Improved mechanical and thermal properties of bacterial cellulose with the introduction of ionic liquid

Bacterial cellulose (BC) is a natural polymer secreted by microorganisms with excellent tensile strength (TS) and Young’s modulus (YM). However, the elongation at break (EAB) and toughness (TH) of dehydrated BC membranes are inadequate for some special applications. In this study, ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) was introduced into BC membranes to fabricate composite membranes. It was found that AmimCl could dissolve the BC nanofibers to a certain extent, and destroy the hydrogen bonds between the protofibrils. Therefore, compared with pure BC membrane, BC/AmimCl composite membranes exhibited improved EAB and TH. In addition, AmimCl had a positive effect on the thermal stability and transparency of the composite membranes. This study shows that ionic liquids have great potential to change the mechanical properties, optical properties and thermal stability of BC membranes.