Novel approach for the preparation of ionic liquid/imidazoledicarboxylic acid modified poly(vinyl alcohol) polyelectrolyte membranes

• Novel method of ionic liquid facilitated polyelectrolyte membrane preparation.
• Poly(vinyl alcohol) successfully modified by 4,5-imidazoledicarboxylic acid.
• Ionic membranes showed proton conductivity of 3.6 mS cm−1.
• Maximum current/power density obtained in Biogenerator was 1260 mA cm−2/245 mW cm−2.

This paper first time describes the preparation of the novel ionic proton exchange membrane (ILPEM). Ionic liquid, 1-butyl-3-methylimidazol-3-ium hexafluorophosphate, has immobilized into 4,5-imidazoledicrarboxyic acid (IDC) modified PVA matrix. ILPEMs optimized by measuring the swelling properties at varying cross-link time. Membranes were characterized to evaluate functional groups, % swelling, gel content, molecular weight between cross-link, cross-link density, thermal stability and proton conductivity. The single cell performances of the membrane evaluated using a microbial fuel cell set-up (Biogenerator). Ionic membranes exhibited higher thermal stability, and proton conductivity of the membrane obtained was in order of 2.8–3.6 mS cm−1. The Biogenerator equipped with ILPEM showed maximum current density of 1260 mA cm−2 and power density of 245 mW cm−2, which was higher than any of the existing conventional cathodic microbial fuel cell.