Cellulose acetate-based SiO2/TiO2 hybrid microsphere composite aerogel films for water-in-oil emulsion separation

The cellulose acetate (CA)/SiO 2 -TiO 2 hybrid microsphere composite aerogel films were successfully fabricated via water vapor-induced phase inversion of CA solution and simultaneous hydrolysis/condensation of 3-aminopropyltrimethoxysilane (APTMS) and tetrabutyl titanate (TBT) at room temperature. Micro-nano hierarchical structure was constructed on the surface of the film. The film could separate nano-sized surfactant-stabilized water-in-oil emulsions only under gravity. The flux of the film for the emulsion separation was up to 667 L m −2  h −1 , while the separation efficiency was up to 99.99 wt%. Meanwhile, the film exhibited excellent stability during multiple cycles. Moreover, the film performed excellent photo-degradation performance under UV light due to the photocatalytic ability of TiO 2 . Facile preparation, good separation and potential biodegradation maked the CA/SiO 2 -TiO 2 hybrid microsphere composite aerogel films a candidate in oil/water separation application.