pH, and density were evaluated for PVA polymers with five different molecular weights (30–145 kDa) and three concentration solutions (6, 8, and 10 wt.%). The membrane defects and fiber diameters were compared as a function of molecular weight and electrode type. The minimum concentration of PVA in the solution allowed more additives to be added to the solution, resulting in thinner diameters and a higher concentration of the additive in the membranes. The molecular weight, concentration, and electrode significantly affected the fiber diameters and the overall quality of the membrane.
      Citation: Membranes
      PubDate: 2022-06-11
      DOI: 10.3390/membranes12060609
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 610: Pilot-Scale Selective Electrodialysis for
           the Separation of Chloride and Sulphate from High-Salinity Wastewater

    • Authors: Fuqin Li, Yanfu Guo, Shaozhou Wang
      First page: 610
      Abstract: The separation of chloride and sulphate is important for the treatment of high salt wastewater, and monovalent selective electrodialysis (MSED) has advantages in terms of energy consumption and pre-treatment costs compared to nanofiltration salt separation. Most of the research on monovalent anion-selective membranes (MASM) is still on a laboratory scale due to the preparation process, cost, and other reasons. In this study, a low-cost, easy-to-operate modification scheme was used to prepare MASM, which was applied to assemble a pilot-scale electrodialysis device to treat reverse osmosis concentrated water with a salt content of 4% to 5%. The results indicate that the optimum operating conditions for the device are: 250 L/h influent flow rate for the concentration and dilute compartments, 350 L/h influent flow rate for the electrode compartment and a constant voltage of 20 V. The separation effect of the pilot electrodialysis plant at optimal operating conditions was: the Cl− and SO42− transmission rates of 80% and 2.54% respectively, the separation efficiency (S) of 93.85% and the Energy consumption per unit of NaCl (ENaCl) of 0.344 kWh/kg. The analysis of the variation of the three parameters of selective separation performance during electrodialysis indicates that the separation efficiency (S) is a suitable parameter for measuring the selective separation performance of the device compared to the monovalent selectivity coefficient (PSO42−Cl−).
      Citation: Membranes
      PubDate: 2022-06-11
      DOI: 10.3390/membranes12060610
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 611: Chemical Vapour Deposition
           Graphene–PMMA Nanolaminates for Flexible Gas Barrier

    • Authors: Antonio Baldanza, Maria Giovanna Pastore Carbone, Cosimo Brondi, Anastasios C. Manikas, Giuseppe Mensitieri, Christos Pavlou, Giuseppe Scherillo, Costas Galiotis
      First page: 611
      Abstract: Successful ways of fully exploiting the excellent structural and multifunctional performance of graphene and related materials are of great scientific and technological interest. New opportunities are provided by the fabrication of a novel class of nanocomposites with a nanolaminate architecture. In this work, by using the iterative lift-off/float-on process combined with wet depositions, we incorporated cm-size graphene monolayers produced via Chemical Vapour Deposition into a poly (methyl methacrylate) (PMMA) matrix with a controlled, alternate-layered structure. The produced nanolaminate shows a significant improvement in mechanical properties, with enhanced stiffness, strength and toughness, with the addition of only 0.06 vol% of graphene. Furthermore, oxygen and carbon dioxide permeability measurements performed at different relative humidity levels, reveal that the addition of graphene leads to significant reduction of permeability, compared to neat PMMA. Overall, we demonstrate that the produced graphene–PMMA nanolaminate surpasses, in terms of gas barrier properties, the traditional discontinuous graphene–particle composites with a similar filler content. Moreover, we found that the gas permeability through the nanocomposites departs from a monotonic decrease as a function of relative humidity, which is instead evident in the case of the pure PMMA nanolaminate. This work suggests the possible use of Chemical Vapour Deposition graphene–polymer nanolaminates as a flexible gas barrier, thus enlarging the spectrum of applications for this novel material.
      Citation: Membranes
      PubDate: 2022-06-12
      DOI: 10.3390/membranes12060611
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 612: Light Isotope Separation through the
           Compound Membrane of Graphdiyne

    • Authors: Valentina A. Poteryaeva, Michael A. Bubenchikov, Alexey M. Bubenchikov
      First page: 612
      Abstract: The separation of isotopes of one substance is possible within the framework of the quantum mechanical model. The tunneling effect allows atoms and molecules to overcome the potential barrier with a nonzero probability. The membranes of two monoatomic layers enhance the differences in the components’ passage through the membrane, thereby providing a high separation degree of mixtures. The probability of overcoming the potential barrier by particles is found from the solving of the Schrödinger integral equation. Hermite polynomials are used to expand all the terms of the Schrödinger integral equation in a series to get a wave function. A two-layer graphdiyne membrane is used to separate the mixture.
      Citation: Membranes
      PubDate: 2022-06-13
      DOI: 10.3390/membranes12060612
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 613: Assessment of Processes to Increase the
           Useful Life and the Reuse of Reverse Osmosis Elements in Cape Verde and

