Nafion based nanocomposite membranes with improved electric and protonic conduction

In this work, a stable aqueous dispersion solution of polymer-modified graphene was prepared by in situ reduction with ethylene glycol from graphene nanosheets (GNs) in the presence of poly (diallyldimethylammonium chloride) (PDDA), in order to obtain a (PtNPs–GNs–PDDA) nanocomposite material, where Pt nanoparticles (PtNPs) with a narrow size distribution of 2–4 nm uniformly decorates GNs, being both embedded into the PDDA. The multilayer films consisting of this new nanocomposite material and a common negatively charged polyelectrolyte (PSS) were fabricated on Nafion NRE 212 membrane applying the versatile layer-by-layer (LbL) self-assembly technique. Both morpho-structural (HR-TEM, FEG-SEM, AFM, UV–vis spectroscopy, ATR-IR spectroscopy, ELS) and charge transport characteristics (EIS) were analyzed during the assembling process showing that the new nanocomposite membrane presents an improved electrical conduction without a major alteration of the protonic one. The results may open new areas of applications, from proton exchange membrane fuel cells to biosensors.