Fabrication Of Bio-inspired Cellulose Based Aerogel For Oil/Water Separation

Nowadays, the frequent oil spillages and the industrial discharge of oil/water emulsifications have harmed the environment, human health, and the growth of plants and animals immensely. Therefore, oil/water separation is becoming more topical in daily life and industrial and agricultural production. Special wettable materials exhibit high oil/water separation efficiency, which have attracted increasing attention recently. However, special wettable materials have higher prices. Cellulose is one of natural polymeric materials, which have attractive features such as low cost, renewability, biocompatibility, nontoxic and biodegradability. In our paper, we prepared cellulose aerogel for oil/water separation, and aerogel have special wettable. The main contents are as follows:(1) We choose medical absorbent cotton as cellulose and Na OH/Urea/H2 O as cellulose solvent. Firstly, cellulose aerogels was prepared through sol-gel method and freeze-drying process. Then, a thin layer of Fe3O4 was coated on cellulose aerogel surface to increase the roughness of cellulose aerogel. At last, aerogel was modified by hexadecyltrimethoxysilane to increase hydrophobic of aerogel. The property of cellulose aerogel was chartered by SEM、XPS、Contact angel and so on. The results showed that the surface of cellulose aerogel possess micro-nanostructure and superhydrophobicity. Cellulose aerogel could separate oil-water mixtures with a high separation efficiency and good reusability.(2) Cellulose have a similar structure with chitosan and they have good compatibility. On the surface of chitosan aerogel grow number micron-diameter particles. Cellulose have high mechanical strength. Based on the property of cellulose and chitosan we prepared cellulose/chitosan composite aerogel. Firstly, we prepare cellulose solution and chitosan solution. Then, cellulose/chitosan composite aerogel was prepared through sol-gel method and freeze-drying process. At last, composite aerogel was modified by hexadecyltrimethoxysilane to increase hydrophobic of aerogel. The result showed that the surface of composite aerogel had micro-nanostructure and superhydrophobic. Composite aerogel could separate oil-water mixtures with a high separation efficiency and good reusability.(3) Cellulose/chitosan composite aerogel have the property of hydrophobic. We added epichlorohydrin in cellulose/chitosan composite aerogel to improve the hydrophilicity of composite aerogel. The results indicated hydrogen bonding network structure of cellulose and chitosan was destroyed and more hydrophilic groups(-OH) was exposed. Composite aerogel had the property of superhydrophilicity, underwater superoleophobicity and self-cleaning. Composite aerogel can separate free oil/water mixture and surfactant-stabilized oil in water emulsions with high separation efficiency.