Subjects -> ENVIRONMENTAL STUDIES (Total: 913 journals)
    - ENVIRONMENTAL STUDIES (810 journals)
    - POLLUTION (31 journals)
    - TOXICOLOGY AND ENVIRONMENTAL SAFETY (54 journals)
    - WASTE MANAGEMENT (18 journals)

POLLUTION (31 journals)

Showing 1 - 27 of 27 Journals sorted by number of followers
Water, Air, & Soil Pollution     Open Access   (Followers: 22)
Aerosol Science and Technology     Hybrid Journal   (Followers: 15)
Water, Air, & Soil Pollution : Focus     Hybrid Journal   (Followers: 7)
Journal of Hazardous, Toxic, and Radioactive Waste     Full-text available via subscription   (Followers: 6)
Journal of Limnology     Open Access   (Followers: 6)
Archives of Environmental Protection     Open Access   (Followers: 5)
Journal of Energy, Environment & Carbon Credits     Full-text available via subscription   (Followers: 5)
Greenhouse Gases : Science and Technology     Hybrid Journal   (Followers: 4)
Journal of the Air & Waste Management Association     Hybrid Journal   (Followers: 4)
Open Journal of Air Pollution     Open Access   (Followers: 4)
Jurnal Pengendalian Pencemaran Lingkungan     Open Access   (Followers: 4)
Ciencias Marinas     Open Access   (Followers: 3)
Energy and Emission Control Technologies     Open Access   (Followers: 3)
Atmospheric Pollution Research     Hybrid Journal   (Followers: 2)
Aerosol Science and Engineering     Hybrid Journal   (Followers: 2)
Journal of Polymers and the Environment     Hybrid Journal   (Followers: 1)
Pollution     Open Access   (Followers: 1)
Emerging Contaminants     Open Access   (Followers: 1)
Current Pollution Reports     Hybrid Journal   (Followers: 1)
Exposure and Health     Hybrid Journal   (Followers: 1)
Environmental Chemistry and Ecotoxicology     Open Access   (Followers: 1)
Microplastics and Nanoplastics     Open Access   (Followers: 1)
Environmental Pollutants and Bioavailability     Open Access   (Followers: 1)
Journal of Air Pollution and Health (رتبه علمی- پژوهشی)     Open Access  
Revista Internacional de Contaminación Ambiental     Open Access  
Latin American Journal of Aquatic Research     Open Access  
Hidrobiológica     Open Access  
Similar Journals
Journal Cover
Journal of Polymers and the Environment
Journal Prestige (SJR): 0.562
Citation Impact (citeScore): 2
Number of Followers: 1  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1566-2543 - ISSN (Online) 1572-8919
Published by Springer-Verlag Homepage  [2468 journals]
  • Degradation Behavior of Poly (Lactic Acid) during Accelerated
           Photo-Oxidation: Insights into Structural Evolution and Mechanical
           Properties

    • Free pre-print version: Loading...

      Abstract: Abstract Poly (lactic acid) (PLA) has received considerable attention as a sustainable and biodegradable alternative to petroleum-based polymers in recent years. In general, the properties of PLA depend on its molecular chain structure, e.g., linear, branched, and aggregated structure, e.g., orthorhombic α-form and stereocomplex crystals. However, the evolution of hierarchical structure triggered by photo-oxidation degradation remain elusive for PLA. Herein, the accelerated photo-oxidation degradation behaviors of PLA samples with different thermal histories, including quenching (PLA-q), slow cooling (PLA-c), and annealing (PLA-a), were investigated by several characterization techniques. Compared to PLA-q and PLA-c, PLA-a exhibits relatively lower rates of molecular chain scission and oxygen-containing groups generation during the accelerated photo-oxidation process, suggesting that the increase in crystallinity contributes to suppressing the degradation of PLA. Changes in the molecular chain structure leads to the evolution of aggregation structure. The crystallinity of PLA samples, whether slowly cooled or annealed, increases with UV exposure time, which is attributed to the newly-formed crystals induced by chemi-crystallization. Unexpectedly, although PLA-a exhibits a slower photo-oxidation degradation rate than PLA-q and PLA-c, it undergoes embrittlement at an earlier stage. Morphological observations of photo-oxidized samples indicate that the degradation reaction of PLA-a occurs preferentially in the amorphous region, transforming the molecular chains into volatile products and eventually resulting in the embrittlement of PLA materials. This research sheds light on photo-oxidation degradation behaviors of PLA, and will serve as a valuable reference for investigating the degradation of other bio-based polymeric materials.
      PubDate: 2024-02-23
       
  • κ-Carrageenan Hydrogels as a Sustainable Alternative for Controlled
           Release of New Biodegradable Molecules with Antimicrobial Activities

    • Free pre-print version: Loading...