    • Authors: Tomás Tavares, Jorge Tavares, Federico A. León-Zerpa, Baltasar Peñate-Suárez, Alejandro Ramos-Martín
      First page: 613
      Abstract: Reverse osmosis membranes could be reused in the same or another desalination plant by replacing the membranes in the dirtiest first positions with those in the least damaged last positions, also changing the best first stage membranes to the second and vice versa. The useful life of these membranes could be extended by chemical cleaning and giving them a second life in tertiary treatment plants, as well as reusing them in industrial processes where special reverse osmosis membranes are used and degrade rapidly, in processes with leachates from landfill waste, and also an interesting option is the oxidation of reverse osmosis elements to obtain nanofiltration, ultrafiltration or microfiltration membranes for the elimination of physical dirt. The main categories of recycling by thermal processing commonly used in the industry include incineration and pyrolysis to produce energy, gas and fuel. These processes can be applied to mixed plastic waste, such as the combination of materials used in the manufacture of reverse osmosis membranes. Recycling of reverse osmosis elements from desalination plants is shown to be an opportunity, and pioneering initiatives are already underway in Europe. Energy recovery via incineration is feasible but is not considered in line with the environmental, social and political problems it may generate. However, the recycling of reverse osmosis elements via the pyrolytic industry for fuel production can be centralized in a new industry already planned in the Macaronesia area, and all obsolete osmosis membranes can be sent there. This is a technically and economically viable business opportunity with a promising future in today’s recycling market, as discussed in the article.
      Citation: Membranes
      PubDate: 2022-06-13
      DOI: 10.3390/membranes12060613
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 614: Sensitivity of Material, Microstructure and
           Operational Parameters on the Performance of Asymmetric Oxygen Transport
           Membranes: Guidance from Modeling

    • Authors: Kai Wilkner, Robert Mücke, Stefan Baumann, Wilhelm Albert Meulenberg, Olivier Guillon
      First page: 614
      Abstract: Oxygen transport membranes can enable a wide range of efficient energy and industrial applications. One goal of development is to maximize the performance by the improvement of the material, microstructural properties and operational conditions. However, the complexity of the transportation processes taking place in such commonly asymmetric membranes impedes the identification of the parameters to improve them. In this work, we present a sensitivity study that allows identification of these parameters. It is based on a 1D transport model that includes surface exchange, ionic and electronic transport inside the dense membrane, as well as binary diffusion, Knudsen diffusion and viscous flux inside the porous support. A support limitation factor is defined and its dependency on the membrane conductivity is shown. For materials with very high ambipolar conductivity the transport is limited by the porous support (in particular the pore tortuosity), whereas for materials with low ambipolar conductivity the transport is limited by the dense membrane. Moreover, the influence of total pressure and related oxygen partial pressures in the gas phase at the membrane’s surfaces was revealed to be significant, which has been neglected so far in permeation test setups reported in the literature. In addition, the accuracy of each parameter’s experimental determination is discussed. The model is well-suited to guiding experimentalists in developing high-performance gas separation membranes.
      Citation: Membranes
      PubDate: 2022-06-13
      DOI: 10.3390/membranes12060614
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 615: Characterization and Interaction with
           Biomembrane Model of Benzo[k,l]xanthene Lignan Loaded Solid Lipid

    • Authors: Cristina Torrisi, Nunzio Cardullo, Vera Muccilli, Corrado Tringali, Francesco Castelli, Maria Grazia Sarpietro
      First page: 615
      Abstract: Benzo[k,l]xanthene lignans are a group of rare natural products belonging to the class of polyphenols with promising biological activities and are studied as potential chemotherapeutic agents. The lipophilic character of a xanthene core makes these molecules difficult to be used in an aqueous medium, limiting their employment in studies for pharmaceutical applications. To overcome this problem, a drug-delivery system which is able to improve the stability and bioavailability of the compound can be used. In this study, a bioactive benzoxanthene lignan (BXL) has been included in SLN. Unloaded and BXL-loaded SLN have been prepared using the Phase Inversion Temperature method and characterized in terms of size, zeta potential, entrapment efficiency and stability. Differential scanning calorimetry was used to evaluate the thermotropic behavior and ability of SLN to act as carriers for BXL. A biomembrane model, represented by multilamellar vesicles, was used to simulate the interaction of the SLN with the cellular membrane. Unloaded and loaded SLN were incubated with the MLV, and their interactions were evaluated through variations in their calorimetric curves. The results obtained suggest that SLN could be used as a delivery system for BXL.
      Citation: Membranes
      PubDate: 2022-06-13
      DOI: 10.3390/membranes12060615
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 616: Is Lipid Specificity Key to the Potential
           Antiviral Activity of Mouthwash Reagent Chlorhexidine against

    • Authors: Arun K. Rathod, Chetan S. Poojari, Moutusi Manna
      First page: 616
      Abstract: Chlorhexidine (CHX), a popular antibacterial drug, is widely used for oral health. Emerging pieces of evidence suggest that commercially available chlorhexidine mouthwash formulations are effective in suppressing the spread of SARS-CoV-2, possibly through destabilization of the viral lipid envelope. CHX is known for its membrane-active properties; however, the molecular mechanism revealing how it damages the viral lipid envelope is yet to be understood. Here we used extensive conventional and umbrella sampling simulations to quantify the effects of CHX on model membranes mimicking the composition of the SARS-CoV-2 outer lipid membrane as well as the host plasma membrane. Our results show that the lipid composition and physical properties of the membrane play an important role in binding and insertion, with CHX binding favorably to the viral membrane over the plasma membrane. Among the simulated lipids, CHX preferentially binds to anionic lipids, PS and PI, which are more concentrated in the viral membrane. The deeper and stable binding of CHX to the viral membrane results in more pronounced swelling of the membrane laterally with a thinning of the bilayer. The overall free energies of pore formation are strongly reduced for the viral membrane compared to the plasma membrane; however, CHX has a larger concentration-dependent effect on free energies of pore formation in the plasma membrane than the viral membrane. The results indicate that CHX is less toxic to the human plasma membrane at low concentrations. Our simulations reveal that CHX facilitates pore formation by the combination of thinning the membrane and accumulation at the water defect. This study provides insights into the mechanism underlying the anti-SARS-CoV-2 potency of CHX, supporting its potential for application as an effective and safe oral rinse agent for preventing viral transmission.
      Citation: Membranes
      PubDate: 2022-06-14
      DOI: 10.3390/membranes12060616
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 617: Palladium Membrane with High Density of
           Large-Angle Grain Boundaries to Promote Hydrogen Diffusivity

