Wettability-switchable bacterial cellulose/polyhemiaminal nanofiber aerogels for continuous and effective oil/water separation

Wettability-switchable bacterial cellulose/polyhemiaminal nanofiber aerogels were successfully prepared by a facile in situ polymerization of paraformaldehyde and 4,4′-diaminodiphenyl ether. The resultant aerogels displayed an interconnected porous structure, superior porosity, low density as well as hydrophobic–oleophilic properties. The aerogels could not only quickly and efficiently absorb the variety of oils or organic solvents from water, but also completely release the adsorbates in acid aqueous solutions by the aid of wettability switch (from hydrophobicity–oleophilicity to underwater superoleophobicity). Furthermore, the aerogels can continuously collect oils both on the water surface and in water-in-oil emulsions by a peristaltic pump.