Fluoroalkylsilane/Nafion® composite electrolyte membranes

FAS (fluoroalkylsilane)/Nafion® composite electrolyte membranes were successfully fabricated through a sol-gel method. The FAS consisting of a hydrophobic functional group and silanol ligands is impregnated in a Nafion® membrane. The prepared FAS/Nafion composite electrolyte membranes (FNCMs) containing hydrophobic FAS-derived silicate nano-particles in a Nafion® matrix showed a decrease in methanol crossover and a reduction in the humidity dependence without a large sacrifice of proton conductivity. The characteristics of the composite membranes, such as the microstructure, proton conductivity, solvent uptake and expansion rate, were investigated. Fuel cell operating tests were also performed using the prepared modified Nafion® membranes.