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 (theta approximate to 0 degrees) and underwater superoleophobic (theta(oil) > 150 degrees) 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.