Development of sulfonated poly(ether ether ketone)/zirconium titanium phosphate composite membranes for direct methanol fuel cell

Abstract

The present work addresses the development of economic membrane material with superior proton conductivity and less methanol crossover. Sulfonated poly(ether ether ketone) (SPEEK) composite membranes with various loading of zirconium titanium phosphate (ZTP) have been prepared by solution casting method. The structural and thermal properties of the ZTP powder are evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), BET surface area measurement, Fourier transform infrared spectroscopy (FTIR), and Thermo gravimetric analysis (TGA). The produced composite membranes are also characterized by evaluating the ion exchange capacity (IEC), water uptake, methanol uptake, thermal stability, proton conductivity, and methanol crossover as a function of ZTP loading. The proton conductivity of composite membrane is fourfold higher than that of the pure SPEEK membrane and also increases with an increase in the ZTP loading. The methanol permeability of the composite membrane containing 15% ZTP decreases by 264% (and 21%) when compared with pure SPEEK (and commercial Nafion 117 membrane). Over all, the selectivity of the SPEEK/ZTP composite membrane is found to be 15-and 3-fold higher than the pure SPEEK membrane and Nafion 117 membrane, respectively. Hence, the synthesized SPEEK composite membrane could be utilized as low cost alternative for the high cost commercial membranes. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124: E45-E56, 2012

Effect of thermal crosslinking on the properties of sulfonated poly(phenylene sulfone)s as proton conductive membranes

“…Recent research has been devoted to the development of fluorine‐free aromatic‐type proton exchange membranes as alternatives to state‐of‐the‐art perfluorinated ionomer membranes such as Nafion, since perfluorinated ionomer membranes suffer from high production cost, loss of conductivity at relatively high temperature (>100 °C) and low humidity, hindering their practical applications . A wide variety of aromatic polymers, such as poly(arylene ether sulfone)s, poly(ether ether ketone)s, polyphenylenes, and polyimides have been studied as basic materials for PEMs. Among them, poly(phenylene sulfone)s (PPSU) with excellent thermal stability, low cost, and good membrane forming capability have been applied widely .…”

New approaches towards novel composite and multilayer membranes for intermediate temperature-polymer electrolyte fuel cells and direct methanol fuel cells

“…Sangeetha Rani, et al [60] prepared a composite membranes with zirconium titanium phosphate (ZTP) loaded in a SPEEK matrix for DMFC. The authors investigated the effect of [26] ZTP loading (5, 10 and 15 wt.% of ZTP loading) and noticed that the ion exchange capacity (IEC) increased with increase in loading up to 5 wt.% of ZTP, beyond this loading the IEC was reported to decrease and the loss in IEC was attributed to the strong interactions between the sulphonic acid groups of the polymer and ZTP.…”

Effect of phosphotungstic acid blending on properties of sulfonated poly(ether ether ketone)–poly(ethylene glycol) crosslinked membranes

“…The combination of an organic material's properties (conductivity, flexibility, processability) and an inorganic material's properties (chemical and thermal stability, decreased fuel permeability, increased water retention) led to improved results. Various materials that have been used extensively for composite membrane fabrication include MO 2 inorganic oxides (M = Ti, Zr, Si), clays, zeolites, and heteropoly acids . Heteropoly acids (HPAs) are one of the good inorganic modifiers because of their unique properties like high conductivity, thermal stability, high selectivity, and noncorrosive nature (with a few exceptions) .…”

“…Various materials that have been used extensively for composite membrane fabrication include MO 2 inorganic oxides (M 5 Ti, Zr, Si), clays, zeolites, and heteropoly acids. [23][24][25][26][27][28][29] Heteropoly acids (HPAs) are one of the good inorganic modifiers because of their unique properties like high conductivity, thermal stability, high selectivity, and noncorrosive nature (with a few exceptions). 30 Solid HPAs have a discrete ionic structure, comprising fairly mobile heteropoly anions and countercations (H 1 , H 3 O 1 , H 5 O 1 2 , and so on), unlike the network structure of zeolites and metal oxides.…”