Membranes based on polyimide–polyaniline nanocomposites for pervaporation of organic mixtures

Polyimide-polyaniline nanocomposites were obtained by mixing poly{(4,4 0 -bis(4 00 -N-phenoxy)diphenylsul- fone)imide-1,3-bis(3,4-dicarboxyphenoxy)benzene} (PI) and polyaniline (PANI) solutions in N-methylpyrrolidone. These solutions were used for the preparation of homo- geneous and composite membranes. Uniform distribution of PANI particles in the membranes, resulted from inter- actions between macromolecules, was confirmed by transmission electron microscopy. Membranes based on PI and PI-PANI were tested in pervaporation of binary organic mixtures: methanol/toluene and methanol/cyclo- hexane and showed a remarkable selectivity with respect to methanol. In both pervaporation processes, selectivity was improved in PANI-containing membranes. Interac- tions between membrane polymers and liquid penetrants (methanol, toluene, and cyclohexane) were studied by measurements of surface tension, sorption, and pervapo- ration parameters. V C 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 2175-2182, 2010