    • Authors: Efi Hadjixenophontos, Masoud Mahmoudizadeh, Michael Rubin, Dirk Ullmer, Fatemeh Razmjooei, Alexander C. Hanf, Jan Brien, Roland Dittmeyer, Asif Ansar
      First page: 617
      Abstract: A higher density of large-angle grain boundaries in palladium membranes promotes hydrogen diffusion whereas small-angle grain boundaries suppress it. In this paper, the microstructure formation in 10 µm thick palladium membranes is tuned to achieve a submicronic grain size above 100 nm with a high density of large-angle grain boundaries. Moreover, changes in the grain boundaries’ structure is investigated after exposure to hydrogen at 300 and 500 °C. To attain large-angle grain boundaries in Pd, the coating was performed on yttria-stabilized zirconia/porous Crofer 22 APU substrates (intended for use later in an ultracompact membrane reactor). Two techniques of plasma sprayings were used: suspension plasma spraying using liquid nano-sized powder suspension and vacuum plasma spraying using microsized powder as feedstock. By controlling the process parameters in these two techniques, membranes with a comparable density of large-angle grain boundaries could be developed despite the differences in the fabrication methods and feedstocks. Analyses showed that a randomly oriented submicronic structure could be attained with a very similar grain sizes between 100 and 500 nm which could enhance hydrogen permeation. Exposure to hydrogen for 72 h at high temperatures revealed that the samples maintained their large-angle grain boundaries despite the increase in average grain size to around 536 and 720 nm for vacuum plasma spraying and suspension plasma spraying, respectively.
      Citation: Membranes
      PubDate: 2022-06-14
      DOI: 10.3390/membranes12060617
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 618: Extracellular Particles as Carriers of
           Cholesterol Not Associated with Lipoproteins

    • Authors: Sergey Landa, Nicolay Verlov, Natalia Fedorova, Mikhail Filatov, Rimma Pantina, Vladimir Burdakov, Elena Varfolomeeva, Vladimir Emanuel
      First page: 618
      Abstract: Exosomes and exomeres are the smallest microparticles ranging from 20 to 130 nm in diameter. They are found in almost all biological fluids. Exosomes and exomeres are of considerable interest since they can be involved in intercellular signaling and are biological markers of the state of cells, which can be used for diagnostics. The nomenclature of exosomes remains poorly developed. Most researchers try to classify them based on the mode of formation, physicochemical characteristics, and the presence of tetrasporin markers CD9, CD63, and CD81. The data presented in this work show that although exomeres carry tetrasporin biomarkers, they differ from exosomes strongly in lipid composition, especially in cholesterol content. The production of exomeres by cells is associated with the synthesis of cholesterol in cells and is expressed or suppressed by regulators of the synthesis of mevalonate, an intermediate product of cholesterol metabolism. In addition, the work shows that the concentration of extracellular particles in the body correlates with the concentration of cholesterol in the plasma, but weakly correlates with the concentration of cholesterol in lipoproteins. This suggests that not all plasma cholesterol is associated with lipoproteins, as previously thought.
      Citation: Membranes
      PubDate: 2022-06-14
      DOI: 10.3390/membranes12060618
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 619: Notes on the Treatment of Charged Particles
           for Studying Cyclotide/Membrane Interactions with Dissipative Particle

    • Authors: Felix Bänsch, Christoph Steinbeck, Achim Zielesny
      First page: 619
      Abstract: Different charge treatment approaches are examined for cyclotide-induced plasma membrane disruption by lipid extraction studied with dissipative particle dynamics. A pure Coulomb approach with truncated forces tuned to avoid individual strong ion pairing still reveals hidden statistical pairing effects that may lead to artificial membrane stabilization or distortion of cyclotide activity depending on the cyclotide’s charge state. While qualitative behavior is not affected in an apparent manner, more sensitive quantitative evaluations can be systematically biased. The findings suggest a charge smearing of point charges by an adequate charge distribution. For large mesoscopic simulation boxes, approximations for the Ewald sum to account for mirror charges due to periodic boundary conditions are of negligible influence.
      Citation: Membranes
      PubDate: 2022-06-14
      DOI: 10.3390/membranes12060619
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 620: Electromembrane Extraction of Posaconazole
           for Matrix-Assisted Laser Desorption/Ionization Mass Spectrometric

    • Authors: Chi-Sheng Chen, Wen-Chi Chen, Sarah Y. Chang
      First page: 620
      Abstract: A new mode of electromembrane extraction (EME) has been developed for detection via matrix-assisted laser desorption/ionization mass spectrometry (MALDI/MS). Posaconazole, extracted from 8 mL of a 10 mM trifluoroacetic acid solution onto a thin polyvinylidene difluoride (PVDF) membrane, was used as a model analyte. The transport was forced by an electrical potential difference between two electrodes inside the lumen of a hollow fiber and glass tube. Under an application of 80 V, cationic posaconazole in the sample solution moved toward the negative electrode inside the glass tube and was trapped by the PVDF membrane on the side. After 15 min of extraction, 3 μL of α-cyano-4-hydroxycinnamic acid (CHCA) solution was applied on top of the membrane, which was then analyzed by MALDI/MS. Under optimal extraction conditions, the calibration curve of posaconazole was linear over a concentration range of 0.10–100.00 nM. The limit of detection (LOD) at a signal-to-noise ratio of 3 was 0.03 nM with an enhancement factor of 138 for posaconazole. The application of this method to the determination of posaconazole in human serum samples was also successfully demonstrated.
      Citation: Membranes
      PubDate: 2022-06-14
      DOI: 10.3390/membranes12060620
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 621: Carbon Nanotube Enhanced Filtration and
           Dewatering of Kerosene