      Abstract: Abstract The main objective of the present study was to develop κ-Carragenan (κ-CG) hydrogels by ionic crosslinking, using KCl and NaCl as crosslinkers, as medium controlled releasing of four new cleavable surfactants with antimicrobial activities (C10-MET; C14-MET; C10-BEN and C14-BEN) used as model drugs. The effect of the κ-CG amount on swelling behavior, morphological properties and load/release capacity of surfactants from hydrogels were investigated. The most efficient swelling result was observed for the sample containing a low ratio κ-CG/crosslinker when the swelling medium was distilled water. The hydrogels showed porous structure and elastic solid behavior in the analyzed temperature range (20–200 °C); and were able to load the four drugs by the classic entrapment method. The release results were closely related to the swelling values of the hydrogels and the solubility of the drug in the release medium. It was found that the drug release increased with time, reaching its maximum after 24 h, and C10-MET exhibited the highest percent release. The results of the present work indicate that the κ-CG hydrogels are good support materials for controlled release, with excellent swelling capacity (> 200%), which is a very important property for applications in agriculture.
      PubDate: 2024-02-21
       
  • Mn-Fe Layered Double Hydroxide Modified Cellulose-Based Membrane for
           Sustainable Anionic Pollutant Removal

    • Free pre-print version: Loading...

      Abstract: Abstract This study aimed to investigate the adsorption of As(V), phosphate, and textile dye Acid Green 25 (AG-25) on layered double hydroxides Mn-Fe_LDH and corresponding membranes (wCell/Mn-Fe_LDH). The wCell membrane, derived from waste tobacco boxes, was formed by cross-linking of epoxy and amino modified cellulose fibers with epoxy modified Mn-Fe_LDH and lysine as cross-linker. Structural and morphological analyses were conducted for Mn-Fe_LDH and wCell/Mn-Fe_LDH. The batch system explored pH, contact time, temperature, and initial concentration effects on wCell/Mn-Fe_LDH adsorption efficiency. Adsorption capacities of 82.71, 106.9, and 130.3 mg g−1 were achieved for As(V), phosphate, and AG-25, respectively, indicating effective anionic species removal. Kinetic analysis suggested intraparticle diffusion as the rate-limiting step. Thermodynamic parameters and ionic strength effects indicated a physisorption mechanism for AG-25 and surface complexation for As(V) and phosphate. Biodegradation experiments after five adsorption/desorption cycles revealed the membrane’s decomposition, with phosphate’s strong bonding releasing essential elements valuable for soil fertilization. Effluent wastewater treatment demonstrated low environmental impact through the formation of insoluble As(V) salts and photocatalytic dye degradation.
      PubDate: 2024-02-20
       
  • Correction to: Design and Evaluation of Natural Degradation Behavior of
           Poly (lactic acid)/Organo-Modifed-Ni-Zn-Al-Layered Double Hydroxides
           Nanocomposites Film

    • Free pre-print version: Loading...

      PubDate: 2024-02-19
       
  • Synthesis, Properties, and Degradation of Poly(butylene
           succinate-co-sebacicate-co-salicylicate) Copolyesters

    • Free pre-print version: Loading...

      Abstract: Abstract Since monomers in backbone of poly(butylene succinate-co-adipate) (PBSA) are not entirely derived from bio-based sources, limiting its application in the face of increasingly stringent environmental policies. In this study, a novel full bio-based biodegradable random copolyester poly(butylene succinate-co-sebacicate-co-salicylicate) was successfully synthesized. Detailed investigations were conducted on the structural, mechanical, and degradation characteristics resulting from the introduction of salicylicate and sebacicate units. Introduction of salicylicate units effectively enhanced the mechanical performance. In comparison to PBSA, the tensile modulus of copolymer increased by 20.2% with 10% salicylic acid. Introduction of sebacicate units significantly altered the crystalline structure of copolymer and promote the degradation efficiency. Considering both mechanical strength and degradation efficiency, the copolyester with 2% salicylic acid and 20% sebacic acid was found to meet practical application requirements. Relative to PBSA, this copolymer demonstrated a 13.7% increase in tensile modulus and a remarkable 143.1% improvement in degradation efficiency. Importantly, this study focused on the effect of the bio-based rigid monomer salicylic acid and the soft monomer sebacic acid on the degradability of biodegradable polymers. The insights gained provide valuable guidance for tailoring the synthesis of degradable plastics to meet diverse degradation cycle requirements.
      PubDate: 2024-02-19
       
  • Utilization of Pineapple Peel Waste/ZnO Nanoparticles Reinforcement for
           Cellulose-Based Nanocomposite Membrane and Its Characteristics

    • Free pre-print version: Loading...

