Functional bacterial cellulose membranes with 3D porous architectures: Conventional drying, tunable wettability and water/oil separation

Bacterial cellulose (BC) membranes have been widely used in many fields because of their biodegradable, biocompatible and renewable nature. To maintain their pristine 3D porous architectures, however, complex and time-consuming drying processes such as supercritical CO2 drying and freeze drying have to be employed. Herein, we demonstrated that BC skeletons modified by hydrolyzing of alkoxysilanes were sufficiently robust to remain the porous architectures via conventional drying. In addition, the surface wettability of the as-formed membranes could be easily modified by tuning the composition of alkoxysilanes in the hydrolyzing step. The combination of the special wettability and the proper pore size endow the membranes the ability to separate both surfactant-stabilized water-in-oil and oil-in-water emulsions with high efficiency. The simple and scalable modification method promises BC membranes potential applications in emulsion separation, fuel purification and wastewater treatment.