Enhancement in hydrolytic stability and proton conductivity of optimised chitosan/sulfonated poly(vinyl alcohol) composite membrane with inorganic fillers

Electrolyte nanocomposite membranes for proton exchange membrane fuel cells and direct methanol fuel cells were prepared by carrying out a sulfonation of poly(vinyl alcohol) with sulfosuccinic acid and adding a type of organically modified montmorillonite (layered silicate nanoclay) commercially known as Cloisite 93A. The effects of the different concentrations (0, 2, 4, 6, 8 wt. %) of the organoclay in the membranes on water uptake, ion exchange capacity (IEC), proton conductivity, and methanol permeability were measured, respectively, via gravimetry, titration, impedance analysis, and gas chromatography techniques. The IEC values remained constant for all concentrations. Water uptakes and proton conductivities of the nanocomposite membranes changed with the clay content in a nonlinear fashion. While all the nanocomposite membranes had lower methanol permeability than Nafion115, the 6% concentration of Cloisite 93A in sulfonated poly(vinyl alcohol) membrane displayed the greatest proton conductivity to methanol permeability ratio.

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Hybrid Composite Membrane of Phosphorylated Chitosan/Poly (Vinyl Alcohol)/Silica as a Proton Exchange Membrane

Membranes ◽

10.3390/membranes11090675 ◽

2021 ◽

Vol 11 (9) ◽

pp. 675

Author(s):

Nur Adiera Hanna Rosli ◽

Kee Shyuan Loh ◽

Wai Yin Wong ◽

Tian Khoon Lee ◽

Azizan Ahmad

Keyword(s):

Proton Conductivity ◽

Composite Membrane ◽

Vinyl Alcohol ◽

Proton Exchange Membrane ◽

Mechanical Stability ◽

Composite Membranes ◽

Proton Exchange ◽

Inorganic Filler ◽

Poly Vinyl Alcohol ◽

Filler Concentration

Chitosan is one of the natural biopolymers that has been studied as an alternative material to replace Nafion membranes as proton change membranes. Nevertheless, unmodified chitosan membranes have limitations including low proton conductivity and mechanical stability. The aim of this work is to study the effect of modifying chitosan through polymer blending with different compositions and the addition of inorganic filler on the microstructure and physical properties of N-methylene phosphonic chitosan/poly (vinyl alcohol) (NMPC/PVA) composite membranes. In this work, the NMPC biopolymer and PVA polymer are used as host polymers to produce NMPC/PVA composite membranes with different compositions (30–70% NMPC content). Increasing NMPC content in the membranes increases their proton conductivity, and as NMPC/PVA-50 composite membrane demonstrates the highest conductivity (8.76 × 10−5 S cm−1 at room temperature), it is chosen to be the base membrane for modification by adding hygroscopic silicon dioxide (SiO2) filler into its membrane matrix. The loading of SiO2 filler is varied (0.5–10 wt.%) to study the influence of filler concentration on temperature-dependent proton conductivity of membranes. NMPC/PVA-SiO2 (4 wt.%) exhibits the highest proton conductivity of 5.08 × 10−4 S cm−1 at 100 °C. In conclusion, the study shows that chitosan can be modified to produce proton exchange membranes that demonstrate enhanced properties and performance with the addition of PVA and SiO2.

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Easy, operable ionic polymer metal composite actuator based on a platinum-coated sulfonated poly(vinyl alcohol)-polyaniline composite membrane

Journal of Applied Polymer Science ◽

10.1002/app.43787 ◽

2016 ◽

Vol 133 (33) ◽

Cited By ~ 9

Author(s):

Ajahar Khan ◽

Inamuddin ◽

Ravi Kant Jain

Keyword(s):

Composite Membrane ◽

Vinyl Alcohol ◽

Poly Vinyl Alcohol ◽

Metal Composite ◽

Ionic Polymer Metal Composite ◽

Ionic Polymer ◽

Composite Actuator ◽

Polymer Metal ◽

Sulfonated Poly

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Crosslinked Sulfonated Poly(vinyl alcohol)/Graphene Oxide Electrospun Nanofibers as Polyelectrolytes

Nanomaterials ◽

10.3390/nano9030397 ◽

2019 ◽

Vol 9 (3) ◽

pp. 397 ◽

Cited By ~ 9

Author(s):

Oscar Gil-Castell ◽

Diana Galindo-Alfaro ◽

Soraya Sánchez-Ballester ◽

Roberto Teruel-Juanes ◽

José Badia ◽

...

