SnO_2-ionomer composites: a comparative study of the transport properties

摘要

Composite membranes were prepared using hydrated tin oxide as filler and either Nafion or sulfonated poly sulfone (SPS) as ionomers. The filler content ranged between 5 and 35 wt.%. The ion exchange capacity (IEC) values of the membranes, as well as their proton conductivity (a) and water uptake properties, were determined by means of potentiometric titrations, electrochemical impedance spectroscopy (EIS) and dynamic vapor sorption (DVS). The effect of the filler on the ionomer properties was found to be strongly dependent on the ionomer microstructure. Such effect resulted to be particularly important for SPS membranes, whose proton conductivity was improved al low RH as the filler content increased.