    • Authors: Sumona Paul, Mitun Chandra Bhoumick, Sagar Roy, Somenath Mitra
      First page: 621
      Abstract: Current approaches to dewatering aviation fuel such as kerosene are adsorption by activated charcoal, gravity separation, etc. The objective of this work is to develop and demonstrate the filtration and dewatering of kerosene using a carbon nanotube immobilised membrane (CNIM). Highly hydrophobic membranes were prepared by immobilising carbon nanotube (CNTs) over polytetrafluoroethylene (PTFE) and polyvinylidene difluoride (PVDF) microfiltration membrane for the dewatering of ppm level water from kerosene. The effects of different CNT concentrations on membrane morphology, hydrophobicity, porosity, and permeability were characterised. After immobilising CNT into membranes, the contact angle increased by 9%, 16%, and 43% compared to unmodified 0.1 μm PTFE, 0.22 μm PTFE and 0.22 μm PVDF membranes, respectively. The CNIM showed remarkable separation efficiency for the fuel-water system. The micro/nano water droplets coalesced on the CNT surface to form larger diameters of water droplets detached from the membrane surface, leading to enhanced water rejection. In general, the water rejection increased with the amount of CNT immobilised while the effective surface porosity over pore length and flux decreased. PTFE base membrane showed better performance compared to the PVDF substrate. The CNIMs were fabricated with 0.1 and 0.22 μm PTFE at an optimised CNT loading of 3 and 6 wt.%, and the water rejection was 99.97% and 97.27%, respectively, while the kerosene fluxes were 43.22 kg/m2·h and 55.44 kg/m2·h respectively.
      Citation: Membranes
      PubDate: 2022-06-15
      DOI: 10.3390/membranes12060621
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 622: Membranes for Gas Separation and
           Purification Processes

    • Authors: Chong Yang Chuah
      First page: 622
      Abstract: This Special Issue, entitled “Membranes for Gas Separation and Purification Processes”, was introduced to discuss the recent progress in the development of membranes for gas separation and purification [...]
      Citation: Membranes
      PubDate: 2022-06-15
      DOI: 10.3390/membranes12060622
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 623: Novel Membranes for Environmental

    • Authors: Dong Zou, Zhaoxiang Zhong
      First page: 623
      Abstract: Membrane-based separations for water purification and gas separation have been applied extensively to address the global challenges of water scarcity and the pollution of aquatic and air environments [...]
      Citation: Membranes
      PubDate: 2022-06-15
      DOI: 10.3390/membranes12060623
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 624: Semi-Quantitative Evaluation of
           Asymmetricity of Dialysis Membrane Using Forward and Backward

    • Authors: Akihiro C. Yamashita, Toshiki Kakee, Takahisa Ono, Jun Motegi, Satoru Yamaguchi, Takashi Sunohara
      First page: 624
      Abstract: Performance of the dialysis membrane is strongly dependent upon the physicochemical structure of the membrane. The objective of this study is to devise a new in vitro evaluation technique to quantify the physicochemical structures of the membrane. Three commercial dialyzers with cellulose triacetate (CTA), asymmetric CTA (termed ATA®), and polyether sulfone (PES) membranes (Nipro Co., Osaka, Japan) were employed for investigation. Forward and backward ultrafiltration experiments were performed separately with aqueous vitamin B12 (MW 1355), α-chymotrypsin (MW 25,000), albumin (MW 66,000) and dextran solutions, introducing the test solution inside or outside the hollow fiber (HF), respectively. Sieving coefficients (s.c.) for these solutes were measured under the test solution flow rate of 200 mL/min and the ultrafiltration rate of 10 mL/min at 310 K, according to the guidelines provided by Japanese academic societies. We defined the ratio of s.c. in the backward ultrafiltration to that in the forward ultrafiltration and termed it the index for asymmetricity (IA). The IA values were unity for vitamin B12 and α-chymotrypsin in all three of the dialyzers. The IA values for albumin, however, were 1.0 in CTA, 1.9 in ATA®, and 3.9 in PES membranes, respectively, which corresponded well with the fact that CTA is homogeneous, whereas ATA® and PES are asymmetrical in structure. Moreover, the asymmetricity of ATA® and PES may be different by twofold. This fact was verified in continuous basis by employing dextran solution before and after being fouled with albumin. These findings may contribute to the development of a novel membrane for improved success of dialysis therapy.
      Citation: Membranes
      PubDate: 2022-06-15
      DOI: 10.3390/membranes12060624
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 625: Mitochondrial Membranes and Mitochondrial
           Genome: Interactions and Clinical Syndromes

    • Authors: Mohammed Almannai, Azza Salah, Ayman W. El-Hattab
      First page: 625
      Abstract: Mitochondria are surrounded by two membranes; the outer mitochondrial membrane and the inner mitochondrial membrane. They are unique organelles since they have their own DNA, the mitochondrial DNA (mtDNA), which is replicated continuously. Mitochondrial membranes have direct interaction with mtDNA and are therefore involved in organization of the mitochondrial genome. They also play essential roles in mitochondrial dynamics and the supply of nucleotides for mtDNA synthesis. In this review, we will discuss how the mitochondrial membranes interact with mtDNA and how this interaction is essential for mtDNA maintenance. We will review different mtDNA maintenance disorders that result from defects in this crucial interaction. Finally, we will review therapeutic approaches relevant to defects in mitochondrial membranes.
      Citation: Membranes
      PubDate: 2022-06-15
      DOI: 10.3390/membranes12060625
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 626: Antifouling Conductive Composite Membrane
           with Reversible Wettability for Wastewater Treatment

