Publisher: Hindawi   (Total: 343 journals)

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Showing 1 - 200 of 343 Journals sorted alphabetically
Abstract and Applied Analysis     Open Access   (Followers: 3, SJR: 0.343, CiteScore: 1)
Active and Passive Electronic Components     Open Access   (Followers: 8, SJR: 0.136, CiteScore: 0)
Advances in Acoustics and Vibration     Open Access   (Followers: 51, SJR: 0.147, CiteScore: 0)
Advances in Aerospace Engineering     Open Access   (Followers: 66)
Advances in Agriculture     Open Access   (Followers: 12)
Advances in Artificial Intelligence     Open Access   (Followers: 22)
Advances in Astronomy     Open Access   (Followers: 51, SJR: 0.257, CiteScore: 1)
Advances in Bioinformatics     Open Access   (Followers: 20, SJR: 0.565, CiteScore: 2)
Advances in Biology     Open Access   (Followers: 11)
Advances in Chemistry     Open Access   (Followers: 35)
Advances in Civil Engineering     Open Access   (Followers: 51, SJR: 0.539, CiteScore: 1)
Advances in Computer Engineering     Open Access   (Followers: 8)
Advances in Condensed Matter Physics     Open Access   (Followers: 11, SJR: 0.315, CiteScore: 1)
Advances in Decision Sciences     Open Access   (Followers: 4, SJR: 0.303, CiteScore: 1)
Advances in Electrical Engineering     Open Access   (Followers: 52)
Advances in Electronics     Open Access   (Followers: 101)
Advances in Emergency Medicine     Open Access   (Followers: 16)
Advances in Endocrinology     Open Access   (Followers: 6)
Advances in Environmental Chemistry     Open Access   (Followers: 10)
Advances in Epidemiology     Open Access   (Followers: 9)
Advances in Fuzzy Systems     Open Access   (Followers: 5, SJR: 0.161, CiteScore: 1)
Advances in Geology     Open Access   (Followers: 19)
Advances in Geriatrics     Open Access   (Followers: 6)
Advances in Hematology     Open Access   (Followers: 13, SJR: 0.661, CiteScore: 2)
Advances in Hepatology     Open Access   (Followers: 3)
Advances in High Energy Physics     Open Access   (Followers: 26, SJR: 0.866, CiteScore: 2)
Advances in Human-Computer Interaction     Open Access   (Followers: 21, SJR: 0.186, CiteScore: 1)
Advances in Materials Science and Engineering     Open Access   (Followers: 31, SJR: 0.315, CiteScore: 1)
Advances in Mathematical Physics     Open Access   (Followers: 9, SJR: 0.218, CiteScore: 1)
Advances in Medicine     Open Access   (Followers: 3)
Advances in Meteorology     Open Access   (Followers: 24, SJR: 0.48, CiteScore: 1)
Advances in Multimedia     Open Access   (Followers: 1, SJR: 0.173, CiteScore: 1)
Advances in Nonlinear Optics     Open Access   (Followers: 7)
Advances in Numerical Analysis     Open Access   (Followers: 9)
Advances in Nursing     Open Access   (Followers: 37)
Advances in Operations Research     Open Access   (Followers: 13, SJR: 0.205, CiteScore: 1)
Advances in Optical Technologies     Open Access   (Followers: 4, SJR: 0.214, CiteScore: 1)
Advances in Optics     Open Access   (Followers: 9)
Advances in OptoElectronics     Open Access   (Followers: 6, SJR: 0.141, CiteScore: 0)
Advances in Orthopedics     Open Access   (Followers: 11, SJR: 0.922, CiteScore: 2)
Advances in Pharmacological and Pharmaceutical Sciences     Open Access   (Followers: 8, SJR: 0.591, CiteScore: 2)
Advances in Physical Chemistry     Open Access   (Followers: 13, SJR: 0.179, CiteScore: 1)
Advances in Polymer Technology     Open Access   (Followers: 14, SJR: 0.299, CiteScore: 1)
Advances in Power Electronics     Open Access   (Followers: 44, SJR: 0.184, CiteScore: 0)
Advances in Preventive Medicine     Open Access   (Followers: 6)
Advances in Public Health     Open Access   (Followers: 28)
Advances in Regenerative Medicine     Open Access   (Followers: 4)
Advances in Software Engineering     Open Access   (Followers: 11)
Advances in Statistics     Open Access   (Followers: 10)
Advances in Toxicology     Open Access   (Followers: 4)
Advances in Tribology     Open Access   (Followers: 15, SJR: 0.265, CiteScore: 1)
Advances in Urology     Open Access   (Followers: 13, SJR: 0.51, CiteScore: 1)
Advances in Virology     Open Access   (Followers: 8, SJR: 0.838, CiteScore: 2)
AIDS Research and Treatment     Open Access   (Followers: 2, SJR: 0.758, CiteScore: 2)
Analytical Cellular Pathology     Open Access   (Followers: 3, SJR: 0.886, CiteScore: 2)
Anatomy Research Intl.     Open Access   (Followers: 4)
Anemia     Open Access   (Followers: 6, SJR: 0.669, CiteScore: 2)
Anesthesiology Research and Practice     Open Access   (Followers: 15, SJR: 0.501, CiteScore: 1)
Applied and Environmental Soil Science     Open Access   (Followers: 20, SJR: 0.451, CiteScore: 1)
Applied Bionics and Biomechanics     Open Access   (Followers: 7, SJR: 0.288, CiteScore: 1)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 15)
Archaea     Open Access   (Followers: 4, SJR: 0.852, CiteScore: 2)
Autism Research and Treatment     Open Access   (Followers: 36)
Autoimmune Diseases     Open Access   (Followers: 3, SJR: 0.805, CiteScore: 2)
Behavioural Neurology     Open Access   (Followers: 9, SJR: 0.786, CiteScore: 2)
Biochemistry Research Intl.     Open Access   (Followers: 6, SJR: 0.437, CiteScore: 2)
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11, SJR: 0.419, CiteScore: 2)
BioMed Research Intl.     Open Access   (Followers: 5, SJR: 0.935, CiteScore: 3)
Biotechnology Research Intl.     Open Access   (Followers: 1)
Bone Marrow Research     Open Access   (Followers: 2, SJR: 0.531, CiteScore: 1)
Canadian J. of Gastroenterology & Hepatology     Open Access   (Followers: 4, SJR: 0.867, CiteScore: 1)
Canadian J. of Infectious Diseases and Medical Microbiology     Open Access   (Followers: 8, SJR: 0.548, CiteScore: 1)
Canadian Respiratory J.     Open Access   (Followers: 3, SJR: 0.474, CiteScore: 1)
Cardiology Research and Practice     Open Access   (Followers: 11, SJR: 1.237, CiteScore: 4)
Cardiovascular Therapeutics     Open Access   (Followers: 2, SJR: 1.075, CiteScore: 2)
Case Reports in Anesthesiology     Open Access   (Followers: 11)
Case Reports in Cardiology     Open Access   (Followers: 8, SJR: 0.219, CiteScore: 0)
Case Reports in Critical Care     Open Access   (Followers: 12)
Case Reports in Dentistry     Open Access   (Followers: 8, SJR: 0.229, CiteScore: 0)
Case Reports in Dermatological Medicine     Open Access   (Followers: 2)
Case Reports in Emergency Medicine     Open Access   (Followers: 19)
Case Reports in Endocrinology     Open Access   (Followers: 2, SJR: 0.209, CiteScore: 1)
Case Reports in Gastrointestinal Medicine     Open Access   (Followers: 3)
Case Reports in Genetics     Open Access   (Followers: 2)
Case Reports in Hematology     Open Access   (Followers: 9)
Case Reports in Hepatology     Open Access   (Followers: 2)
Case Reports in Immunology     Open Access   (Followers: 6)
Case Reports in Infectious Diseases     Open Access   (Followers: 6)
Case Reports in Medicine     Open Access   (Followers: 3)
Case Reports in Nephrology     Open Access   (Followers: 5)
Case Reports in Neurological Medicine     Open Access   (Followers: 1)
Case Reports in Obstetrics and Gynecology     Open Access   (Followers: 11)
Case Reports in Oncological Medicine     Open Access   (Followers: 2, SJR: 0.204, CiteScore: 1)
Case Reports in Ophthalmological Medicine     Open Access   (Followers: 3)
Case Reports in Orthopedics     Open Access   (Followers: 6)
Case Reports in Otolaryngology     Open Access   (Followers: 7)
Case Reports in Pathology     Open Access   (Followers: 7)
Case Reports in Pediatrics     Open Access   (Followers: 8)
Case Reports in Psychiatry     Open Access   (Followers: 18)
Case Reports in Pulmonology     Open Access   (Followers: 3)
Case Reports in Radiology     Open Access   (Followers: 12)
Case Reports in Rheumatology     Open Access   (Followers: 10)
Case Reports in Surgery     Open Access   (Followers: 12)
