scholarly journals Preparation and Identification of Optimal Synthesis Conditions for a Novel Alkaline Anion-Exchange Membrane

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 913 ◽  
Author(s):  
Aitor Marcos-Madrazo ◽  
Clara Casado-Coterillo ◽  
Leticia García-Cruz ◽  
Jesús Iniesta ◽  
Laura Simonelli ◽  
...  
Keyword(s):  
Anion Exchange ◽  
Oxidation State ◽  
Water Vapor Permeability ◽  
Filler Loading ◽  
Poly Vinyl Alcohol ◽  
Vapor Permeability ◽  
Mechanical Resistance ◽  
Anion Exchange Membranes ◽  
Copper Oxidation ◽  
Synthesis Conditions

The physicochemical and mechanical properties of new alkaline anion-exchange membranes (AAEMs) based on chitosan (CS) and poly(vinyl alcohol) (PVA) polymers doped with unsupported copper nanoparticles (NPs) and copper exchanged over different porous materials were investigated regarding ion-exchange capacity (IEC), OH− conductivity, water uptake (WU), water vapor permeability (WVP), and thermal and mechanical resistance. The influence of the type of filler included in different morphologies and filler loading has been explored using copper exchanged materials such as the layered porous titanosilicate AM-4, layered stannosilicate UZAR-S3, and zeolites Y, MOR, and BEA. Compared to commercially available anion-exchange membranes, the best performing membranes in terms of WU, IEC, OH− conductivity and WVP in this study were those containing 10 wt % of Cu-AM-4 and Cu-UZAR-S3, although 10 wt % Cu-MOR provided better mechanical strength at close values of WVP and anion conductivity. It was also observed that when Cu was exchanged in a porous silicate matrix, its oxidation state was lower than when embedded as unsupported metal NPs. In addition, the statistical analysis of variance determined that the electrochemical properties of the membranes were noticeably affected by both the type and filler loading, and influenced also by the copper oxidation state and content in the membrane, but their hydrophilic properties were more affected by the polymers. The largest significant effects were noticed on the water sorption and transport properties, which gives scope for the design of AAEMs for electrochemical and water treatment applications.

Development of quaternarized poly(vinyl alcohol) anion-exchange membranes for applications in electrodialysis

2017 ◽  
Vol 134 (31) ◽  
pp. 44946 ◽  
Author(s):  
Franciélli Müller ◽  
Rafaela Andretta ◽  
Lorenzo de Oliveira Meneguzzi ◽  
Carlos Arthur Ferreira
Keyword(s):  
Anion Exchange ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Anion Exchange Membranes

scholarly journals Mussel-Inspired Approach to Constructing Dual Network Coated Layered Clay for Enhanced Barrier and Antibacterial Properties of Poly(vinyl alcohol) Nanocomposites

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2093
Author(s):  
Long Mao ◽  
Jianda Xie ◽  
Huiqing Wu ◽  
Yuejun Liu
Keyword(s):  
Vinyl Alcohol ◽  
Antibacterial Properties ◽  
Water Vapor Permeability ◽  
Poly Vinyl Alcohol ◽  
Vapor Permeability ◽  
One Pot ◽  
Solution Casting Method ◽  
Uv Transmittance ◽  
Layered Clay ◽  
Double Hydroxides

Inspired by complexation and mussel adhesion of catechol groups in tannic acid (TA), organophilic layered double hydroxides (LDHs@TA-Ti) were synthesized by forming a one-pot assembled TA-titanium (Ti) dual network coating on the surface of layered clay for the first time. LDHs@TA-Ti/poly(vinyl alcohol) (PVA) nanocomposites were prepared by the solution casting method. The results show that TA-Ti(IV) and TiO2 coordination compounds are simultaneously formed due to hydrolysis of titanium tetrachloride and complexation of TA in aqueous solution. Upon TA-Ti coatings onto the surface of LDHs, the antibacterial rate of LDHs@TA-Ti is up to 99.98%. Corresponding LDHs@TA-Ti/PVA nanocomposites also show outstanding antibacterial properties. Compared with pure PVA, LDHs@TA-Ti/PVA nanocomposites show a 40.9% increase in tensile strength, a 17.5% increase in elongation at break, a 35.9% decrease in oxygen permeability and a 26.0% decrease in water vapor permeability when adding 1 wt % LDHs@TA-Ti. UV transmittance (at 300 nm) of LDHs@TA-Ti/PVA nanocomposites decrease by 99.4% when the content of LDHs@TA-Ti reaches 3 wt %. These results indicate that PVA matrix incorporated with LDHs@TA-Ti could be used as a potential active packaging material to extend the shelf life of food products.