    • Authors: Yi Li, Ruonan Gao, Jianwen Zhang, Yue Zhang, Shuai Liang
      First page: 626
      Abstract: Membrane fouling severely hinders the sustainable development of membrane separation technology. Membrane wetting property is one of the most important factors dominating the development of membrane fouling. Theoretically, a hydrophilic membrane is expected to be more resistant to fouling during filtration, while a hydrophobic membrane with low surface energy is more advantageous during membrane cleaning. However, conventional membrane materials do not possess the capability to change their wettability on demand. In this study, a stainless steel mesh–sulfosuccinate-doped polypyrrole composite membrane (SSM/PPY(AOT)) was prepared. By applying a negative or positive potential, the surface wettability of the membrane can be switched between hydrophilic and relatively hydrophobic states. Systematic characterizations and a series of filtration experiments were carried out. In the reduction state, the sulfonic acid groups of AOT were more exposed to the membrane surface, rendering the surface more hydrophilic. The fouling filtration experiments verified that the membrane is more resistant to fouling in the hydrophilic state during filtration and easier to clean in the hydrophobic state during membrane cleaning. Furthermore, Ca2+ and Mg2+ could complex with foulants, aggravating membrane fouling. Overall, this study demonstrates the importance of wettability switching in membrane filtration and suggests promising applications of the SSM/PPY(AOT) membrane.
      Citation: Membranes
      PubDate: 2022-06-16
      DOI: 10.3390/membranes12060626
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 627: Thermodynamic Optimization of Ammonia
           Decomposition Solar Heat Absorption System Based on Membrane Reactor

    • Authors: Tianchao Xie, Shaojun Xia, Qinglong Jin
      First page: 627
      Abstract: In this paper, an ammonia decomposition membrane reactor is applied to a solar heat absorption system, and thermodynamic optimization is carried out according to the usage scenarios. First, a model of an ammonia decomposition solar heat absorption system based on the membrane reactor is established by using finite time thermodynamics (FTT) theory. Then, the three-objective optimization with and the four-objective optimization without the constraint of the given heat absorption rate are carried out by using the NSGA-II algorithm. Finally, the optimized performance objectives and the corresponding design parameters are obtained by using the TOPSIS decision method. Compared with the reference system, the TOPSIS optimal solution for the three-objective optimization can reduce the entropy generation rate by 4.8% and increase the thermal efficiency and energy conversion rate by 1.5% and 1.4%, respectively. The optimal solution for the four-objective optimization can reduce the heat absorption rate, entropy generation rate, and energy conversion rate by 15.5%, 14%, and 8.7%, respectively, and improve the thermal efficiency by 15.7%. The results of this paper are useful for the theoretical study and engineering application of ammonia solar heat absorption systems based on membrane reactors.
      Citation: Membranes
      PubDate: 2022-06-16
      DOI: 10.3390/membranes12060627
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 628: Optimal Control of Direct Contact Membrane
           Distillation Operated under Fluctuating Energy Source

    • Authors: Emad Ali
      First page: 628
      Abstract: An optimal control strategy was tested to regulate the flow rate of the cold stream to maximize the time-averaged water production of a laboratory-scale membrane distillation (MD) process. The MD process is operated under fluctuating inlet hot temperatures at a fixed flow rate for the hot stream. The inlet hot temperature fluctuates due to fluctuation in the supplied renewable energy source, such as solar energy. The simulation revealed the possibility of enhancing the average water production by up to 4.2%, by alternating the flow rate of the cold stream relative to a fixed flow rate of the hot stream. The enhancement was limited because, when using a long membrane, the mass flux degrades when the ratio of the cold stream to the hot stream flow rates is either very high or low. By modifying the control strategy to adapt the membrane length in addition to the flow rate of the cold stream, highly improved performance could be obtained. In fact, up to 40% enhancement in the average water production was observed.
      Citation: Membranes
      PubDate: 2022-06-16
      DOI: 10.3390/membranes12060628
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 629: High-Efficiency Water Recovery from Urine
           by Vacuum Membrane Distillation for Space Applications: Water Quality
           Improvement and Operation Stability

    • Authors: Fei Wang, Junfeng Liu, Da Li, Zheng Liu, Jie Zhang, Ping Ding, Guochang Liu, Yujie Feng
      First page: 629
      Abstract: Water recovery by membrane distillation (MD) is an attractive alternative to existing urine treatment systems because it could improve the water recovery rate and reliability in space missions. However, there are few studies of urine MD, particularly on the removal of the remaining contaminants from distillate water and the assessment of its long-term performance. In this study, the influences of various operation parameters on distillate water quality and operation stability were investigated in batch mode. The low pH of feedstock reduced the conductivity and total ammonium nitrogen (TAN) in distillate water because the low pH promoted the ionization of ammonia to ammonium ions. However, the low pH also facilitated the formation of free chlorine hydride, which resulted in the minor deterioration of the conductivity in the distillate due to the increasing volatility of chlorine hydride in the feedstock. Thirty batches of vacuum membrane distillation (VMD) experiments demonstrated that the permeate flux and the distillate water quality slightly decreased due to the small range of membrane wetting but still maintained an over 94.2% and 95.8% removal efficiency of the total organic carbon (TOC) and TAN, and the conductivity was <125 μs cm−1 in the distillate water after 30 test batches. VMD is a feasible option for urine treatment in space missions.
      Citation: Membranes
      PubDate: 2022-06-17
      DOI: 10.3390/membranes12060629
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 630: The Design of Ternary Composite
           Polyurethane Membranes with an Enhanced Photocatalytic Degradation
           Potential for the Removal of Anionic Dyes

