Bi-functionalized copolymer-sulphonated SiO2 embedded with aprotic ionic liquid based anhydrous proton conducting membrane for high temperature application

We prepared highly charged bi-functionalized copolymer (BFC) and sulphonated mesoporous silica embedded with aprotic ionic liquid (IL) (1-ethyl-3-methylimidazolium ethyl sulfate) based anhydrous conducting cross-linked polymer electrolyte membrane (REM) by sot-get. Composite PEMs with 0-10 wt% sulphonated silica and 20 wt% IL content (BFC/Si-x/IL) were characterized by their morphology, stability, IEC. water retention ability and temperature dependent anhydrous conductivity. Conductivity of pristine BFC membrane (1.57 mS cm(-1)) was increased with incorporation of sulphonatecl-SiO2 (10 wt%) in the membrane matrix (BFC/Si-10) (356 mS cm(-1)), may be clue to formation of interconnected network or channels in the membrane matrix. After embedding of aprotic IL (20 wt%; similar to 80 mu S/cm conductivity) in highly acidic polymer (BFC/Si-10). conductivity of BEC/Si-10/IL composite PEM was about 8.79 mS cm(-1) at 30 degrees C. High anhydrous conductivity for BEC/Si-10/IL PEM was attributed to the exchanged protons from highly acidic membrane matrix by IL cation. and accordingly a mechanism was proposed. Further, enhanced bound water content and thus slow dehydration of BFC/Si-x/IL composite PEMs, make them a promising candidate for fuel cell application under low humidification. (C) 2015 Elsevier B.V. All rights reserved,