Sustainable and Biodegradable Superhydrophobic Coating from Epoxidized Soybean Oil and ZnO Nanoparticles on Cellulosic Substrates for Efficient Oil/Water Separation

Conventional superhydrophobic materials for oil/water separation were usually prepared from nondegradable and nonrenewable resources, which would not only increase resource crisis but also cause environmental pollution after discarding. In this study, we report a renewable and biodegradable superhydrophobic material, which was fabricated via a two-step curing dip-coating method and was composed of cellulosic filter paper or fabric, cured epoxidized soybean oil (CESO), ZnO, and stearic acid (STA) as the substrate, adhesive, rough structure, and low energy modifier, respectively. The CESO combined ZnO nanoparticles with cellulosic substrate tightly to show excellent stability when suffering from immersing in water and oil for 7 days without losing superhydrophobicity. When the superhydrophobic coating was constructed onto the surface of cellulosic fabric, the material showed high separation efficiency with the values higher than 97% during separation of various oil/water mixtures. The sustainable and biodegradable superhydrophobic material may find potential application in efficient oil/water separation without creating material waste after throwing away.