Hybrid membranes of PVA for direct ethanol fuel cells (DEFCs) applications

Proton-conducting hybrid membranes composed of poly(vinyl alcohol) (PVA), phosphotungstic acid (HPW) and (diethylenetriamine)pentaacetic acid (DTPA) where prepared. The effect of HPW doping and crosslink with DTPA on the membranes properties such as uptake, pervaporation and proton conductivity was investigated. Uptake and permeated flux decreases with increasing content of HPW and DTPA. Ethanol permeabilities obtained was about two orders of magnitude smaller than Nafion® 117. FTIR spectra indicated that HPW was incorporated into the polymer matrix and DTPA acted as crosslink agent. The proton conductivity was in the order of 10−3 S cm−1 with added 4 wt.% of DTPA and generally increases with the addition of HPW.