      Abstract: Bacterial cellulose (BC) is a natural substance produced by microorganisms and offers numerous benefits. It can be produced by utilizing biomass waste which is abundantly available through fermentation process. This study investigates the utilization of pineapple peel waste for BC synthesis and observes their properties as nanocomposite membranes after the addition of ZnO nanoparticles (ZnO-NPs) as candidate biomaterials for water filtration membranes. The experimental methods were conducted by synthesizing BC using pineapple peel extract using fermentation process. Subsequently, BNC was produced using a high-pressure homogenizer, and ZnO-NPs nanoparticles were added as reinforcement at concentrations of 2.5 wt%, 5.0 wt%, and 7.5wt.%. The mixture was sonicated and subsequently dried in an oven at 60°C for 20 h. BNC/ZnO-NPs membranes were characterized using XRD, FTIR, tensile test, BET, antibacterial test, and SEM analysis. The results indicate that the membrane structure of BNC/ZnO-NPs nanocomposite has peaks at diffraction angles of 14.4°, 15.2°, 16.9°, 22.8°, 31.6°, 34.1° and 36.8°. The addition of ZnO-NPs enhances the crystalline index of BNC by 81.37% at 2.5wt.% ZnO-NPs but reduces the membrane strength due to increasing pore diameter and rougher surface morphology of membrane. Incorporation of ZnO-NPs results in membrane chemical bonding, proved by raising a new peak at wavenumber of 715 cm− 1 and reduces the transmittance of hydroxyl group. This showed antibacterial activity against gram-positive bacteria like S.aureus, but they have no effect on gram-negative bacteria like E. coli. This antibacterial activity is good for resisting biofouling and the membrane can be further developed to meet the requirements for field water filtration applications like desalination. Graphical
      PubDate: 2024-02-19
       
  • Recent Progress in Enhanced Optical, Mechanical, Thermal Properties, and
           Antibacterial Activity of the Chitosan/Polyvinylalcohol/Co3O4
           Nanocomposites for Optoelectronics and Biological Applications

    • Free pre-print version: Loading...

      Abstract: Abstract The present study explores the influence of Cobalt oxide nanoparticles(Co3O4 NPs) on the physicochemical characteristics of Poly(vinylalcohol)/ Chitosan (PVA/Cs) blend. Using a variety of techniques, the pure blend and the nanocomposites’ composition, structure, optical, thermal, and mechanical properties, and antibacterial activity were characterized. The Co3O4 NPs were produced by precipitation method utilizing cobalt salt as the raw material. The crystalline nature of the nanoparticles and semi-crystalline behavior of the PVA/Cs are demonstrated by the XRD data. Adding nanoparticles to the pure blend reduced the intensity of the semi-crystalline. The rise in absorption intensity observed in UV-visible spectra upon the incorporation of Co3O4 NPs into the PVA/Cs blend indicates an improved dispersion of the nanoparticles within the blend. When Co3O4 NPs are added, the energy band-gap Egdir and Egind of PVA/Cs–Co3O4 samples greatly decrease. According to TGA data, the thermal stability of nanocomposites was significantly higher than that of the PVA/Cs blend, and it rose as the concentration of nanoparticles increased. When compared to neat PVA/Cs film, mechanical property investigation of PVA/Cs–Co3O4 nanocomposites films revealed enhanced features. The effectiveness of the PVA/Cs–Co3O4 nanocomposite films in inhibiting the growth of microorganisms was assessed by evaluating their antimicrobial activity (ANMAC) against a range of bacteria and fungi. The inclusion of Co3O4 NPs led to an increase in activity against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacteria as well as fungi Candida albicans and Aspergillus niger (C. albicans and A. niger). The addition of Co3O4 NPs to the PVA/Cs blend effectively improved the material’s optical, thermal, mechanical, and antibacterial properties. This remarkable improvement stems from the Co3O4 NPs, which were introduced into the PVA/Cs blend in different amounts, leading to the development of novel nanocomposites. The outstanding properties of Co3O4/PVA/Cs nanocomposite films suggest their potential for applications in optoelectronics and food packaging.
      PubDate: 2024-02-19
       
  • Valorisation of Salvia Hispanica L. (Chia) Oil into Air-Drying Alkyd
           Resins: Towards Solvent-Free Nanodispersion Formulations and Their
           Oxidative Miniemulsion Polymerisation

    • Free pre-print version: Loading...

