Bacterial cellulose biomass aerogels for oil-water separation and thermal insulation

The use of environment-friendly biomass for the preparation of functional materials has attracted increasing attention. In this study, bacterial cellulose (BC) was prepared from fruit waste via kombucha fermentation without involving any secondary enzymatic hydrolysis treatments. A three-dimensional network of bacterial cellulose aerogels (BCAs) with ultralow density (5.693 mg/cm 3 ), high porosity (98–99%), and low thermal conductivity (23.4 mW/(m·K)) were obtained using two directional freeze-drying techniques. Here, the proposed freezing method can not only control the concentration of BC but make access to fibres reassembly by extremely low temperature freezing (−196 °C), which can further form a multi-stage pore structure. To increase their compressive resistance and optimise their ability to adsorb organic solvents and oils, the aerogels were subjected to chemical vapour deposition using methyltrimethoxysilane. The modified biomass aerogel exhibits a compression resilience exceeding 90% and achieves a hydrophobic angle of approximately 146.4°. This cost-effective, environmentally friendly, and highly efficient BCAs can be employed to treat oil spills and industrial waste.