Case Reports in Transplantation     Open Access  
Case Reports in Urology     Open Access   (Followers: 12)
Case Reports in Vascular Medicine     Open Access  
Case Reports in Veterinary Medicine     Open Access   (Followers: 5)
Child Development Research     Open Access   (Followers: 21, SJR: 0.144, CiteScore: 0)
Chinese J. of Engineering     Open Access   (Followers: 2, SJR: 0.114, CiteScore: 0)
Chinese J. of Mathematics     Open Access  
Chromatography Research Intl.     Open Access   (Followers: 5)
Complexity     Hybrid Journal   (Followers: 8, SJR: 0.531, CiteScore: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2, SJR: 0.403, CiteScore: 1)
Computational Biology J.     Open Access   (Followers: 7)
Computational Intelligence and Neuroscience     Open Access   (Followers: 15, SJR: 0.326, CiteScore: 1)
Concepts in Magnetic Resonance Part A     Open Access   (Followers: 1, SJR: 0.354, CiteScore: 1)
Concepts in Magnetic Resonance Part B, Magnetic Resonance Engineering     Open Access   (Followers: 1, SJR: 0.26, CiteScore: 1)
Conference Papers in Science     Open Access   (Followers: 2)
Contrast Media & Molecular Imaging     Open Access   (Followers: 2, SJR: 0.842, CiteScore: 3)
Critical Care Research and Practice     Open Access   (Followers: 13, SJR: 0.499, CiteScore: 1)
Current Gerontology and Geriatrics Research     Open Access   (Followers: 10, SJR: 0.512, CiteScore: 2)
Depression Research and Treatment     Open Access   (Followers: 19, SJR: 0.816, CiteScore: 2)
Dermatology Research and Practice     Open Access   (Followers: 4, SJR: 0.806, CiteScore: 2)
Diagnostic and Therapeutic Endoscopy     Open Access   (SJR: 0.201, CiteScore: 1)
Discrete Dynamics in Nature and Society     Open Access   (Followers: 6, SJR: 0.279, CiteScore: 1)
Disease Markers     Open Access   (Followers: 1, SJR: 0.9, CiteScore: 2)
Economics Research Intl.     Open Access   (Followers: 1)
Education Research Intl.     Open Access   (Followers: 19)
Emergency Medicine Intl.     Open Access   (Followers: 9, SJR: 0.298, CiteScore: 1)
Enzyme Research     Open Access   (Followers: 5, SJR: 0.653, CiteScore: 3)
Evidence-based Complementary and Alternative Medicine     Open Access   (Followers: 30, SJR: 0.683, CiteScore: 2)
Game Theory     Open Access   (Followers: 1)
Gastroenterology Research and Practice     Open Access   (Followers: 1, SJR: 0.768, CiteScore: 2)
Genetics Research Intl.     Open Access   (Followers: 1, SJR: 0.61, CiteScore: 2)
Geofluids     Open Access   (Followers: 5, SJR: 0.952, CiteScore: 2)
Hepatitis Research and Treatment     Open Access   (Followers: 6, SJR: 0.389, CiteScore: 2)
Heteroatom Chemistry     Open Access   (Followers: 3, SJR: 0.333, CiteScore: 1)
HPB Surgery     Open Access   (Followers: 9, SJR: 0.824, CiteScore: 2)
Infectious Diseases in Obstetrics and Gynecology     Open Access   (Followers: 5, SJR: 1.27, CiteScore: 2)
Interdisciplinary Perspectives on Infectious Diseases     Open Access   (Followers: 1, SJR: 0.627, CiteScore: 2)
Intl. J. of Aerospace Engineering     Open Access   (Followers: 80, SJR: 0.232, CiteScore: 1)
Intl. J. of Agronomy     Open Access   (Followers: 6, SJR: 0.311, CiteScore: 1)
Intl. J. of Alzheimer's Disease     Open Access   (Followers: 12, SJR: 0.787, CiteScore: 3)
Intl. J. of Analytical Chemistry     Open Access   (Followers: 22, SJR: 0.285, CiteScore: 1)
Intl. J. of Antennas and Propagation     Open Access   (Followers: 13, SJR: 0.233, CiteScore: 1)
Intl. J. of Atmospheric Sciences     Open Access   (Followers: 21)
Intl. J. of Biodiversity     Open Access   (Followers: 3)
Intl. J. of Biomaterials     Open Access   (Followers: 5, SJR: 0.511, CiteScore: 2)
Intl. J. of Biomedical Imaging     Open Access   (Followers: 3, SJR: 0.501, CiteScore: 2)
Intl. J. of Breast Cancer     Open Access   (Followers: 14, SJR: 1.025, CiteScore: 2)
Intl. J. of Cell Biology     Open Access   (Followers: 4, SJR: 1.887, CiteScore: 4)
Intl. J. of Chemical Engineering     Open Access   (Followers: 8, SJR: 0.327, CiteScore: 1)
Intl. J. of Chronic Diseases     Open Access   (Followers: 1)
Intl. J. of Combinatorics     Open Access   (Followers: 1)
Intl. J. of Computer Games Technology     Open Access   (Followers: 10, SJR: 0.287, CiteScore: 2)
Intl. J. of Corrosion     Open Access   (Followers: 11, SJR: 0.194, CiteScore: 1)
Intl. J. of Dentistry     Open Access   (Followers: 8, SJR: 0.649, CiteScore: 2)
Intl. J. of Differential Equations     Open Access   (Followers: 8, SJR: 0.191, CiteScore: 0)
Intl. J. of Digital Multimedia Broadcasting     Open Access   (Followers: 5, SJR: 0.296, CiteScore: 2)
Intl. J. of Electrochemistry     Open Access   (Followers: 10)
Intl. J. of Endocrinology     Open Access   (Followers: 4, SJR: 1.012, CiteScore: 3)
Intl. J. of Engineering Mathematics     Open Access   (Followers: 7)
Intl. J. of Food Science     Open Access   (Followers: 5, SJR: 0.44, CiteScore: 2)
Intl. J. of Forestry Research     Open Access   (Followers: 3, SJR: 0.373, CiteScore: 1)
Intl. J. of Genomics     Open Access   (Followers: 2, SJR: 0.868, CiteScore: 3)
Intl. J. of Geophysics     Open Access   (Followers: 5, SJR: 0.182, CiteScore: 1)
Intl. J. of Hepatology     Open Access   (Followers: 4, SJR: 0.874, CiteScore: 2)
Intl. J. of Hypertension     Open Access   (Followers: 8, SJR: 0.578, CiteScore: 1)
Intl. J. of Inflammation     Open Access   (SJR: 1.264, CiteScore: 3)
Intl. J. of Inorganic Chemistry     Open Access   (Followers: 4)
Intl. J. of Manufacturing Engineering     Open Access   (Followers: 2)
Intl. J. of Mathematics and Mathematical Sciences     Open Access   (Followers: 3, SJR: 0.177, CiteScore: 0)
Intl. J. of Medicinal Chemistry     Open Access   (Followers: 6, SJR: 0.31, CiteScore: 1)
Intl. J. of Metals     Open Access   (Followers: 7)
Intl. J. of Microbiology     Open Access   (Followers: 8, SJR: 0.662, CiteScore: 2)
Intl. J. of Microwave Science and Technology     Open Access   (Followers: 6, SJR: 0.136, CiteScore: 1)
Intl. J. of Navigation and Observation     Open Access   (Followers: 20, SJR: 0.267, CiteScore: 2)
Intl. J. of Nephrology     Open Access   (Followers: 2, SJR: 0.697, CiteScore: 1)
Intl. J. of Oceanography     Open Access   (Followers: 8)
Intl. J. of Optics     Open Access   (Followers: 10, SJR: 0.231, CiteScore: 1)
Intl. J. of Otolaryngology     Open Access   (Followers: 3)
Intl. J. of Partial Differential Equations     Open Access   (Followers: 2)
Intl. J. of Pediatrics     Open Access   (Followers: 6)
Intl. J. of Peptides     Open Access   (Followers: 2, SJR: 0.46, CiteScore: 1)
Intl. J. of Photoenergy     Open Access   (Followers: 3, SJR: 0.341, CiteScore: 1)
Intl. J. of Plant Genomics     Open Access   (Followers: 4, SJR: 0.583, CiteScore: 1)
Intl. J. of Polymer Science     Open Access   (Followers: 28, SJR: 0.298, CiteScore: 1)
Intl. J. of Population Research     Open Access   (Followers: 4)
Intl. J. of Quality, Statistics, and Reliability     Open Access   (Followers: 17)
Intl. J. of Reconfigurable Computing     Open Access   (SJR: 0.123, CiteScore: 1)
Intl. J. of Reproductive Medicine     Open Access   (Followers: 6)
Intl. J. of Rheumatology     Open Access   (Followers: 4, SJR: 0.645, CiteScore: 2)
Intl. J. of Rotating Machinery     Open Access   (Followers: 2, SJR: 0.193, CiteScore: 1)
Intl. J. of Spectroscopy     Open Access   (Followers: 8)
Intl. J. of Stochastic Analysis     Open Access   (Followers: 3, SJR: 0.279, CiteScore: 1)
Intl. J. of Surgical Oncology     Open Access   (Followers: 1, SJR: 0.573, CiteScore: 2)
Intl. J. of Telemedicine and Applications     Open Access   (Followers: 7, SJR: 0.403, CiteScore: 2)
Intl. J. of Vascular Medicine     Open Access   (SJR: 0.782, CiteScore: 2)
Intl. J. of Zoology     Open Access   (Followers: 2, SJR: 0.209, CiteScore: 1)
Intl. Scholarly Research Notices     Open Access   (Followers: 230)