      Abstract: Abstract The current work was developed focusing on the synthesis of new polymeric latexes through the in reactor oxidative polymerisation of chia oil alkyd resins using the miniemulsion process. These latexes have potential applications, primarily in coating applications. Initially, an oil length mixture was obtained from chia oil through saponification and acidification reactions. The resulting mixture was characterized by 1H-NMR and 13C-NMR, confirming the presence of unsaturation and the characteristic functional groups associated with this compound. Phthalic anhydride and glycerol (esterification reaction) were used in the synthesis of alkyd resin. Alkyd resins were obtained by varying the oil length content in its composition: 30% wt% oil length alkyd resin is called short alkyd resin, 43% wt% oil length is medium resin and 64% wt% is the long alkyd resin. The 1H NMR spectra of alkyd resins showed peaks indicative of the presence of groups coming from phthalic anhydride and glycerol, as well as unsaturations that varied in intensity according to the size of the resin (short, medium or long). The miniemulsions were obtained from alkyd resins demonstrating colloidal stability over 90 days and with stable miniemulsions the oxidative polymerisation of the alkyd resins was carried out in a high-pressure reactor with temperature and pressure control and in the presence of the radicalinitiator benzoyl peroxide (BPO) and oxygen. Based on 1H-NMR analysis, polymers are formed through the oxidative polymerisation of alkyd resins from chia oil using the miniemulsion process. These polymers can be used as a paint base with a low solvent fraction or no solvent, depending on the application, and without using heavy metals-based catalysts.
      PubDate: 2024-02-19
       
  • Synthesis and Characterization of PEGylated Poly(Glycerol Azelaic Acid)
           and Their Nanocomposites for Application in Tissue Engineering

    • Free pre-print version: Loading...

      Abstract: In this study, new types of bio-copolymers based on Poly(glycerol azelaic acid) (PGAZ) and Poly(ethylene glycol) (PEG) (Mn=400, 1000, and 2000 gmol−1) were synthesized by melt polycondensation technique. Also, the solution casting method prepared their nanocomposites with 5 wt% of bioactive glass nanoparticles (BG). 1H-NMR and FTIR analysis confirmed that the pre-polymer resins were well synthesized. Crystalline plan (002) of PGAZ-co-PEG1000 and PGAZ-co-PEG2000 are increased compared to other samples. The SEM images of the surface of the samples showed that the increase in the molecular weight of PEG has made the surface morphology rougher, and the presence of nanoparticles causes a layered morphology. Also, the increase in molecular weight in PEG has caused better dispersion of nanoparticles. Among all the samples, the mechanical properties of PGAZ-co-PEG2000/BG were higher than others. The glass transition temperature (Tg) for the PGAZ sample is around 42.16 oC, and by copolymerizing this material with PEG, the Tg values have moved to lower temperatures. The degradation behaviour of PGAZ-co-PEG1000 and its nanocomposites was faster in fetal bovine serum (FBS) moiety. The dynamic contact angle showed that sample PGAZ-co-PEG400 showed the best hydrophilic conditions, and on the other hand, the PGAZ/BG sample behaved better among the nanocomposite samples. The behaviour of cytotoxicity after 72 h showed that the samples PGAZ-co-PEG400/BG and PGAZ-co-PEG2000/BG had better cell maintenance and proliferation. Cell adhesion is more on the surface of nanocomposite samples, and the acridine orange technique also showed that after 16 days, there are cells with very high density on the surface of bio-copolymer nanocomposite samples. Graphical
      PubDate: 2024-02-16
       
  • Understanding the Interaction Between Gelatin and a Layered Silicate and
           

    • Free pre-print version: Loading...

      Abstract: Abstract Laponite® (Lap) is a synthetic layered nanoclay that is considered a potential candidate for improving the physicochemical properties of gelatin films. However, there is limited information in the literature about the interaction between Lap platelets and gelatin chains and its impact on the physicochemical film properties. Therefore, the current research aimed to systematically study the mechanism of interaction and the effect of Lap on the physicochemical properties of gelatin films (moisture content, optical properties, water contact angle, surface energy, water adsorption, water solubility, water vapor permeability, and mechanical properties). Furthermore, gelatin films with Lap were applied as UV-barrier materials in grape juice. Gelatin films were produced by casting method containing 0, 3, 5, 10, and 15% of Lap (based on the weight of the biopolymer). The incorporation of Lap reduced the formation of the gelatin triple helix structure and consequently film crystallinity. Hydrogen bonds and electrostatic interactions could be the principal interactions between gelatin/glycerol/Lap. The incorporation of Lap increased the thickness and moisture content. Lap platelets were completely exfoliated and did not modify the color and opacity of the gelatin films. The UV-barrier capacity of the gelatin films was improved with the incorporation of Lap. Gelatin films with 15% Lap exhibited a transmittance decreases of 86% and 5% in ultraviolet (280 nm) and visible (470 nm) light, respectively. Furthermore, a reduction of 29% in film water solubility was observed with 15% Lap. Other properties such as water contact angle, surface free energy, water vapor permeability, and mechanical properties were not modified by the incorporation of Lap. Gelatin films containing Lap (15%) reduced the degradation of anthocyanins (50%) in grape juice exposed to UV light when compared with samples covered with gelatin films without Lap.
      PubDate: 2024-02-08
       
