Sulfonated bacterial cellulose/polyaniline composite membrane for use as gel polymer electrolyte

Gel polymer electrolyte (GPE) with high ionic conductivity and stable electrochemical characteristics have great importance to the application in fuel cells, biological cells and other fields. In this study, bacterial cellulose (BC) was firstly modified by sulfonation to get sulfonated BC (SBC) for the first time. Then a novel sulfonated BC/polyaniline (SBC/PANI) composite GPE was synthesized in situ by oxidative polymerization of aniline onto SBC nanofibers successfully. The structure, microstructure, thermal stability and electrochemistry property of the SBC/PANI composite GPEs were tested and compared. The results showed that the ionic conductivity and ion exchange capacity of the SBC/PANI composite GPEs were associated with the degree of sulfonation (DS). At the DS of 41.87%, the ionic conductivity and ion exchange capacity could be improved to 5.2 × 10−3 S cm−1 and 3.92 mequiv. g−1, respectively. The electrochemical stability window could meet the application requirement of a variety of biocells and fuel cells. The cytotoxicity of the composites was also evaluated using cell counting kit-8 (CCK-8) assay in vitro and turned out that mesenchymal stem cells (MSCs) could adhere to the surface of the membrane and proliferate normally.