Preparation and characterization of PTFE based composite anion exchange membranes for alkaline fuel cells

In this paper, we report on the preparation of a novel type of PTFE based composite anion exchange membrane for alkaline fuel cells by a low-toxic and facile processing route. The membranes were synthesized by in-situ polymerization of a N-vinylformamide monomer in the PTFE matrix, followed by hydrolysis in sodium hydroxide aqueous solution and quaternary amination with iodomethane-ethanol solution. The method for anion exchange membrane synthesis is facile, low-toxic and does not involve the use of carcinogenic chemical such as chloromethylmethylether and trimethylamine. The membranes were characterized via Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Water uptake, ionic exchange capacity, tensile strength and conductivity have also been investigated to evaluate the performance in alkaline fuel cell. The results showed that the membranes exhibited high ionic exchange capacity, as well as good mechanical, chemical and thermal stabilities.

► A novel anion exchange membrane is prepared by a facile and green procedure. ► The fabrication route is simple and feasible to avoid chloromethylation. ► SEM results indicate that pores of PTFE membrane are completely filled.► The membrane has good thermal stability and is stable in 1 M KOH at 60 °C.