Preparation and properties of bacterial cellulose/polypyrrole/fluorinated graphite flexible conductive membranes

Abstract

Bacterial cellulose （BC）-based flexible conductive membrane materials have garnered significant attention in current research due to their exceptional mechanical properties， excellent biocompatibility and environmentally friendly processing technology. These materials feature a three-dimensional mesh structure with numerous hydroxyl groups on the BC fibers. However， this structural characteristic can lead to the absorption of bound water， negatively impacting charge transport. To address this issue， researchers have developed flexible conductive composite membrane materials （BC/PPy/PVA-nFG） through in-situ polymerization and vacuum filtration. In this composite， polyvinylalcohol （PVA） serve as the mechanical reinforcement component， polypyrrole （PPy） act as the conductive phase and fluorinated graphite （FG） provide hydrophobic properties as well as conductivity. By reducing the hydrogen bonding between water molecules and the hydroxyl groups on the BC fibres， the content of bound water is effectively minimized， thus enhancing the charge transport stability even in wet conditions. Experimental data reveal that the initial resistance of the dry-state flexible conductive material is 32 Ω. Upon water absorption， the resistance increases to 47 Ω at the water absorption reach 53%， demonstrating the efficacy of incorporating cost-effective FG nanosheets. This research opens up valuable avenues for developing a new generation of green and environmentally friendly flexible conductive membrane materials.