A facile approach for preparation of underwater superoleophobicity cellulose/chitosan composite aerogel for oil/water separation

We fabricate cellulose/chitosan (CE/CS) aerogel with stable superhydrophilic ( θ ≈ 0°) and underwater superoleophobic ( θ oil > 150°) through a simple way. During the process of preparation of CE/CS aerogel, chitosan will self-assemble into number micron diameter particles on the surface of aerogel. Furthermore, the hydrogen bonding network structure of cellulose was destroyed and more hydrophilic groups (–OH) were exposed. Rough surface and hydrophilicity make CE/CS aerogel have a property of underwater superoleophobicity. CE/CS aerogel shows underwater superoleophobicity to different oils, and it still have stable superoleophobicity in corrosive solution. The important thing is that CE/CS aerogel can separate free oil/water mixture and surfactant-stabilized emulsions under gravity effectively. The sample is green, low cost, and environmental friendly, which is a promising candidate to be used in oil/water separation.