Molecular Crystals and Liquid Crystals, Vol.407, 411-419, 2003
Nanocomposite polymer membrane based on cation exchange polymer and nano-dispersed clay sheets
Nafion/organo-clay nanocomposite membranes were prepared by solution intercalation technique in order to reduce methanol permeability while maintaining essential proton conductivity. Featureless XRD patterns of nanocomposite indicated that organically treated clay particles were completely disordered and exfoliated in continuous Nafion matrix at clay loading less than 10 wt%. TEMicrographs also revealed that nanolayers of clay are well delaminated in Nafion matrix. In addition, thermal degradation and glass transition temperature were slightly shifted to higher temperature due to strong adhesion of Nafion chains on organo-clays. It was observed that methanol permeability of Nafion 117 (similar to180 mum) was ca. 2.3 x 10(-6) cm(2)/S while that of Nafion/organo-clay nanocomposite membrane (similar to50 mum) decreased down to 1.6 x 10(-7) cm(2)/S only by 1 wt% clay loading, without apparent conductivity loss. This improvement might result from greater affinity of nanocomposite membrane for water over methanol.