    • Authors: Usman Zubair, Muhammad Zahid, Nimra Nadeem, Kainat Ghazal, Huda S. AlSalem, Mona S. Binkadem, Soha T. Al-Goul, Zulfiqar Ahmad Rehan
      First page: 630
      Abstract: Photocatalysis is an efficient and an eco-friendly way to eliminate organic pollutants from wastewater and filtration media. The major dilemma coupled with conventional membrane technology in wastewater remediation is fouling. In this study, the photocatalytic degradation potential of novel thermoplastic polyurethane (TPU) based NiO on aminated graphene oxide (NH2-GO) nanocomposite membranes was explored. The fabrication of TPU-NiO/NH2-GO membranes was achieved by the phase inversion method and analyzed for their performances. The membranes were effectively characterized in terms of surface morphology, functional group, and crystalline phase identification, using scanning electron microscopy, Fourier transformed infrared spectroscopy, and X-ray diffraction analysis, respectively. The prepared materials were investigated in terms of photocatalytic degradation potential against selected pollutants. Approximately 94% dye removal efficiency was observed under optimized conditions (i.e., reaction time = 180 min, pH 3–4, photocatalyst dose = 80 mg/100 mL, and oxidant dose = 10 mM). The optimized membranes possessed effective pure water flux and excellent dye rejection (approximately 94%) under 4 bar pressure. The nickel leaching in the treated wastewater sample was determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). The obtained data was kinetically analyzed using first- and second-order reaction kinetic models. A first-order kinetic study was suited for the present study. Besides, the proposed membranes provided excellent photocatalytic ability up to six reusability cycles. The combination of TPU and NH2-GO provided effective strength to membranes and the immobilization of NiO nanoparticles improved the photocatalytic behavior.
      Citation: Membranes
      PubDate: 2022-06-17
      DOI: 10.3390/membranes12060630
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 631: Ion Separations Based on Spontaneously
           Arising Streaming Potentials in Rotating Isoporous Membranes

    • Authors: Chao Tang, Andriy Yaroshchuk, Merlin L. Bruening
      First page: 631
      Abstract: Highly selective ion separations are vital for producing pure salts, and membrane-based separations are promising alternatives to conventional ion-separation techniques. Our previous work demonstrated that simple pressure-driven flow through negatively charged isoporous membranes can separate Li+ and K+ with selectivities as high as 70 in dilute solutions. The separation mechanism relies on spontaneously arising streaming potentials that induce electromigration, which opposes advection and separates cations based on differences in their electrophoretic mobilities. Although the separation technique is simple, this work shows that high selectivities are possible only with careful consideration of experimental conditions including transmembrane pressure, solution ionic strength, the K+/Li+ ratio in the feed, and the extent of concentration polarization. Separations conducted with a rotating membrane show Li+/K+ selectivities as high as 150 with a 1000 rpm membrane rotation rate, but the selectivity decreases to 1.3 at 95 rpm. These results demonstrate the benefits and necessity of quantitative control of concentration polarization in highly selective separations. Increases in solution ionic strength or the K+/Li+ feed ratio can also decrease selectivities more than an order of magnitude.
      Citation: Membranes
      PubDate: 2022-06-18
      DOI: 10.3390/membranes12060631
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 632: Calculation of Lipophilicity of
           Organophosphate Pesticides Using Density Functional Theory

    • Authors: Kurban E. Magomedov, Ruslan Z. Zeynalov, Sagim I. Suleymanov, Sarizhat D. Tataeva, Viktoriya S. Magomedova
      First page: 632
      Abstract: Higher lipophilicity facilitates the passage of a substance across lipid cell membranes, the blood–brain barrier and protein binding, and may also indicate its toxicity. We proposed eight methods for predicting the lipophilicity of the 22 most commonly used organophosphate pesticides. In this work, to determine the lipophilicity and thermodynamic parameters of the solvation of pesticides, we used methods of density functional theory with various basis sets, as well as modern Grimm methods. The prediction models were evaluated and compared against eight performance statistics, as well as time and RAM used in the calculation. The results show that the PBE-SVP method provided the best of the proposed predictive capabilities. In addition, this method consumes relatively less CPU and RAM resources. These methods make it possible to reliably predict the ability of pesticide molecules to penetrate cell membranes and have a negative effect on cells and the organism as a whole.
      Citation: Membranes
      PubDate: 2022-06-19
      DOI: 10.3390/membranes12060632
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 633: The ESCRT Machinery: Remodeling, Repairing,
           and Sealing Membranes

    • Authors: Yolanda Olmos
      First page: 633
      Abstract: The ESCRT machinery is an evolutionarily conserved membrane remodeling complex that is used by the cell to perform reverse membrane scission in essential processes like protein degradation, cell division, and release of enveloped retroviruses. ESCRT-III, together with the AAA ATPase VPS4, harbors the main remodeling and scission function of the ESCRT machinery, whereas early-acting ESCRTs mainly contribute to protein sorting and ESCRT-III recruitment through association with upstream targeting factors. Here, we review recent advances in our understanding of the molecular mechanisms that underlie membrane constriction and scission by ESCRT-III and describe the involvement of this machinery in the sealing and repairing of damaged cellular membranes, a key function to preserve cellular viability and organellar function.
      Citation: Membranes
      PubDate: 2022-06-19
      DOI: 10.3390/membranes12060633
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 634: Effects of Pressurized Aeration on the
           Biodegradation of Short-Chain Chlorinated Paraffins by Escherichia coli
           Strain 2