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Similar Journals
Journal Cover
Advances in Polymer Technology
Journal Prestige (SJR): 0.299
Citation Impact (citeScore): 1
Number of Followers: 14  

  This is an Open Access Journal Open Access journal
ISSN (Print) 0730-6679 - ISSN (Online) 1098-2329
Published by Hindawi Homepage  [343 journals]
  • Scalable Electrochemical Synthesis of Novel Biogenic Silver Nanoparticles
           and Its Application to High-Sensitive Detection of 4-Nitrophenol in
           Aqueous System

    • Abstract: This study reports a scalable green electrochemical synthesis of novel biogenic silver nanoparticles colloid (biogenic AgNPs) in large scale up to 5 liters using the bulk silver bar and the green tea leaves (Camellia sinensis) extract (GTE) as reducing agent during the electrochemical process. Under a direct-current voltage source, the biomolecules in GTE can release electrons to promote the reducing process of Ag+ to Ag0. More interestingly, the formation of the intermediate complex helps to cap on the nanoparticles, which leads to stabilizing AgNPs. The as-synthesized biogenic AgNPs with the size of 34 nm exhibit the outstanding electrochemical properties due to the presence of biomolecules on the biogenic AgNPs surface, which facilitates the effective attaching of AgNPs on the carbon surface of the screen-printed carbon electrode (SPE) through the formation of the strong C-O coordinate bonds between O atom of oxygen functional groups and C atom of SPE. The electrochemical properties of the biogenic AgNPs-modified SPE are enhanced significantly in comparison with bare SPE and pure AgNPs-SPE. The biogenic AgNPs-SPE is applied successfully to the detection of 4-nitrophenol (4-NP). The electrochemical sensor using biogenic AgNPs can reliably detect 4-NP in the linear range from 0.1 to 25 μM with the sensitivity about 6.69 μA μM-1 cm-2. The present work reveals, as the greener synthesis method with ultra-large scalable ability, high purity, and excellent electrochemical properties of biogenic AgNPs is very promising for technological applications in high-sensitive electrochemical chemosensors, nanopharmaceuticals, and other fields.
      PubDate: Mon, 18 Jan 2021 07:50:01 +000
       
  • Supramolecular Biopolymers for Tissue Engineering

    • Abstract: Supramolecular biopolymers (SBPs) are those polymeric units derived from macromolecules that can assemble with each other by noncovalent interactions. Macromolecular structures are commonly found in living systems such as proteins, DNA/RNA, and polysaccharides. Bioorganic chemistry allows the generation of sequence-specific supramolecular units like SBPs that can be tailored for novel applications in tissue engineering (TE). SBPs hold advantages over other conventional polymers previously used for TE; these materials can be easily functionalized; they are self-healing, biodegradable, stimuli-responsive, and nonimmunogenic. These characteristics are vital for the further development of current trends in TE, such as the use of pluripotent cells for organoid generation, cell-free scaffolds for tissue regeneration, patient-derived organ models, and controlled delivery systems of small molecules. In this review, we will analyse the 3 subtypes of SBPs: peptide-, nucleic acid-, and oligosaccharide-derived. Then, we will discuss the role that SBPs will be playing in TE as dynamic scaffolds, therapeutic scaffolds, and bioinks. Finally, we will describe possible outlooks of SBPs for TE.
      PubDate: Wed, 13 Jan 2021 15:05:00 +000
       