  • Green Synthesis of Nanochitosan/Bentonite/SnO2–ZnO Bionanocomposite for
           

    • Free pre-print version: Loading...

      Abstract: Abstract Biotreatment of wastewater has attracted considerable attention due to its low cost and eco-friendliness. This study developed a novel bionanocomposite comprised of Nanochitosan (NCS), Bentonite (Bt), and SnO2–ZnO nanocomposite prepared using Salvia officinalis extract as a reducing/stabilizing agent. The NCS/Bt/SnO2–ZnO bionanocomposite exhibited a rough surface with porous nature. EDX, XRD, and FTIR results confirmed the formation of the bionanocomposite. TGA indicated high thermal stability of the NCS/Bt/SnO2–ZnO. DRS results revealed that the bionanocomposite had a band gap of 2.60 eV. The surface area of NCS/Bt/SnO2–ZnO was found to be 32.54 m2 g−1 with a 17.98 nm pore size. Adsorption of Fe(III) and Pb(II) ions and photocatalytic degradation of methylene blue (MB) dye using this bionanocomposite were studied. Under optimal conditions, the highest removal of Fe(III) (99.5%) and Pb(II) (91.5%) was achieved after 5 min and 40 min, respectively. The adsorption data fitted the Langmuir isotherm and indicated the removal capacity of 555.55 and 243.90 mgg−1 for Fe(III) and Pb(II), respectively. Also, the NCS/Bt/SnO2–ZnO showed the MB dye degradation efficiency of 99% within 30 min. Therefore, the NCS/Bt/SnO2–ZnO can be used as an environmentally friendly, cost-effective, thermally stable, and high-performance adsorbent/photocatalyst to remove heavy metal ions and dye molecules.
      PubDate: 2024-02-08
       
  • Preparation and Characterization of Cinnamon–Clove Compound Essential
           Oil Microcapsules/Graphene Oxide/Polyvinyl Alcohol/Polylactic Acid
           Composite Films for White Beech Mushrooms Packaging

    • Free pre-print version: Loading...

      Abstract: This work developed a novel, environmental, and safe cinnamon–clove compound essential oil microcapsules/graphene oxide/polyvinyl alcohol/polylactic acid (CCCEOM/GO/PVA/PLA) composite films for the fresh-keeping packaging of white beech mushrooms and investigated the effects of essential oils and nano-fillers on prolonging food shelf life. Herein, PVA and PLA were blended to reduce the water solubility and improve the mechanical properties of the composites. The lamellar GO, a nucleating agent, was prepared using the modified Hummer method. Clove and cinnamon essential oils have been blended to obtain composite essential oils with better antibacterial activity and encapsulated in beta-cyclodextrin (β-CD) to produce CCCEOM, a sustained-release antibacterial agent. The CCCEOM/GO/PVA/PLA composites were fabricated by integrating GO and CCCEOM into the PVA/PLA matrix, and the morphology, water solubility, optical properties, mechanical properties, thermal stability, and oxygen permeability of the composites were characterized. It was found that the composites demonstrated significant antibacterial activity against Mucor and Aspergillus niger, low water solubility (0.009%), high light transmittance (84.63%), as well as excellent tensile strength (42.29 MPa), and oxygen transmission rate (82.65 cm3/(m2·24 h·0.1 MPa)) with the addition of 0.20 wt% GO and 10 wt% CCCEOM. Moreover, the results of the preservation experiment demonstrate that it can also maintain the quality of white beech mushrooms to some extent and prolong their shelf life for 4 days at 4 °C, which also provides support for their application in food packaging. Graphical
      PubDate: 2024-02-07
       
  • Development of 3D-Printed PCL/ Baghdadite Nanocomposite Scaffolds for Bone
           Tissue Engineering Applications

    • Free pre-print version: Loading...

