Novel proton-conducting materials based on a polyethylene terephthalate track-etched membrane modified with an N, P-containing ionic liquid

The development of novel membrane materials for hydrogen fuel cells, a promising environmentally friendly technology, represents a relevant research task. In this work, we propose an approach to creating proton-conducting membranes from an industrial polyethylene terephthalate (PET) dielectric track-etched film. An N, P-containing ionic liquid was used as a modifying agent, whose polymerization was carried out directly in the PET membrane pores. The ionic liquid was obtained using a novel approach to the directed synthesis of organophosphorus compounds from elemental phosphorus via the Trofimov-Gusarova reaction developed at the A.E. Favorsky Institute of Chemistry of the Siberian Branch of the Russian Academy of Sciences. The ionic liquid properties were characterized by NMR and IR spectroscopy. The application of the obtained N, P-containing ionic liquid onto a PET membrane was shown to yield a material exhibiting the required mechanical parameters for operation as proton-conducting membranes. The novel proton-conducting materials demonstrate a high proton conductivity of 77.76 mS·cm-1 at 353 K. The obtained proton-conducting membranes seem promising for application in hydrogen fuel cells, thus contributing to the development of effective alternative energy sources.