  • The Effect of Multiwalled Carbon Nanotubes on the Thermal Conductivity and
           Cellular Size of Polyurethane Foam

    • Abstract: Polyurethane (PU) foam is known as the popular material for the applications in many fields of industry and life. To improve the mechanical and thermal properties of this material, in this research, PU foam was reinforced with aniline-modified multiwalled carbon nanotubes (MWCNTs). Fourier transform infrared FTIR spectrum of modified MWCNTs showed the aniline was grafted on the surface of MWCNTs through the appearance of –NH2 stretches. The effect of MWCNTs with and without modification on the density, porosity, compressive strength, and heat conductivity of PU/MWCNT foam nanocomposites was investigated. The dispersibility of MWCNTs in the PU matrix was enhanced after modification with aniline. Compressive strength of PU nanocomposite reached the highest value after adding 3 wt.% of modified MWCNTs into PU foam. Besides, the water uptake of PU nanocomposites using 3 wt.% of MWCNTs was decreased to 13.4% as compared to that using unmodified MWCNTs. The improvement in thermal conductivity of PU/aniline-modified MWCNT nanocomposite was observed due to the change in the cellular size of PU foam in the presence of MWCNTs as shown by SEM images.
      PubDate: Wed, 06 Jan 2021 07:50:01 +000
       
  • Semi-interpenetrating Network Membrane from Polyethyleneimine-Epoxy Resin
           and Polybenzimidazole for HT-PEM Fuel Cells

    • Abstract: In the present work, a semi-interpenetrating network (semi-IPN) high-temperature proton exchange membrane based on polyethyleneimine (PEI), epoxy resin (ER), and polybenzimidazole (PBI) was prepared and characterized, aiming at their future application in fuel cell devices. The physical properties of the semi-IPN membrane are characterized by thermogravimetric analysis (TGA) and tensile strength test. The results indicate that the as-prepared PEI-ER/PBI semi-IPN membranes possess excellent thermal stability and mechanical strength. After phosphoric acid (PA) doping treatment, the semi-IPN membranes show high proton conductivities. PA doping level and volume swelling ratio as well as proton conductivities of the semi-IPN membranes are found to be positively related to the PEI content. High proton conductivities of are achieved at 160°C for these PA-doped PEI-ER/PBI series membranes. H2/O2 fuel cell assembled with PA-doped PEI-ER(1 : 2)/PBI membrane delivered a peak power density of 170 mW cm-2 at 160°C under anhydrous conditions.
      PubDate: Wed, 30 Dec 2020 08:05:01 +000
       
  • Development and Performance Evaluation of Cellulose Acetate-Bentonite
           Mixed Matrix Membranes for CO2 Separation

    • Abstract: Membrane science is a state-of-the-art environmentally green technology that ascertains superior advantages over traditional counterparts for CO2 capture and separation. In this research, mixed matrix membranes (MMMs) comprising cellulose acetate (CA) with various loadings of bentonite (Bt) clay were fabricated by adopting the phase-inversion technique for CO2/CH4 and CO2/N2 separation. The developed pristine and MMMs were characterized for morphological, thermal, structural, and mechanical analyses. Several techniques such as scanning electron microscopy, thermogravimetric analysis, Fourier transformed infrared spectroscopy, and nano-indentation investigations revealed the promising effect of Bt clay in MMMs as compared to pristine CA membrane. Nano-indentation test identified that elastic modulus and hardness of the MMM with 1 wt. loading was increased by 64% and 200%, respectively, compared to the pristine membrane. The permeability decreased with the incorporation of Bt clay due to uniform dispersion of filler attributed to enhanced tortuosity for the gas molecules. Nevertheless, an increase in gas separation performance was observed with Bt addition up to 1 wt. loading. The opposite trend prevailed with increasing Bt concentration on the separation performance owing to filler agglomeration and voids creation. The maximum value of ideal selectivity (CO2/CH4) was achieved at 2 bar pressure with 1 wt. % Bt loading, which is 79% higher than the pristine CA membrane. For CO2/N2, the ideal selectivity was 123% higher compared to the pristine membrane with 1 wt. % Bt loading at 4 bar pressure.
      PubDate: Mon, 14 Dec 2020 04:35:01 +000
       
  • Study of Residual Wall Thickness and Multiobjective Optimization for
           Process Parameters of Water-Assisted Injection Molding

    • Abstract: Residual wall thickness is an important indicator for water-assisted injection molding (WAIM) parts, especially the maximization of hollowed core ratio and minimization of wall thickness difference which are significant optimization objectives. Residual wall thickness was calculated by the computational fluid dynamics (CFD) method. The response surface methodology (RSM) model, radial basis function (RBF) neural network, and Kriging model were employed to map the relationship between process parameters and hollowed core ratio, and wall thickness difference. Based on the comparison assessments of the three surrogate models, multiobjective optimization of hollowed core ratio and wall thickness difference for cooling water pipe by integrating design of experiment (DOE) of optimized Latin hypercubes (Opt LHS), RBF neural network, and particle swarm optimization (PSO) algorithm was studied. The research results showed that short shot size, water pressure, and melt temperature were the most important process parameters affecting hollowed core ratio, while the effects of delay time and mold temperature were little. By the confirmation experiments for the best solution resulted from the Pareto frontier, the relative errors of hollowed core ratio and wall thickness are 2.2% and 3.0%, respectively. It demonstrated that the proposed hybrid optimization methodology could increase hollowed core ratio and decrease wall thickness difference during the WAIM process.
      PubDate: Fri, 11 Dec 2020 07:50:02 +000
       
  • Peroxymonosulfate Activation on a Hybrid Material of Conjugated PVC and
           TiO2 Nanotubes for Enhancing Degradation of Rhodamine B under Visible
           Light

    • Abstract: Visible-light-driven photocatalysis is a robust technology for amending the negative effect of pollutants on the environment with a minimum energy use. Herein, we describe a simple approach to producing such a photocatalyst by coupling conjugated polyvinyl chloride (cPVC) with the TiO2 nanotube (TNT) thermolysis method. By activating peroxymonosulfate (PMS) to make a cPVC/TNT/PMS system using visible light as the source, we obtain a significant enhancement in the photocatalytic performance. We show that PMS use at a concentration of 3 mM can fully degrade rhodamine B (RhB) solution at a remarkably high concentration (200 mg L-1) just in 120 min under visible light. The cPVC/TNT/PMS system also shows excellent stability in recycling tests for at least five times. Further, by confining the active species in photocatalytic reactions, we report a thorough understanding of the extent of involvement from those radicals. Our work presents a robust approach to make a high-performance, visible-light-driven photocatalyst, which can be potentially used in practice.
      PubDate: Thu, 26 Nov 2020 06:50:01 +000
       
  • Effect Of Magnesium Perchlorate Content on the Mechanical, Thermal
           Stability, and Dielectric Properties of Plasticized PMMA/PVC-g-PMMA
           Electrolytes