scholarly journals A Functional Wound Dressing as a Potential Treatment for Cutaneous Leishmaniasis

Pharmaceutics ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 200 ◽  
Author(s):  
Francisco Alexandrino-Junior ◽  
Kattya Gyselle de Holanda e Silva ◽  
Marjorie Caroline Liberato Cavalcanti Freire ◽  
Viviane de Oliveira Freitas Lione ◽  
Elisama Azevedo Cardoso ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Topical Treatment ◽  
Healing Process ◽  
Water Vapor Permeability ◽  
Vero Cells ◽  
Poly Vinyl Alcohol ◽  
Vapor Permeability ◽  
Secondary Infections ◽  
Leishmania Spp

Cutaneous leishmaniasis (CL) is a parasitic disease characterized by progressive skin sores. Currently, treatments for CL are limited to parenteral administration of the drug, which presents severe adverse effects and low cure rates. Therefore, this study aimed to develop poly(vinyl-alcohol) (PVA) hydrogels containing Amphotericin B (AmB) intended for topical treatment of CL. Hydrogels were evaluated in vitro for their potential to eliminate promastigote forms of Leishmania spp., to prevent secondary infections, to maintain appropriate healing conditions, and to offer suitable biocompatibility. AmB was incorporated into the system in its non-crystalline state, allowing it to swell more and faster than the system without the drug. Furthermore, the AmB release profile showed a continuous and controlled behavior following Higuchi´s kinetic model. AmB-loaded-PVA-hydrogels (PVA–AmB) also showed efficient antifungal and leishmanicidal activity, no cytotoxic potential for VERO cells, microbial impermeability and water vapor permeability compatible with the healthy skin’s physiological needs. Indeed, these results revealed the potential of PVA–AmB to prevent secondary infections and to maintain a favorable environment for the healing process. Hence, these results suggest that PVA–AmB could be a suitable and efficient new therapeutic approach for the topical treatment of CL.

scholarly journals Preparation and Characterization of PVA/PDDA/Nano-Zirconia Composite Anion Exchange Membranes for Fuel Cells

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1399 ◽  
Author(s):  
Asep Muhamad Samsudin ◽  
Viktor Hacker
Keyword(s):  
Mechanical Properties ◽  
Fuel Cells ◽  
Anion Exchange ◽  
Testing Machine ◽  
Conductivity Measurement ◽  
Poly Vinyl Alcohol ◽  
Anion Exchange Membranes ◽  
Potential Candidate ◽  
Casting Technique ◽  
Chemical Structures

Anion exchange membranes (AEMs) contribute significantly to enhance the performance and efficiency of alkaline polymer electrolyte fuel cells (APEFCs). A sequence of composite anion exchange membranes (AEMs) consisting of poly(vinyl alcohol) (PVA), poly(diallyldimethylammonium chloride) (PDDA), and nano-zirconia (NZ) has been prepared by a solution casting technique. The effect of zirconia mass ratio on attribute and performance of composite AEMs was investigated. The chemical structures, morphology, thermal, and mechanical properties of AEMs were characterized by FTIR, SEM, thermogravimetric analysis, and universal testing machine, respectively. The performance of composite AEMs was verified using water uptake, swelling degree, ion-exchange capacity, and OH− conductivity measurement. The nano-zirconia was homogeneously dispersed in the PVA/PDDA AEMs matrix. The mechanical properties of the composite AEMs were considerably enhanced with the addition of NZ. Through the introduction of 1.5 wt.% NZ, PVA/PDDA/NZ composite AEMs acquired the highest hydroxide conductivity of 31.57 mS·cm−1 at ambient condition. This study demonstrates that the PVA/PDDA/NZ AEMs are a potential candidate for APEFCs application.

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