    • Authors: Yongxing Qian, Wanling Han, Fuhai Zhou, Bixiao Ji, Huining Zhang, Kefeng Zhang
      First page: 634
      Abstract: Short-chain chlorinated paraffins (SCCPs) were defined as persistent organic pollutants in 2017, and they can migrate and transform in the environment, accumulate in organisms, and amplify through the food chain. Although they pose a serious threat to environmental safety and human health, there are few papers on their removal. The current SCCP removal methods are expensive, require severe operating conditions, involve time-consuming biological treatment, and have poor removal specificities. Therefore, it is important to seek efficient methods to remove SCCPs. In this paper, a pressurized reactor was introduced, and the removal performance of SCCPs by Escherichia coli strain 2 was investigated. The results indicated that moderate pure oxygen pressurization promoted bacterial growth, but when it exceeded 0.15 MPa, the bacterial growth was severely inhibited. When the concentration of SCCPs was 20 mg/L, the removal rate of SCCPs was 85.61% under 0.15 MPa pure oxygen pressurization for 7 days, which was 25% higher than at atmospheric pressure (68.83%). In contrast, the removal rate was only 69.28% under 0.15 MPa air pressure. As the pressure continued to increase, the removal rate of SCCPs decreased significantly. The total amount of extracellular polymeric substances (EPS) increased significantly upon increasing the pressure, and the amount of tightly bound EPS (TB-EPS) was higher than that of loosely bound EPS (LB-EPS). The pressure mainly promoted the secretion of proteins in LB-EPS. Furthermore, an appropriate pure oxygen pressure of 0.15 MPa improved the dehydrogenase activity. The gas chromatography–mass spectrometry (GC–MS) results indicated that the degradation pathway possibly involved the cleavage of the C–Cl bond in SCCPs, which produced Cl−, followed by C–C bond breaking. This process degraded long-chain alkanes into short-chain alkanes. Moreover, the main degradation products detected were 2,4-dimethylheptane (C9H20), 2,5-dimethylheptane (C9H20), and 3,3-dimethylhexane (C8H18).
      Citation: Membranes
      PubDate: 2022-06-19
      DOI: 10.3390/membranes12060634
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 635: Role of Interleukin-6 in the
           Antigen-Specific Mucosal Immunoglobulin A Responses Induced by CpG
           Oligodeoxynucleotide-Loaded Cationic Liposomes

    • Authors: Rui Tada, Emi Honjo, Shoko Muto, Noriko Takayama, Hiroshi Kiyono, Jun Kunisawa, Yoichi Negishi
      First page: 635
      Abstract: An advantage of mucosal vaccines over conventional parenteral vaccines is that they can induce protective immune responses not only at mucosal surfaces but also in systemic compartments. Despite this advantage, few live attenuated or inactivated mucosal vaccines have been developed and applied clinically. We recently showed that the intranasal immunization of ovalbumin (OVA) with class B synthetic oligodeoxynucleotides (ODNs) containing immunostimulatory CpG motif (CpG ODN)-loaded cationic liposomes synergistically exerted both antigen-specific mucosal immunoglobulin A (IgA) and systemic immunoglobulin G (IgG) responses in mice. However, the mechanism underlying the mucosal adjuvant activity of CpG ODN-loaded liposomes remains unknown. In the present study, we showed that the intranasal administration of CpG ODN-loaded cationic liposomes elicited interleukin (IL)-6 release in nasal tissues. Additionally, pre-treatment with an anti-IL-6 receptor (IL-6R) antibody attenuated antigen-specific nasal IgA production but not serum IgG responses. Furthermore, the intranasal administration of OVA and CpG ODN-loaded cationic liposomes increased the number of IgA+/CD138+ plasma cells and IgA+/B220+ B cells in the nasal passages. This increase was markedly suppressed by pre-treatment with anti-IL-6R blocking antibody. In conclusion, IL-6 released by CpG ODN-loaded cationic liposomes at the site of administration may play a role in the induction of antigen-specific IgA responses by promoting differentiation into IgA+ plasma cells for IgA secretion from B cells.
      Citation: Membranes
      PubDate: 2022-06-20
      DOI: 10.3390/membranes12060635
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 636: Characterization of Antimicrobial Composite

    • Authors: Gemilang Lara Utama, Isfari Dinika, Siti Nurmilah, Nanang Masruchin, Bambang Nurhadi, Roostita Lobo Balia
      First page: 636
      Abstract: Antimicrobial composite edible film can be a solution for environmentally friendly food packaging, which can be made from fermented cheese whey containing an antimicrobial agent and cassava peel waste that contains starch. The research aims to determine the formulation of fermented cheese whey and cassava peel waste starch, resulting in an antimicrobial composite edible film with the best physical, mechanical, and water vapour permeability (WVP) properties, as well as with high antimicrobial activity. This research was conducted using experimental methods with nine composite edible film formulation treatments with three replications. Three variations in the fermented cheese whey and cassava peel starch ratio (v/v) (1:3, 1:1, 3:1) were combined with variations in the addition of glycerol (20%, 33%, 45%) (w/w) in the production of the composite edible film. Then, the physical characteristics such as elongation at break, tensile strength, WVP, colour, and antimicrobial effect of its film-forming solution were observed. The results showed that 24 h of whey fermentation with Candida tropicalis resulted in an 18.50 mm inhibition zone towards Pseudomonas aeruginosa. The best characteristic of the film was obtained from the formulation of a whey:starch ratio of 1:3 and 33% glycerol, which resulted in a thickness value of 0.21 mm, elongation at break of 19.62%, tensile strength of 0.81 N/mm2, WVP of 3.41 × 10−10·g/m·s·Pa at a relative humidity (RH) of 100%–35%, and WVP of 9.84 × 10−10·g/m·s·Pa at a RH of 75%–35%, with an antimicrobial activity towards P. aeruginosa of 5.11 mm.
      Citation: Membranes
      PubDate: 2022-06-20
      DOI: 10.3390/membranes12060636
      Issue No: Vol. 12, No. 6 (2022)
  • Membranes, Vol. 12, Pages 541: Influence of Degassing Treatment on the Ink
           Properties and Performance of Proton Exchange Membrane Fuel Cells

