Chitosan‐polyvinyl alcohol‐sulfonated polyethersulfone mixed‐matrix membranes as methanol‐barrier electrolytes for DMFCs

Abstract

Chitosan (CS)-polyvinyl alcohol (PVA) cross-linked with sulfosuccinic acid (SSA) and modified with sulfonated polyethersulfone (SPES) mixed-matrix membranes are reported for their application in direct methanol fuel cells (DMFCs). Polyethersulfone (PES) is sulfonated by chlorosulfonic acid and factors affecting the sulfonation reaction, such as time and temperature, are studied. The ion-exchange capacity, degree of sulfonation, sorption, and proton conductivity for the mixed-matrix membranes are investigated. The mixed-matrix membranes are also characterised for their mechanical and thermal properties. The methanol-crossover flux across the mixed-matrix membranes is studied by measuring the mass balance of methanol using the density meter. The methanol cross-over for these membranes is found to be about 33% lower in relation to Nafion-117 membrane. The DMFC employing CS-PVA-SPES mixed-matrix membrane with an optimum content of 25 wt % SPES delivers a peak power-density of 5.5 mW cm À2 at a load currentdensity of 25 mA cm À2 while operating at 70

Natural and synthetic solid polymer hybrid dual network membranes as electrolytes for direct methanol fuel cells

“…4d-g. The morphology is in accordance with our earlier reports on similar kinds of blend membranes [62].…”

Preparation and Characterization of an Eco-Friendly Polymer Electrolyte Membrane (PEM) Based in a Blend of Sulphonated Poly(Vinyl Alcohol)/ Chitosan Mechanically Stabilised by Nylon 6,6

“…These membranes have shown proton conductivity similar to some results found in the literature for membranes using PVAL or CS. 4,5,11,18 Proton conductivity results are in agreement with IEC values, both increased with SSA quantity.…”

“…The main degradation stages occur due to dehydration, degradation and decomposition of polymeric backbone and blend. 4,6,24 Thermal degradation starts at 140 °C for lower CS content membranes (Figure 3 (A)). DTG (Figure 3 (A)) shows that SSA crosslink interferes directly with membrane degradation process.…”

“…Therefore, natural polymer chitosan (CS) and synthetic polymer poly(vinyl alcohol) (PVAL) have drawn considerable attention. [3][4][5][6] CS is the second most abundant natural biopolymer obtained by chitin alkaline deacetylation. Due to its low cost production, natural abundance and eco-compatibility, CS is the preferred bio-material membrane for ultra-filtration, reverse-osmosis and pervaporation.…”

Sulfonated fullerene in SPEEK matrix and its impact on the membrane electrolyte properties in direct methanol fuel cells

“…Few of the important ones namely sulfonated polyimide, sulfonated polyether ether ketone and sulfonated polyether sulfone [8][9][10][11][12][13][14]; synthetic polymers like polyvinyl alcohol [15] and bio-polymers like chitosan and sodium alginate [16][17][18] are used to develop membrane electrolytes for DMFCs. Literature reviews are available which explains in detail the properties of sulfonated polyether ether ketone (SPEEK) polymer for preparation of membrane electrolyte as a potential replacement for Nafion in DMFC due to its good chemical, thermal and mechanical stabilities in addition to its low cost.…”