    • Abstract: In this study, new types of gel polymer blend electrolytes (GPBEs) were prepared with the synthesized PVC-g-PMMA graft copolymer, PMMA, plasticizers (propylene carbonate (PC), dioctyl phthalate (DOP)), and different loadings of Mg(ClO4)2 via the solution casting method using tetrahydrofuran as solvent. Fourier transform infrared (FTIR) spectra of the electrolytes showed mutual molecular interactions between Mg(ClO4)2 and organic moieties. The scanning electron microscopy images of the GPBEs showed their wrinkled surface morphology due to their low elastic modulus and high flexibility. Energy-dispersive X-ray (EDX) spectroscopy and mapping technique revealed the regular distributions of all atomic elements such as Cl, Mg, O, and C in the doped GPBEs. With increasing the Mg salt concentration, Young’s modulus and tensile strength of the GPBEs strongly decreased. Interestingly, the elongation at break of the GPBEs was higher than that of neat (undoped) GPBE and achieved the highest value of 215% at the salt content of 20 wt.%. The AC conductivity and ionic conductivity, as well as dielectric permittivity of plasticized PMMA/PVC-g-PMMA/Mg(ClO4)2 GPBE,s increased with frequency and Mg(ClO4)2 doping content. Ionic conductivity of the doped GPBEs can be achieved from to (S.cm-1) using Mg(ClO4)2 contents in the range from 10 to 40 wt.%. The doped GPBEs are thermally stable up to 100°C with very low weight losses. The GPBE doped with 20 wt.% of Mg(ClO4)2 can be used as a new type of electrolyte for developing Mg batteries.
      PubDate: Mon, 16 Nov 2020 13:20:00 +000
       
  • GC-FID and Olfactometry-Assisted Assessment of Odors from Polymeric Foams
           under Normal and Repeated-Use Conditions

    • Abstract: Polymeric foams are the primary components of upholstered furniture, and their emissions play a decisive role in the acceptability of the final furniture product. This study is focused on passive emissions and odors from commercial foams under normal and repeated-use conditions. Six different types of foams, viz., highly elastic foam K5040, standard PU foam N5063, bonded polyurethane foam R100, viscoelastic foam V5020, self-extinguishing foam KF5560, and foam rubber, were used. The samples were collected at the intervals of 72 hours and 672 hours (28 days) to identify the odors due to chemical reactions in the material or slowly released due to its porous structure. Additionally, repeated-use studies were done to understand the effect of prolonged usage/natural ageing on emitted odors from the foams. The samples were tested as per ČSN EN 13 725 (2005) and ISO 16000-6 (2011) criteria using GC-FID (gas chromatography-flame ionization detector) and olfactometry. The most unpleasant substance was found to be nonanal, with an average score of -4 (unpleasant). A total of 23 compounds were identified (5 unidentified) using olfactometry; however, only 11 of them were confirmed by GC-FID-based testing. Any new compound or increase in odor intensity was not observed in long-term measurements and simulated repeated-use conditions.
      PubDate: Mon, 09 Nov 2020 13:35:00 +000
       
  • Ductile to Brittle Transition of Short Carbon Fiber-Reinforced
           Polypropylene Composites

    • Abstract: In this work, the ductile to brittle transition behavior of short carbon fiber (SCF)-reinforced polypropylene (PP) composite is studied. Initially, the SCF-reinforced PP composites with a varying composition of SCF in the range of 0–40 wt% loading were first melt-mixed in a twin-screw extruder and later injection-molded to produce the testing samples. The experimental results indicate that with an increase in SCF loading, an increase in the tensile modulus and strength was observed along with a rapid decrease in the values of strain at break. A sudden decrease in strain at break was observed in composites in the range of 10–15 wt% SCF. To further study the sudden decrease in strain at break, an investigation was performed on composites that contained 10–15 wt% of SCF loading, starting from 10 wt% with a 1% increment to 15 wt% of SCF. The results of this study show that a decrease in strain at break was not linear; on the contrary, it was accompanied by a ductile to brittle transition, which specifically occurred in the range of 12–13 wt% of SCF loading and then continued to decrease with an increase in SCF loading.
      PubDate: Thu, 05 Nov 2020 08:20:00 +000
       
  • The Effect of PVP Molecular Weight on Dissolution Behavior and
           

    • Abstract: The effect of polyvinylpyrrolidone (PVP) as glycyrrhetic acid (GA) solid dispersions carrier at different molecular weights on the dissolution behavior and physicochemical properties was investigated. PVP-GA-SDs prepared with all four molecular weight PVPs displayed good enhancement of dissolution rate and equilibrium solubility compared with pure drug and corresponding physical mixtures. The results showed that the enhancement effect of molecular weight on dissolution rate and equilibrium solubility follows . In addition, the dissolution rate and solubility of the SDs with a carrier-drug ratio of 8 : 1 were better than the samples of 4 : 1. The DSC and XRD patterns showed that the crystallization of GA in SDs prepared by PVP K30 and PVP K60 was significantly inhibited, and both were transformed to amorphous. Based on FTIR and Raman detection, a hydrogen-bond between PVP and drug molecules is formed. SEM results showed that there were no significant differences in the appearance of SDs prepared with four PVPs, and no crystalline morphology of GA was seen. In conclusion, the findings of this study demonstrated that the dissolution performance of the PVP-GA-SDs prepared by the solvent method is related to the molecular weight of PVP, and the change in the molecular weight of PVP does not cause a monotonic change in dissolution of GA. The samples with PVP K30 as the carrier have the best dissolution performance.
      PubDate: Sat, 31 Oct 2020 12:35:00 +000
       
  • Experimental and Numerical Study Determining the Warpage Phenomenon of
           Thin-Wall Injection Molding

    • Abstract: This study emphasizes the warpage phenomenon of thin-walled parts using acrylonitrile-butadiene styrene (ABS) plus polycarbonate (PC) plastics for optimal processing by thin-wall injection molding. The authors first employed the Moldflow software to analyze the runner’s balance on multicavities for thin-walled parts and to simulate the warpage of thin-walled parts with thin-wall injection molding. Then, this study used those data to fabricate a real mold by computer numerical control machining. For this study, the authors fabricated thin-walled parts and measured their warpage using various process parameters (injection speed, injection pressure, mold temperature, packing time, and melt temperature) with thin-walled injection molding. Finally, the authors found that the most important processing parameter was the packing time for warpage phenomenon of thin-walled parts by thin-wall injection molding.
      PubDate: Wed, 28 Oct 2020 05:20:01 +000
       
  • Preparation and Characterization of Liposomal Everolimus by Thin-Film
           Hydration Technique

    • Abstract: In 10% to 40% of the cases of coronary stent implantation, patients face in-stent restenosis due to an inflammatory response, which induces artery thickening. Everolimus, a drug that inhibits growth factor-stimulated cell proliferation of endothelial cells, represents a promising alternative to prevent in-stent restenosis. In this study, everolimus was encapsulated by a film hydration technique in liposomes by using phosphatidylcholine and cholesterol at different ratios. As the ratio of cholesterol increases, it modulates the rigidity of the structure which can affect the encapsulation efficiency of the drug due to steric hindrance. Moreover, various lipid : drug ratios were tested, and it was found that as the lipid : drug ratio increases, the encapsulation efficiency also increases. This behavior is observed because everolimus is a hydrophobic drug; therefore, if the lipidic region increases, more drug can be entrapped into the liposomes. In addition, stability of the encapsulated drug was tested for 4 weeks at 4°C. Our results demonstrate that it is possible to prepare liposomal everolimus by film hydration technique followed by extrusion with high entrapment efficiency as a viable drug delivery system.
      PubDate: Sat, 10 Oct 2020 08:20:01 +000
       
