Improving the Proton Conductivity and Antibacterial Properties of Sulfonated Polybenzimidazole/ZnO/Cellulose with Surface Functionalized Cellulose/ZnO Bionanocomposites

New bionanocomposite proton exchange membranes were prepared from sulfonated polybenzimidazole (s-PBI) and various amounts of sulfonated ZnO/cellulose nanohybrids (ZnO/cellulose-SO3H). The use of ZnO/cellulose-SO3H compensates for the decrease in ion exchange capacity of membranes observed when non-sulfonated nano-fillers are utilized. The strong –SO3H/–SO3H interaction between s-PBI chains and ZnO/cellulose-SO3H hybrids leads to ionic cross-linking in the membrane structure, which increases both the thermal stability and methanol resistance of the membranes. The ZnO/cellulose -SO3H in the membranes served as spacers for polymer chains to provide extra space for water permeation, so as to bring high permeation rates to the complex membranes. Moreover, the membranes exhibited excellent antibacterial activities against S. aureus and E. coli. A.