      Abstract: Abstract A significant obstacle in bone tissue engineering is the creation of biodegradable bone replacements with the requisite mechanical and biological capabilities to treat more severe and intricately shaped injuries. Baghdadite has recently indicated that active biological ions such as silicon (Si4+) and zirconium (Zr4+) have been proven to increase bone growth considerably. In this study, we produced 3D-printed PCL-based scaffolds containing different amounts of Baghdadite using the robocasting solvent technique. Notably, PCL with 40 and 60 wt.% Baghdadite scaffolds (PB40 and PB60) promoted a more biomimetic environment for in vitro bone growth as their proper bioactivity and cell viability results were obtained without the addition of osteoinductive components. The printing process produced 3D scaffolds with a compressive strength of 7.94 MPa and elastic modulus of 29.95 MPa in PB40. According to the analytical prediction models in PB40, the elastic modulus was 24.7 and 26.89 MPa. Also, adding 60 wt.% Baghdadite increased the degradation rate to 5.1% in two months, more than six times that of PCL-based scaffolds. Cell proliferation assay demonstrated that the optical density of MG63 cells after 7 days of culture increased from 1.43 ± 0.03 to 1.82 ± 0.20 in PB40 as compared to pure PCL scaffold. Furthermore, bioactivity evaluation, ion release assessment, and morphological observation results further revealed that incorporating Baghdadite into a 3D-printed PCL-based scaffold could improve bone regeneration. Our findings demonstrate that the PCL/Baghdadite composite scaffold may be efficiently manufactured using 3D-printing technology and is extremely promising for bone tissue engineering applications.
      PubDate: 2024-02-06
       
  • Bioinspired Self-Assembly Polymer Based on Nucleobase for Enhanced Oil
           Recovery

    • Free pre-print version: Loading...

      Abstract: Abstract Polymer flooding is one of the most effective tertiary oil recovery technologies, which can significantly improve the sweep efficiency of the reservoir by injecting high-viscosity polymer solution. However, Conventional polymers are difficult to inject, easy to degrade after shearing, cause plugging in low-permeability reservoirs, functional monomers have potential environmental pollution risks, and limit its industrial application. In recent years, more and more attention has been paid to the development of adaptive supramolecular oil displacement materials from bio-based materials. Here, the bases of guanine and cytosine from ribonucleic acid are grafted onto polyacrylamide. With a multi-supramolecular interactions through synergistic hydrogen bonding and hydrophobic interactions, HPAM-C≡G-HPAM with excellent injectivity and high viscosity are developed to improve the recovery of low permeability reservoirs. Subsequently, HPAM-C≡G-HPAM was characterized by FT-IR, NMR, ESEM and DLS. The rheological test results show that the tackifying ability of the supramolecular system is much higher than that of polyacrylamide with the same molecular weight and has excellent shear resistance. In the laboratory core displacement experiment, the injection pressure of HPAM-C≡G-HPAM in low permeability core is only 1/3 of that of polyacrylamide with the same viscosity, and the oil recovery can be increased by 16.31%, The oil recovery can be increased by 10% under high temperature and high salinity conditions. Accordingly, HPAM-C≡G-HPAM has the potential to greatly enhance oil recovery in low permeability reservoirs.
      PubDate: 2024-02-05
       
  • QPCR-Guided Screening of Levansucrase: Levan Characterization and Genomic
           Insights

    • Free pre-print version: Loading...

      Abstract: Abstract Eighty-seven bacteria isolates were screened for the presence of the levansucrase encoding gene and those possessing the gene were used in gene expression studies and the production of levan. Based on both screening methods, isolate P19-1 was determined as the producer bacterium with the highest amounts of levan. Whole genome sequencing was done to characterize the isolate and determine its genomic potential. Both its 16 S rRNA and genome were closest to Chromohalobacter salexigens. The levansucrase gene and genes suggesting a versatile carbohydrate and nitrogen metabolism were annotated. A secondary metabolism suggestive of a possible new role in promoting plant growth in hypersaline environments was revealed. The chemical structure analysis of the produced polymer was confirmed by comparison with commercial pure Erwinia herbicola levan. Also, C. salexigens levan showed high biocompatibility. Overall, this is a practical molecular approach that will help researchers to effectively screen microbes with levan production potential.
      PubDate: 2024-02-05
       
  • Enhancing the Sustainability of Poly(Lactic Acid) (PLA) Through
           Ketene-Based Chain Extension

    • Free pre-print version: Loading...