  • Studies on Hydration Swelling and Bound Water Type of Sodium- and
           Polymer-Modified Calcium Bentonite

    • Abstract: Modified calcium bentonite (Ca-bentonite) is extensively used in engineered barrier systems (EBSs) for municipal and industrial disposal sites due to its high swelling potential and low hydraulic conductivity. However, few studies have focused on the micromechanism of hydration and swelling under the effect of inorganic chemical solution. In this study, free swell index (FSI) and the type and content of modified Ca-bentonite bound water under the inorganic chemical solution were quantitatively studied by using the free swell test and nuclear magnetic resonance (NMR). According to the results, modification of sodium and polymer significantly increases the FSI of Ca-bentonite, bringing it close to that of natural sodium bentonite. In addition, the chemical stability of polymer-modified bentonite is significantly higher than that of sodium-modified bentonite but less than that of natural Na-bentonite. The FSI of modified Ca-bentonite decreases with the increase of cation valence and ionic strength. distribution curves of the two types of modified bentonite are three-peak curves. With the increase of ionic strength, the content of total water and permeated hydrated water (accounting for 69%–95%) in bentonite decreases gradually, whereas the surface hydration water (accounting for 2%–31%) and free water content (accounting for 0–15%) increase. A uniform linear relationship exists between the FSI and corresponding total peak area of NMR (independent of ion valence, concentration, and bentonite type). Furthermore, a linear relationship exists between the FSI of the same type of bentonite and the relaxation time. Research results can provide data and theoretical basis for quantitative analysis and mechanism of the hydration swelling of bentonite.
      PubDate: Fri, 09 Oct 2020 08:35:00 +000
       
  • Metal-Organic Framework MIL-53(Fe): Synthesis, Electrochemical
           Characterization, and Application in Development of a Novel and Sensitive
           

    • Abstract: A metal-organic framework MIL-53(Fe) was successfully synthesized by a simple hydrothermal method. A synthesized MIL-53(Fe) sample was characterized, and results indicated that the formed MIL-53(Fe) was a single phase with small particle size of 0.8 μm and homogeneous particle size distribution was obtained. The synthesized MIL-53(Fe) has been used to modify a glassy carbon electrode (GCE) by a drop-casting technique. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements of the MIL-53(Fe)-modified GCE showed that the MIL-53(Fe) was successfully immobilized onto the GCE electrode surface and the electrochemical behavior of the GCE/MIL-53(Fe) electrode was stable. In addition, several electrochemical parameters of MIL-53(Fe)-modified GCE (GCE/MIL-53(Fe)) including the heterogeneous standard rate constant () and the electrochemically effective surface area () were calculated. Obtained results demonstrated that the synthesized MIL-53(Fe) with the small particle size, highly homogeneous particle size, and high electrochemically effective surface area was able to significantly enhance the electrochemical response signal of the working electrode. Therefore, the GCE/MIL-53(Fe) electrode has been used as a highly sensitive electrochemical sensor for cadmium ion (Cd(II)) monitoring in aqueous solution using differential pulse voltammetry (DPV) technique. The response signal of the electrochemical sensor increased linearly in the Cd(II) ion concentration range from 150 nM to 450 nM with the limit of detection (LOD) of 16 nM.
      PubDate: Tue, 06 Oct 2020 13:35:01 +000
       
  • Study of Raw and Recycled Polyethylene Terephthalate by Meaning of TGA and
           Computer Simulation

    • Abstract: The pyrolysis method of both raw and recycled polyethylene terephthalate was studied using the nonisothermal thermogravimetric analysis (TGA) at different five heating rates (10, 15, 20, 25, and 30 K/min) for each element. Without using any mathematical equations, the kinetic parameters of polyethylene terephthalate pyrolysis were obtained by applying the modified distributed activation energy model (DAEM). Furthermore, the glass transition temperature (Tg) of polyethylene terephthalate was simulated using the computer simulation with different methods. The effect of energy in the Tg process was enhanced. The mechanical properties of polyethylene terephthalate were computed. Our simulated values were compared with available data in literature.
      PubDate: Mon, 05 Oct 2020 06:20:01 +000
       
  • Transpicuous-Cum-Fouling Resistant Copolymers of 3-Sulfopropyl
           Methacrylate and Methyl Methacrylate for Optronics Applications in Aquatic
           Medium and Healthcare

    • Abstract: The scope of optical sensors and scanners in aquatic media, fluids, and medical diagnostics has been limited by paucity of transparent shielding materials with antifouling potential. In this research endeavor, facile synthesis, characterization, and bioassay of antifouling transparent functional copolymers are reported. Copolymers of 3-sulfopropyl methacrylate (SPMA) and methyl methacrylate (MMA) were synthesized by free radical polymerization in various proportions. Samples PSM20, PSM30, PSM40, PSM50, and PSM60 contain 20%, 30%, 40%, 50%, and 60% SPMA by weight, respectively. Resultant products were characterized by FTIR and 1H-NMR spectroscopy. The synthesized copolymers have exhibited excellent transparency, i.e., 75% to 88%, as determined by the UV-Vis spectroscopic analysis. Transmittance was decreased from 6% to 2% in these copolymers upon changing the concentration of 3-sulfopropyl methacrylate from 20% to 50% owing to bacterial and algal biofilm formation. Water contact angle values were ranged from 18° to 63° and decreased with the increase in the polarity of copolymers. The surface energy lowest value 58 mJ/m2 and highest value 72 mJ/m2 were calculated for PSM20 and PSM50, respectively, by the Chibowski approach and Young equation. Sample PSM50 has exhibited the highest antibacterial activities, i.e., 18 mm and 19 mm, against Escherichia coli and Staphylococcus aureus, respectively, by the disk diffusion method. Copolymer PSM50 has shown minimum algal adhesion for Dictyosphaerium algae as observed by optical microscopy. This lower bacterial and algal adhesion is attributed to higher concentrations of anionic SPMA monomer that cause electrostatic repulsion between functional groups of the polymer and microorganisms. Thus, the resultant PSM50 product has exhibited good potential for optronics shielding application in aquatic medium and medical diagnostics.
      PubDate: Mon, 05 Oct 2020 06:05:00 +000
       
  • RAFT Copolymerization of Styrene and Maleic Anhydride with Addition of
           Ascorbic Acid at Ambient Temperature

    • Abstract: A novel method for RAFT copolymerization of styrene (St) and maleic anhydride (MAh) at ambient temperature using ascorbic acid (Asc) as an initiator is reported. Various experimental conditions including reaction component, monomer composition, the amount of Asc, and temperature were investigated in terms of monomer conversion, molecular weight, and molecular weight distribution. In this system, the copolymer of styrene/maleic anhydride (SMA) with well-regulated molecular weight and low molecular weight distribution () was obtained, and the conversion of monomer was 70.4% after 12 hours at 25°C. The NMR spectra demonstrated that the copolymer synthesized possesses a strictly alternating structure. Furthermore, the proposed mechanism adapted to the RAFT copolymerization of St and MAh initiated by Asc at ambient temperature is presented. Using this new methodology, it is possible to achieve well-defined SMA under mild conditions by RAFT copolymerization.
      PubDate: Fri, 25 Sep 2020 08:05:01 +000
       
  • Self-Healing Polyurethane-Based Nanocomposites Modified with Carbon Fibres
           and Carbon Nanotubes