Keyword(s):

Graphene Oxide ◽

Proton Conductivity ◽

Vinyl Alcohol ◽

Electrospun Nanofibers ◽

Poly Vinyl Alcohol ◽

Polyelectrolyte Membranes ◽

Sulfosuccinic Acid ◽

Size And Morphology ◽

Sulfonated Poly

Taking advantage of the high functionalization capacity of poly(vinyl alcohol) (PVA), bead-free homogeneous nanofibrous mats were produced. The addition of functional groups by means of grafting strategies such as the sulfonation and the addition of nanoparticles such as graphene oxide (GO) were considered to bring new features to PVA. Two series of sulfonated and nonsulfonated composite nanofibers, with different compositions of GO, were prepared by electrospinning. The use of sulfosuccinic acid (SSA) allowed crosslinked and functionalized mats with controlled size and morphology to be obtained. The functionalization of the main chain of the PVA and the determination of the optimum composition of GO were analyzed in terms of the nanofibrous morphology, the chemical structure, the thermal properties, and conductivity. The crosslinking and the sulfonation treatment decreased the average fiber diameter of the nanofibers, which were electrical insulators regardless of the composition. The addition of small amounts of GO contributed to the retention of humidity, which significantly increased the proton conductivity. Although the single sulfonation of the polymer matrix produced a decrease in the proton conductivity, the combination of the sulfonation, the crosslinking, and the addition of GO enhanced the proton conductivity. The proposed nanofibers can be considered as good candidates for being exploited as valuable components for ionic polyelectrolyte membranes.

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Fabrication and Characterization of Low-Cost Poly(Vinyl Alcohol) Composite Membrane for Low Temperature Fuel Cell Application

Journal of Applied Membrane Science & Technology ◽

10.11113/amst.v22n1.128 ◽

2018 ◽

Vol 22 (1) ◽

Author(s):

Ruhilin Nasser ◽

Siti Khadijah Hubadillah ◽

Mohd Hafiz Dzarfan Othman ◽

Arif Akmal Mohamed Hassan

Keyword(s):

Contact Angle ◽

Fuel Cell ◽

Proton Conductivity ◽

Water Uptake ◽

Composite Membrane ◽

Vinyl Alcohol ◽

Proton Exchange ◽

High Price ◽

Poly Vinyl Alcohol ◽

Weight Percentage

The urge to find alternative sources of energy is crucial as the source of fossil fuel shows a high number of depletion over the year. Compared to other alternatives sources, fuel cell is high at rank as it generates no harmful gases to the surrounding and high in efficiency. The performance of this fuel cell is affected by several factors and one of it is the permeability of proton exchange membrane (PEM). Nafion® is known to be used as the PEM in fuel cells, however due to its high price, polyvinyl alcohol membrane was selected in this study to substitute the Nafion® as it was low in price and excellent in chemical and mechanical strength. Poly (vinyl alcohol) composite membrane was prepared and crosslinked with sulfosuccinic acid (SSA). To further increase the proton conductivity of the membrane, graphene oxide (GO) with 1, 2 and 3 weight percentage was incorporated into the polymer membrane. All the membranes were characterized by using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), water uptake measurement, contact angle, ion exchange capacity and proton conductivity respectively. Synthesized membranes show low water uptake and contact angle as GO loading was increased. IEC value and water swelling were found to be increased with increasing of GO loading. The proton conductivity of the membrane increases as more GO was incorporated into PVA-SSA and achieved its highest conductivity at 0.020746 S cm-1 with 2 wt. % of GO incorporation.

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