      Abstract: The widespread utilization of nonrenewable fossil-based polymers has led to significant environmental damage. Bio-based Poly(lactic acid) (PLA) has garnered substantial academic and industrial interest in the last two decades due to its advantageous characteristics for food packaging applications. Nonetheless, the improper disposal of PLA continues to contribute to the plastic waste problem. PLA recycling mainly involves thermal processes, facing challenges due to PLA’s limited stability. This study aims to enhance PLA’s molecular weight and melt viscosity by using chain extenders to increase its degree of branching. A modular chain extender capable of thermally forming highly reactive ketene intermediates is employed to react with PLA’s hydroxyl and carboxyl end groups in a single step. For this purpose, copolymers of styrene and 2,2,5-trimethyl-5-(4-vinylbenzyl)-1,3-dioxane-4,6-dione were synthesized using free radical polymerization and characterized through 1H-NMR, TGA, and DSC analyses. The chemical interaction between these chain extenders and molten PLA was also explored, resulting in increased PLA molecular weight and higher melting temperature (Tm), reaching 155.1 for PLA_2.5CE2. Additionally, the branching introduced through this process led to a notable increase in the UV absorption of PLA, suggesting potential applications in the packaging industry. The chemical tunability of this functional ketene-based chain extender holds promise for tailoring PLA’s structure for diverse applications, further advancing its sustainability and utility. Graphical
      PubDate: 2024-02-03
       
  • Biodegradable Conducting PVA-Hydrogel Based on Carbon Quantum Dots: Study
           of the Synergistic Effect of Additives

    • Free pre-print version: Loading...

      Abstract: Conductive hydrogels are becoming one of the most important milestones for the development of new scaffolds, biosensors, supercapacitors, and green electronics within the field of biomedicine. In this work, we study the effect of different types of electroactive additives such as poly(3,4-ethylenedioxythiophene), tannic acid, and carbon quantum dots (CQDs), to form different poly(vinyl alcohol) (PVA)-based hydrogels with enhanced electrochemical properties. Different physicochemical tests are carried out to characterize the different PVA-based hybrid hydrogels and the rates of their degradation and loss of electroactivity throughout an eight-week biodegradation process. This work shows the individual and synergistic effects of the additives on various mechanical properties, including storage modulus and swelling ratio, and electrochemical properties of the PVA hydrogel. The additives have proven to enhance the electroactivity of the PVA-based hydrogels but as well their degradation. Finally, the use of the new hydrogel as a pressure sensor is also investigated. The study provides an insight on the potential use of CQDs, in synergy with other electroactivity enhancers, in the fabrication of novel hybrid conducting hydrogels in green electronics. Graphical
      PubDate: 2024-02-03
       
  • Development of Microstructured Chitosan Nanocapsules with Immobilized
           Lipase

    • Free pre-print version: Loading...

      Abstract: This study developed three microstructured chitosan nanocapsules with immobilized lipase to explore chitosan-lipase interactions at different pH levels. Chitosan undergoes complete protonation or deprotonation based on pH level. Three distinct pH levels were examined: 5.5, where chitosan is fully protonated; 6.5, where chitosan is partially protonated/deprotonated; and 7.5, where chitosan is fully deprotonated. The nanocapsules exhibited nanoscale dimensions and the microstructures showed porous morphology. Immobilized lipase showed improved temperature stability, compared to free enzyme, especially in lipase supports at pH 5.5 and 7.5 due to electrostatic and hydrophobic interactions. The interactions between chitosan and lipase influenced the microenvironment around the active site, resulting in an optimum pH of 8 for all supports. Immobilized lipase at pH 5.5 and 7.5 displayed the best reusability in the hydrolysis of p-nitrophenyl palmitate under reaction conditions of 37 °C and pH 8. During refrigeration storage, all immobilized lipases maintained total activity for 7 days, but lipase immobilized at pH 6.5 maintained more the activity after 28 days. Therefore, this study has developed promising immobilized lipase, standing out not only for industrial application concerning cost-effectiveness, but also for the innovation in investigating the influence of chitosan-lipase interactions during immobilization. Graphical
      PubDate: 2024-02-03
       
  • The Impact of Temperature on the Formation, Release Mechanism, and
           Degradation of PLGA-based In-Situ Forming Implants

    • Free pre-print version: Loading...

