Hydrophobic Aerogel from Cotton Pulp: Reusable Adsorbents for Oil/Organic Solvent-Water Separation

In this work, regenerated cellulose aerogels were prepared and modified by vapour phase deposition to obtain hydrophobic cellulose aerogels for oil-water separation. The cotton pulpboard was dissolved in the NaOH/urea/water system. Then the cross-linking agent N, N-methylene bisacrylamide (MBA) was added to the cellulose solution and cross-linked to obtain a hydrogel with controllable structure and performance, freeze-dried to form a regenerated cellulose aerogel. The regenerated cellulose aerogels were modified with Metyltrimethoxysilane (MTMS) and Fe3O4 nanoparticles to produce magnetic hydrophobic regenerated cellulose aerogels. Magnetic hydrophobic regenerated cellulose aerogels have more than 95% porosity with an ultra-light structure. The aerogel exhibited superior oil/water selectivity and high oil/water absorption (62.16-79.89 g/g) for various oils and organic solvents. The cycle test showed that the aerogel could be recycled more than ten times, and the adsorption capacity did not decrease obviously.