Facile fabrication of environmentally friendly bio-based superhydrophobic surfaces via UV-polymerization for self-cleaning and high efficient oil/water separation

Bio-based superhydrophobic surfaces were created via photo-induced thiol-ene click reaction from a coating solution of castor oil-based thiolated oligomer (thiol - CO), 2, 4, 6, 8-tetramethyl-2, 4, 6, 8-tetravinylcyclotetrasiloxane and dodecyltrimethoxysilane-modified SiO2 nanoparticles. Thiol - CO was pre-synthesized by esterification reaction between CO and 3-mercaptopropionic acid. Spray-deposition of the coating solution onto various substrates (glass, fabric, mesh, paper and wood) followed by UV initiated polymerization created the hierarchical micro/nano-structured hybrid coatings with robust superhydrophobicity and superoleophilicity. The wetting behaviors of the hybrid coatings can be adjusted by changing the hydrophobic SiO2 nanoparticles loading. High water contact angle (similar to 160.5 +/- 1.1 degrees) and low sliding angle (similar to 1 degrees) were achieved with 40 wt SiO2 nanoparticles loading. In addition, the superhydrophobic coating shows self-cleaning ability with the excellent low adhesion to water. Furthermore, the environmentally friendly superhydrophobic surface deposited on stainless steel mesh is employed as a filter membrane for the separation of various oil/water mixture with a high separation efficiency and separation flux as well as great reusability. This facile fabrication strategy displays the advantages of renewable, sustainable, and scalable preparation of the multifunctional superhydrophobic coatings for self-cleaning and versatile oil/water separation applications.