      Abstract: This study explores the impact of varying temperatures on the release behavior of Triptorelin Acetate (TA) from a PLGA-based in-situ forming implant (ISFI) and polymer degradation. Formulations were prepared using the in situ forming method in an acetate buffer (pH = 6.8) and then exposed to temperatures of 4 to 60 °C. The drug release and polymeric depot behavior were evaluated using HPLC, SEM, GPC, Rheometer, and pH measurements. A modified Gallagher-Corrigan Model-based mathematical model was applied to fit the in-vitro data, and the activation energy for peptide release in diffusional and erosional phases was calculated using the Arrhenius equation. The results revealed that matrices formed at 37, 45, and 53 °C exhibited a highly porous structure, resulting from rapid phase inversion and surface pore closing. This led to a reduction in TA burst release, observed as 38%, 27%, and 15% at 37 °C, 45 °C, and 53 °C respectively. Conversely, matrices at 4 and 25 °C demonstrated a faster initial release, followed by the formation of dense structures. The accelerated drug release profiles at 45 and 53 °C showed a shortened ultimate drug release duration and a good correlation with the real-time results at 37 °C. Due to the discernible PLGA matrices degradation at different temperatures, biphasic and tri-phasic release patterns were observed. The experimental release results aligned well with the proposed mathematical model, and the drug release kinetic parameters were estimated. Thus, in in-vitro studies, the release medium temperature plays a significant role in the drug-release behavior of ISFIs. Graphical
      PubDate: 2024-02-03
       
  • Bioinks Functionalized with Natural Extracts for 3D Printing

    • Free pre-print version: Loading...

      Abstract: Abstract In the search of materials valid for direct ink writing (DIW) 3D printing and with special interest for the biomedical and pharmaceutical applications, the development of bioactive inks for DIW is of great interest. For that purpose, in this work bioactive waterborne polyurethane–urea inks were prepared by addition of natural extracts (logwood, chestnut, and alder buckthorn) and cellulose nanofibers (CNF). The rheological behavior of the inks proved to be strongly dependent on the extract type and content, and the addition route used. Inks prepared by ex-situ incorporation of the extracts showed a strong gel-like behavior, as did inks prepared with chestnut and alder buckthorn extracts, which, in turn, hindered a continuous flow during the printing process, resulting in 3D printed parts with poor shape fidelity. On the other hand, inks prepared in-situ and with logwood extract showed more facility to flow and higher homogeneity, which translated in better printability and better shape fidelity, further enhanced for CNF containing inks. 3D printed composites showed reinforced mechanical behavior, as well as in materials with enhanced antibacterial behavior. Overall, the possibility to successfully prepare bioactive inks valid for 3D printing was proven.
      PubDate: 2024-02-01
       
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 34.204.169.230
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-
JournalTOCs
 
 
  Subjects -> ENVIRONMENTAL STUDIES (Total: 913 journals)
    - ENVIRONMENTAL STUDIES (810 journals)
    - POLLUTION (31 journals)
    - TOXICOLOGY AND ENVIRONMENTAL SAFETY (54 journals)
    - WASTE MANAGEMENT (18 journals)

POLLUTION (31 journals)

Showing 1 - 27 of 27 Journals sorted by number of followers
Water, Air, & Soil Pollution     Open Access   (Followers: 22)
Aerosol Science and Technology     Hybrid Journal   (Followers: 15)
Water, Air, & Soil Pollution : Focus     Hybrid Journal   (Followers: 7)
Journal of Hazardous, Toxic, and Radioactive Waste     Full-text available via subscription   (Followers: 6)
Journal of Limnology     Open Access   (Followers: 6)
Archives of Environmental Protection     Open Access   (Followers: 5)
Journal of Energy, Environment & Carbon Credits     Full-text available via subscription   (Followers: 5)
Greenhouse Gases : Science and Technology     Hybrid Journal   (Followers: 4)
Journal of the Air & Waste Management Association     Hybrid Journal   (Followers: 4)
Open Journal of Air Pollution     Open Access   (Followers: 4)
Jurnal Pengendalian Pencemaran Lingkungan     Open Access   (Followers: 4)
Ciencias Marinas     Open Access   (Followers: 3)
Energy and Emission Control Technologies     Open Access   (Followers: 3)
Atmospheric Pollution Research     Hybrid Journal   (Followers: 2)
Aerosol Science and Engineering     Hybrid Journal   (Followers: 2)
Journal of Polymers and the Environment     Hybrid Journal   (Followers: 1)
Pollution     Open Access   (Followers: 1)
Emerging Contaminants     Open Access   (Followers: 1)
Current Pollution Reports     Hybrid Journal   (Followers: 1)
Exposure and Health     Hybrid Journal   (Followers: 1)
Environmental Chemistry and Ecotoxicology     Open Access   (Followers: 1)
Microplastics and Nanoplastics     Open Access   (Followers: 1)
Environmental Pollutants and Bioavailability     Open Access   (Followers: 1)
Journal of Air Pollution and Health (رتبه علمی- پژوهشی)     Open Access  
Revista Internacional de Contaminación Ambiental     Open Access  
Latin American Journal of Aquatic Research     Open Access  
Hidrobiológica     Open Access  
Similar Journals
Similar Journals
HOME > Browse the 73 Subjects covered by JournalTOCs  
SubjectTotal Journals
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 34.204.169.230
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-