Hybrrid Pronton Exchange Membranes For Direct Ethanol Fuel Cells

The last 15 years have witnessed a rising interest in direct liquid fuel cells based on the polymer electrolyte membrane (PEM) technology for mobile and portable applications. But membrane swelling and fuel crossover can significantly undermine the fuel cell performance particularly for DEFCs which were beset with poor electrode kinetics. For this reason, synthesis the high proton conductivity and small fuel crossover will be needed. In this paper, a series of hybrid proton-conducting membranes with an interpenetrating polymer network (IPN) structure was designed with the direct ethanol fuel cell (DEFC) application in mind. Four membranes were prepared with different PVA-poly(AMPS-co-HEMA)/silic/α-zirconium phosphate composition. In these membranes, glutaraldehyde crosslinked poly (vinyl alcohol) (PVA) were interpenetrated with the copolymer of 2-acrylamido-2-methyl-propanesulphonic acid (AMPS) and 2-hydroxyethyl methacrylate (HEMA) crosslinked poly (ethylene glycol) dimethacrylate (PEGDMA). Silica from the in situ sol–gel hydrolysis of tetraethyl orthosilicate and crystallineα-ZrP were prepared using precipitation method was uniformly dispersed in the polymer matrix. Finally, the composite membranes were prepared using Tape-casting method on the Organic glass sheet.The properties of the composite membranes were investigated by scanning electron microscopy (SEM), x-ray diffraction (XRD), thermogravimetric analyser (TGA), ion exchange capacity, water and alcohol uptake, FTIR and Mechanical properties.The hybrid membranes with silica and zirconium phosphate not only have better swelling but also ion exchange capacity than pure organic membrane. The swelling characteristics of the membranes are all relatable to the unique swelling characteristics of PVA (no swelling in ethanol, partial swelling in methanol and extensive swelling in water) and swelling suppression properties of silica particles. The IEC values of the hybrid membranes ranged from 0.84 to1.49mequiv.g-1, IEC increases expectedly with the increase in the zirconium phosphate content. The interaction betweenα-ZrP and copolymer possibly through hydrogen bonding, while the interactions involve silanol groups from silica and -OH and from the polymer, crosslink by condensation reaction combine with covalent bonding between them. The composite membranes with silica and zirconium phosphate have better water retention and thermal stability than pure organic membrane as well as mechanical properties. Comparing the characteristics of the series of composite membranes, the best overall character of membrane is the membrane with 6% silica and 6% zirconium phosphate.