    • Authors: Pengcheng Liu, Daijun Yang, Bing Li, Cunman Zhang, Pingwen Ming
      First page: 541
      Abstract: Degradation occurs in catalyst inks because of the catalytic oxidation of the solvent. Identification of the generation process of impurities and their effects on the properties of HSC ink and LSC ink is crucial in mitigating them. In this study, gas chromatography-mass spectrometry (GC-MS) and cyclic voltammetry (CV) showed that oxidation of NPA and EA was the primary cause of impurities such as acetic acid, aldehyde, propionic acid, propanal, 1,1-dipropoxypropane, and propyl propionate. After the degassing treatment, the degradation of the HSC ink was suppressed, and the concentrations of acetic acid, propionic acid, and propyl propionate plummeted from 0.0898 wt.%, 0.00224 wt.%, and 0.00046 wt.% to 0.0025 wt.%, 0.0126 wt.%, and 0.0003 wt.%, respectively. The smaller particle size and higher zeta potential in the degassed HSC ink indicated the higher utilization of Pt, thus leading to optimized mass transfer in the catalyst layer (CL) during working conditions. The electrochemical performance test result shows that the MEA fabricated from the degassed HSC ink had a peak power density of 0.84 W cm−2, which was 0.21 W cm−2 higher than that fabricated from the normal HSC ink. However, the introduction of propionic acid in the LSC ink caused the Marangoni flux to inhibit the coffee ring effect and promote the uniform deposition of the catalyst. The RDE tests indicated that the electrode deposited from the LSC ink with propionic acid possessed a mass activity of 84.4 mA∙mgPt−1, which was higher than the 60.5 mA∙mgPt−1 of the electrode deposited from the normal LSC ink.
      Citation: Membranes
      PubDate: 2022-05-22
      DOI: 10.3390/membranes12050541
      Issue No: Vol. 12, No. 5 (2022)
  • Membranes, Vol. 12, Pages 542: Variables and Mechanisms Affecting
           Electro-Membrane Extraction of Bio-Succinic Acid from Fermentation Broth

    • Authors: Alina Anamaria Malanca, Enrico Mancini, Mohamed Yusuf, Gabriel Kjær Khensir, Seyed Soheil Mansouri, Ioannis V. Skiadas, Hariklia N. Gavala, Manuel Pinelo
      First page: 542
      Abstract: The production of succinic acid from fermentation is a promising approach for obtaining building-block chemicals from renewable sources. However, the limited bio-succinic yield from fermentation and the complexity of purification has been making the bio-succinic acid production not competitive with petroleum-based succinic acid. Membrane electrolysis has been identified to be a promising technology in both production and separation stages of fermentation processes. This work focuses on identifying the key operational parameters affecting the performance of the electrolytic cell for separating succinic acid from fermentation broth through an anionic exchange membrane. Indeed, while efforts are mainly focused on studying the performance of an integrated fermenter-electrolytic cell system, a lack of understanding remains in how to tune the electrolytic cell and which main parameters are involved. The results show that a single electrolytic cell of operating volume 250 mL was able to extract up to 3 g L−1 h−1 of succinic acid. The production of OH− ions by water electrolysis can act as a buffer for the fermenter and it could be tuned as a function of the extraction rate. Furthermore, as the complexity of the solution in terms of the quantity and composition of the ions increased, the energy required for the separation process decreased.
      Citation: Membranes
      PubDate: 2022-05-23
      DOI: 10.3390/membranes12050542
      Issue No: Vol. 12, No. 5 (2022)
  • Membranes, Vol. 12, Pages 543: Water Treatment Process

    • Authors: Szilárd S. Bucs, Nadia Farhat, Luca Fortunato
      First page: 543
      Abstract: Water scarcity is the main factor driving the enhancement of available technologies and the development of new technologies [...]
      Citation: Membranes
      PubDate: 2022-05-23
      DOI: 10.3390/membranes12050543
      Issue No: Vol. 12, No. 5 (2022)
  • Membranes, Vol. 12, Pages 544: Ultrafiltration Membranes Functionalized
           with Copper Oxide and Zwitterions for Fouling Resistance

    • Authors: Cannon Hackett, Mojtaba Abolhassani, Lauren F. Greenlee, Audie K. Thompson
      First page: 544
      Abstract: Polymeric membrane fouling is a long-standing challenge for water filtration. Metal/metal oxide nanoparticle functionalization of the membrane surface can impart anti-fouling properties through the reactivity of the metal species and the generation of radical species. Copper oxide nanoparticles (CuO NPs) are effective at reducing organic fouling when used in conjunction with hydrogen peroxide, but leaching of copper ions from the membrane has been observed, which can hinder the longevity of the CuO NP activity at the membrane surface. Zwitterions can reduce organic fouling and stabilize NP attachment, suggesting a potential opportunity to combine the two functionalizations. Here, we coated polyethersulfone (PES) ultrafiltration membranes with polydopamine (PDA) and attached the zwitterionic compound, thiolated 2-methacryloyloxyethyl phosphorylcholine (MPC-SH), and CuO NPs. Functionalized membranes resulted in a higher flux recovery ratio (0.694) than the unfunctionalized PES control (0.599). Copper retention was high (>96%) for functionalized membranes. The results indicate that CuO NPs and MPC-SH can reduce organic fouling with only limited copper leaching.
      Citation: Membranes
      PubDate: 2022-05-23
      DOI: 10.3390/membranes12050544
      Issue No: Vol. 12, No. 5 (2022)
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