    • Abstract: Self-healing polyurethanes (PUs) were synthesized as a matrix of nanocomposites containing two fibrous carbon components, i.e., functionalized carbon nanotubes (CNF-OH) and short carbon fibers (CF). Two types of PUs differing in the content of flexible chain segments (40% and 50%) were used. Changes in mechanical strength were analyzed to assess the ability to self-healing of PU-based matrix nanocomposites with experimentally introduced damage in the form of an incision. The healing process was activated by heating the damaged samples at 60°C, for 30 minutes. The addition of CNT-OH and CF caused a slight reduction in the self-healing ability of the nanocomposites as compared to the neat PUs. After heating to 60°C, the nanocomposites self-healed up to 72% of the initial strength of the undamaged samples. The introduction of fibrous components to the polymer matrix improved the thermal conductivity of nanocomposites and facilitated heat transfer from the environment to the interior of the samples, necessary to initiate self-healing. Low content of carbon components in the PU matrix, i.e., 3 wt% of CF and 2 wt% of CNF-OH increased the total work up to fracture of samples after healing by about 53%.
      PubDate: Sun, 30 Aug 2020 07:35:00 +000
       
  • Polymer Technology for the Detection and Elimination of Emerging
           Pollutants

    • PubDate: Wed, 26 Aug 2020 13:50:02 +000
       
  • Chitosan-Reinforced MFC/NFC Aerogel and Antibacterial Property

    • Abstract: MFC/NFC aerogel has water sensitivity, and it should be improved in strength in water before application. Chitosan was investigated as a MFC/NFC aerogel reinforcing agent in this paper. The reinforced aerogel showed slightly tighter structure and very good water stability and mechanical strength. FTIR disclosed the chemical bonds formed between chitosan and cellulose. Nanoparticles of silver (Ag-NPs) were loaded using the reinforced aerogel. The excellent Ag-NP monodistribution on the aerogel was expressed by TEM. Both chitosan-reinforced Ag-NPs loaded MFC aerogel and NFC aerogel and expressed great antibacterial activity, though reinforced MFC aerogel exhibited better properties, like higher BET, lighter density, more Ag-NP loading, and better distribution, than NFC aerogel in this research. Chitosan-reinforced MFC aerogel is a good potential substrate for nanoparticle loading and biocomposite making.
      PubDate: Wed, 26 Aug 2020 11:20:02 +000
       
  • Nonisothermal Kinetic Analysis and AC Conductivity for Polyvinyl Chloride
           (PVC)/Zinc Oxide (ZnO) Nanocomposite

    • Abstract: The behavior of polyvinyl chlorine (PVC)/zinc oxide (ZnO) nanoparticles was investigated. To improve the dispersion and distribution of zinc nanoparticles within the host polymer (PVC), they were treated with water before being added to the polymer. The nanocomposite samples were prepared by casting method using different weight ratios of ZnO nanoparticles. The prepared nanocomposite samples were characterized by thermogravimetric analysis (TGA). Both thermal stability and kinetic analysis of the prepared samples were investigated. The ZnO nanoparticles lower the activation energy and decrease the thermal stability of PVC. Kissinger, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose models were used in the nonisothermal kinetic analysis of PVC/ZnO nanocomposite samples. The thermal stability behavior due to the addition of zinc oxide nanoparticles was explained and correlated with the behavior of the kinetic parameters of the samples. The AC conductivity as function of frequency and temperature was also investigated. The addition of ZnO nanoparticle increases the AC conductivity, and the temperature-independent region decreased by increasing temperature. Both and coefficients were predicted using the Jonscher power law and OriginLab software. The trends of and coefficients were discussed based on the glass transition of the host polymer.
      PubDate: Mon, 17 Aug 2020 14:35:03 +000
       
  • 3D Network Structural Poly (Aryl Ether Ketone)-Polybenzimidazole Polymer
           for High-Temperature Proton Exchange Membrane Fuel Cells

    • Abstract: Poor mechanical property is a critical problem for phosphoric acid-doped high-temperature proton exchange membranes (HT-PEMs). In order to address this concern, in this work, a 3D network structural poly (aryl ether ketone)-polybenzimidazole (PAEK-cr-PBI) polymer electrolyte membrane was successfully synthesized through crosslinking reaction between poly (aryl ether ketone) with the pendant carboxyl group (PAEK-COOH) and amino-terminated polybenzimidazole (PBI-4NH2). PAEK-COOH with a poly (aryl ether ketone) backbone endows superior thermal, mechanical, and chemical stability, while PBI-4NH2 serves as both a proton conductor and a crosslinker with basic imidazole groups to absorb phosphoric acid. Moreover, the composite membrane of PAEK-cr-PBI blended with linear PBI (PAEK-cr-PBI@PBI) was also prepared. Both membranes with a proper phosphoric acid (PA) uptake exhibit an excellent proton conductivity of around 50 mS cm-1 at 170°C, which is comparable to that of the well-documented PA-doped PBI membrane. Furthermore, the PA-doped PAEK-cr-PBI membrane shows superior mechanical properties of 17 MPa compared with common PA-doped PBI. Based upon these encouraging results, the as-synthesized PAEK-cr-PBI gives a highly practical promise for its application in high-temperature proton exchange membrane fuel cells (HT-PEMFCs).
      PubDate: Fri, 14 Aug 2020 16:35:01 +000
       
  • Evaluation of the Potential Use of Levan Polysaccharide in Paper
           Conservation

    • Abstract: Conservation of paper-based materials, namely, manuscripts, includes repair of tears, gap filling, consolidation, and fixation, which requires the use of adhesives. The adhesive in use for these purposes should be compatible with the chemical and physical properties of paper and should present good aging characteristics. In this study, we conducted a set of experiments with paper samples on which fructan-based biopolymer Halomonas levan (Hlevan) was applied for the first time and compared with glucan-based adhesive starch. Adhesive-applied samples were initially prepared by the application of different historical recipes of sizing and ink. Then, they underwent accelerated thermal aging. Chemical and physical changes of paper samples (crystallinity, pH, and color) were analyzed. Finally, Principal Component Analysis was performed to identify dominating factors affecting sample behavior with applied adhesives. This study demonstrates the aging characteristics of Hlevan on cellulose-based materials. The results showed that there is a color shift from blue to yellow for all samples after aging, but it is more pronounced for some samples with Hlevan. In addition, Hlevan is slightly less acidic than starch in all cases and acted as a plasticizer for a specific kind of sizing material. The methodology of this research is also efficacious in terms of understanding the interaction of paper media with the adhesives and their effects on aging.
      PubDate: Mon, 10 Aug 2020 14:20:02 +000
       
  • 3D In Vitro Human Organ Mimicry Devices for Drug Discovery, Development,
           and Assessment

    • Abstract: The past few decades have shown significant advancement as complex in vitro humanized systems have substituted animal trials and 2D in vitro studies. 3D humanized platforms mimic the organs of interest with their stimulations (physical, electrical, chemical, and mechanical). Organ-on-chip devices, including in vitro modelling of 3D organoids, 3D microfabrication, and 3D bioprinted platforms, play an essential role in drug discovery, testing, and assessment. In this article, a thorough review is provided of the latest advancements in the area of organ-on-chip devices targeting liver, kidney, lung, gut, heart, skin, and brain mimicry devices for drug discovery, development, and/or assessment. The current strategies, fabrication methods, and the specific application of each device, as well as the advantages and disadvantages, are presented for each reported platform. This comprehensive review also provides some insights on the challenges and future perspectives for the further advancement of each organ-on-chip device.
      PubDate: Mon, 10 Aug 2020 13:20:01 +000
       
