Highly efficient oil–water separation using superhydrophobic cellulose aerogels derived from corn straw

Abstract

Cellulose-based aerogels have become promising adsorbents for organic pollutants and spilled oil due to their high selectivity and excellent sorption capacity. However, the high costs of preparation limit their practicality. In this study, cellulose fibers were fabricated from corn straw via simple alkaline pulping and bleaching. A cellulose aerogel (CA) was then prepared by the freeze-drying method with polyvinyl alcohol as the binder. After treatment with methyltrimethoxysilane by facile chemical vapor deposition, a modified cellulose aerogel (MCA) with water contact angles up to 154.8° was obtained, which exhibited superhydrophobicity. Importantly, the MCA has both high porosity (98.35–98.94%) and low density (16.33–23.95 mg·cm−3). In addition, the MCA can separate oil–water mixtures by gravity filtration with separation efficiency up to 97.3% and flux as high as 9827 L·m−2·h−1. This conversion of agricultural wastes into an efficient and high value-added adsorbing material is a promising development in the field of oil–water separation that offers a green and efficient strategy to combat the leakage of organic solvents and oil into the environment.

Keywords

• corn straw
• cellulose aerogel
• superhydrophobic
• oil/water separation
• chemical vapor deposition