Sulfonated Poly(styrene-co-maleic anhydride)−Poly(ethylene glycol)−Silica Nanocomposite Polyelectrolyte Membranes for Fuel Cell Applications

Abstract

A method for the preparation of highly conductive and stable organic-inorganic nanocomposite polyelectrolyte membranes with controlled spacing between inorganic segment and covalently bound sulfonic acid functional groups has been established. These polyelectrolyte membranes were prepared by condensation polymerization of the silica precursor (tetraethylorthosilicate) in dimethylacetamide in the presence of poly(ethylene glycol) (PEG) of desired molecular weight, and sulfonated poly(styrene-co-maleic anhydride) was attached to the polymeric backbone by hydrogen bonding. Molecular weight of PEG has been systematically changed to control the nanostructure of the developed polymer matrix for studying the effects of molecular structure on the thermal as well as conductive properties. These polyelectrolyte membranes were extensively characterized by studying their thermo-gravimetric analysis (TGA), ion-exchange capacity (IEC), water content, conductivity, methanol permeability, and current-voltage polarization curves under direct methanol fuel cell (DMFC) operating conditions as a function of silica content and molecular weight of PEG used for membrane preparation. Moreover, from these studies and estimation of selectivity parameter among all synthesized membranes, 30% silica content and 400 Da molecular weight of PEG resulted in the best nanocomposite polyelectrolyte membranes, which exhibited performance comparable to that of the Nafion 117 membrane for DMFC applications.

Nafion® nanocomposite membranes: Effect of fluorosurfactants on hydrophobic silica nanoparticle dispersion and direct methanol fuel cell performance

“…Methanol permeability can be lowered by tuning the hydrophilic channel size in hydrophilic-hydrophobic block copolymer membranes or by surface modification of polymer electrolyte membranes [13][14][15]. Organic-inorganic nanocomposite membranes with nanometer size fillers have been explored intensively and remain one of the most interesting avenues for the preparation of electrolytes for application in fuel cells [9,11,[16][17][18][19][20][21]. 0378 In a previous studies [21][22][23], various hydrocarbon-based nonionic surfactants consisting of hydrophobic and hydrophilic segments (e.g., PEO x -PPO y -PEO x triblock copolymers) were used to disperse nanometer-size fillers (such as silica) evenly in hydrocarbonbased polymer electrolyte membranes.…”

Comparative studies on performance of radiation-induced and thermal cross-linked ion-exchange membrane for water electrolysis

“…Poly(ether ether ketone) (PEEK), poly(ether sulfone) (PES), polyimides, polybenzimidazoles and organic-inorganic composites cation-exchange membranes were reported in the literature (Hickner et al, 2004;Tripathi and Shahi, 2008;Saxena et al, 2007aSaxena et al, , 2007b. Aromatic based PEMs were prepared either by sulfonation of super-engineering plastics or copolymerization of aromatic monomers containing sulfonic acid groups (Chen et al, 2007).…”

Bifunctionalized organic–inorganic charged nanocomposite membrane for pervaporation dehydration of ethanol

“…For controlling membrane swelling, reports are available including introduction of cross-linked structure to the membrane, blending of chitosan with other polymers, and developing organic-inorganic hybrid membranes [4][5][6][7][8][9][10][11][12][13][14][15][16]. Recently, sol-gel based organic-inorganic hybrid materials are reported to be the next generation of membrane forming material with high stabilities and reduced swelling properties because of controlled cross-linking and bond formation between organic and inorganic segments [4,6,[17][18][19][20][21][22][23][24][25].…”