  • 3-Bromopyridine-Heterogenized Phosphotungstic Acid for Efficient
           Trimerization of Biomass-Derived 5-Hydroxymethylfurfural with
           2-Methylfuran to C21 Fuel Precursor

    • Abstract: The production of long-chain carbon compounds (C9-C21) from biomass derivatives to alternate traditional fossil diesel is sustainable, eco-friendly, and potentially economic for modern industry. In this work, phosphotungstic acid heterogenized by 3-bromopyridine was achieved using a solvothermal method, which was demonstrated to be efficient for trimerization of biomass-derived 5-hydroxymethylfurfural (HMF) with 2-methylfuran (2-MF) to C21 fuel precursor (57.1% yield) under mild reaction conditions. The heterogeneous acidic catalyst could be reused for four consecutive cycles without obvious loss of activity, and different characterization techniques (e.g., XRD (X-ray diffraction), TG (thermogravimetric analysis), SEM (scanning electron microscope), FT-IR (Fourier transform infrared spectroscopy), and BET (Brunauer-Emmet-Teller)) were utilized to investigate the performance of the catalyst. In addition, a plausible reaction pathway was postulated, on the basis of results obtained by NMR (nuclear magnetic resonance) and GC-MS (gas chromatography-mass spectrometer). This strategy provides a facile and efficient approach to prepare a recyclable acidic catalyst for the production of diesel fuel precursor from biomass via controllable polymerization.
      PubDate: Thu, 06 Aug 2020 14:35:03 +000
       
  • A Review of Methods Used to Reduce the Effects of High Temperature
           Associated with Polyamide 12 and Polypropylene Laser Sintering

    • Abstract: The polymer laser sintering (PLS) process is one of the most promising additive manufacturing (AM) technologies for polymeric materials. However, the technique has challenges because the physical, mechanical, and chemical properties of the polymeric powder deteriorate due to the high temperatures prevailing in the build chamber during manufacture. These high temperatures cause agglomeration of powder, which leads to a decrease in the flowability of powder. There is also a related drop in the coalescence of the powder granules during PLS, which results in porosity that undermines the mechanical integrity of printed parts. Moreover, the viscosity of the melt increases due to cross-linking of molecular chains. This, in turn, increases the tensile strength of the printed components at the expense of the percentage elongation at break. Thus, high prolonged processing temperatures decrease the reusability of polymeric materials used in PLS. In this paper, a review of the studies conducted to investigate ways of reducing the effects of high temperature on polymeric powders is presented.
      PubDate: Tue, 04 Aug 2020 07:35:02 +000
       
  • Synthesis of Graphene Oxide-Polystyrene Graft Polymer Based on Reversible
           Addition Fragmentation Chain Transfer and Its Effect on Properties,
           Crystallization, and Rheological Behavior of Poly (Lactic Acid)

    • Abstract: Graphene oxide-polystyrene graft polymer (SGO-PS) was prepared by reversible addition-fragmentation chain transfer radical polymerization method. Orthogonal experiments indicated that the optimum synthesis reaction conditions for SGO-PS were as follows: the millimole ratio of chain transfer agent to initiator was 0.15 : 0.3, and the amount of styrene was 8 mL at 80°C for 12 hours. The products were characterized by Fourier transform infrared spectroscopy and thermal weightlessness analysis, and the highest grafting rate of SGO-PS was 62.46%. Then, PLA/SGO-PS nanocomposites were prepared using SGO-PS as fillers by melt intercalation method, and its crystallinity, mechanical properties, and thermal stability were significantly improved. Compared with pure PLA, the crystallinity of PLA/SGO-PS (0.3 wt%) nanocomposites was increased by 5 times. Multiple melting behavior tests showed that the introduction of SGO-PS caused the PLA molecular chain to be discharged into the unit cell in time, and the melting temperature shifted to a higher temperature, which ultimately made the grain structure of PLA composites more complete and stable than pure PLA. The rheological performance test showed that the uniform dispersion of SGO-PS in the PLA matrix inhibited the free movement of the PLA molecular chain and caused higher flow resistance, resulting in an increase in the complex viscosity, storage modulus, and loss modulus of PLA/SGO-PS.
      PubDate: Wed, 29 Jul 2020 14:50:02 +000
       
  • Separation of CO2 from Small Gas Molecules Using Deca-Dodecasil 3
           Rhombohedral (DDR3) Membrane Synthesized via Ultrasonically Assisted
           Hydrothermal Growth Method

    • Abstract: Deca-dodecasil 3 rhombohedral (DDR3) membrane has received much attention in CO2 separation from small gas molecules because of its molecular sieving property and stable characteristics. Therefore, the present work is focusing on the utilization of previously fabricated membrane (synthesized in 3 days as reported in our previous work) to study the effect of hydrocarbons and its durability at the previously optimized conditions. Subsequently, gas permeation study was conducted on the DDR3 membrane in CO2 separation from small gas molecules and it was found that the permeance of H2, CO2, N2, and CH4 decreased in the order of H2 > CO2 > N2 > CH4, according to the increase in kinetic diameter of these gas molecules. Besides, it was observed that the ideal selectivities of the gas pairs decreased in the sequence of CO2/CH4 > CO2/N2 > H2/CO2. On the other hand, it was found that the presence of hydrocarbon impurities in the gas mixture containing CO2 and CH4 has directly affected the performance of DDR3 membrane and contributed to the losses of CO2 permeability, CH4 permeability, and CO2/CH4 selectivity of 39.1%, 14.8%, and 4.2%, respectively. Consequently, from the stability test, the performance of DDR3 membrane remained stable for 96 h, even after the separation testing using CO2 and CH4 gas mixture containing hydrocarbon impurities.
      PubDate: Mon, 20 Jul 2020 15:35:03 +000
       
  • A Novel Gel Polymer Electrolyte by Thiol-Ene Click Reaction Derived from
           CO2-Based Polycarbonate for Lithium-Ion Batteries

    • Abstract: Here, we describe the synthesis of a CO2-based polycarbonate with pendent alkene groups and its functionalization by grafting methoxypolyethylene glycol in view of its application possibility in gel polymer electrolyte lithium-ion batteries. The gel polymer electrolyte is prepared by an in-situ thiol-ene click reaction between polycarbonate with pendent alkene groups and thiolated methoxypolyethylene glycol in liquid lithium hexafluorophosphate electrolyte and exhibits conductivity as remarkably high as at ambient temperature. To the best of our knowledge, this gel polymer electrolyte possesses the highest conductivity in all relevant literatures. A free-standing composite gel polymer electrolyte membrane is obtained by incorporating the gel polymer electrolyte with electrospun polyvinylidene fluoride as a skeleton. The as-prepared composite membrane is used to assemble a prototype lithium iron phosphate cell and evaluated accordingly. The battery delivers a good reversible charge-discharge capacity close to 140 mAh g-1 at 1 C rate and 25°C with only 0.022% per cycle decay after 200 cycles. This work provides an interesting molecular design for polycarbonate application in gel electrolyte lithium-ion batteries.
      PubDate: Fri, 17 Jul 2020 06:20:01 +000
       
 
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