Fabrication of anion-exchange composite membranes for alkaline direct methanol fuel cells

The quaternized poly(vinyl alcohol)/3-(trimethyl ammonium) propyl-functionalized silica (designated as QPVA/Q-SiO(2)) composite polymer membrane is prepared by a solution casting method. The Q-PVA is polyvinyl alcohol (PVA) derivatized with glycidytrimethyl ammonium chloride (GTMAC) and the Q-SiO(2) is 3-(trimethyl ammonium) propyl-functionalized silica. The highest ionic conductivity of the QPVA/20 wt.%Q-SiO(2) composite polymer electrolyte is sigma = 2.37 mS cm(-1) at ambient temperature. The alkaline direct methanol fuel cell (ADMFC) comprised of an anion-exchange QPVA/Q-SiO(2) composite embrane is assembled and examined. The highest peak power density of the DMFC with 8 M KOH + 2 M CH(3)OH fuel is 35.13 mW cm(-2) at 50 degrees C and 1 atm air. The peak power density is 0.27 mW cm(-2) with a pure 2 M CH(3)OH fuel at 25 C and 1 still air. (C) 2011 Elsevier B.V. All rights reserved.