Heteropolyacids composite membranes

V. Ramani, H.R. Kunz, and J.M. Fenton, Stabilized Heteropolyacid/Nafion Composite Membranes for Elevated Temperature/Low Relative Humidity PEFC Operation, Electrochimica Acta, 50, 1181-87 (2005). 

Kim, Y. S., Wang, R, Hickner, M., Zawodzinski, T. A. and McGrath, J. E. 2003. Fabrication and characterization of heteropolyacid (H3PWJ2O4Q)/directly polymerized sulfonated polyjarylene ether sulfone) copolymer composite membranes for higher temperature fuel cell applications. Journal of Membrane Science 2112 263-282. 

Ramani, V. Kunz, H. R. Fenton, J. M., Stabilized heteropolyacid/Nafion [trademark] composite membranes for elevated temperature/low relative humidity PEFC operation. Electrochimica Acta 2005, 50, (5), 1181-1187. 

The introduction of nitrile groups into proton conductive sulfonated thermoplastics decreases their moisture absorption. Nitriles promote the adhesion of the polymers to heteropolyacids (HPA)s in composite membranes or to electrodes. In addition, the dimensional stability of the membrane is... 

S. Zaidi, S. Mikhailenko, G. Robertson, M. Guiver, S. Kaliaguine, Proton conducting composite membranes from polyether ether ketone and heteropolyacids for fuel-cell applications. Journal of Membrane Science 173 (2000) 17-34. 

The composite membranes exhibit a low heteropolyacid extraction after treatment with water at 60 °C for 24 h. The proton conductivity of the membranes increases with increasing content of silicotungstic acid. 

Wang, Z., Ni, H., Zhao, C., Li, X., Fue, T. and Na, H. 2006. Investigation of sulfonated poly (ether ether ketone sulfone)/heteropolyacid composite membranes for high temperature fuel cell applications. 44- 1967-1978. 

Zaidi, S.M.1. and Ahmad, M.l. 2006. Novel SPEEK/heteropolyacids loaded MCM-41 composite membranes for fuel cell applications. 279 548-557. 

Xu C, Wu X, Wang X et al (2011) Composite membranes of polybenzimidazole and caesium-salts-of-heteropolyacids for intermediate temperature fuel cells. J Mater Chem 21 6014—6019... 

This chapter is devoted to PBI composite membranes involving a polymer matrix, in this case, the PBI, and another compound in the form of filler (solid oxides, solid acids, heteropolyacids and derived heteropolysalts, pyrophosphates, ionic liquids and even carbonaceous materials). A synergic effect between the two elements always appears crucial in order to improve the membrane characteristics. As in die case of Nation membranes, the motivations for fabricating composite PBl-based membranes fall into the following classification ... 

Lee JW, Khan SB, Akhtar K et al (2012) Fabrication of composite membrane based on silicotungstic heteropolyacid doped polybenzimidazole for high temperature PEMFC. Int J Electrochem Sci... 

New organic-inorganic composite membranes based on sulfonated polyether-ketone (SPEK) and SPEEK were synthesized with SiO, TiO, and ZrO. The modification of SPEK and SPEEK with ZrO reduced the methanol flux by 60-fold. On the other hand, there was a big compromise on conductivity, which was reduced by 13-fold, while modification of PEK and SPEEK with silane (SiO ) led to a 40-fold decrease of water permeability without a large decrease of protonic conductivity [35]. With some encouraging results of the modification of PEK with SiO, TiOj, and ZrO, modification of PEK with heteropolyacid further yielded some notable results. Actually the composite membranes were prepared using an organic matrix... 

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