Fabrication of durable superhydrophobic and superoleophilic cotton fabric with fluorinated silica sol via sol-gel process

Superhydrophobic and superoleophilic cotton fabric was successfully prepared with fluorinated silica sol via a facile sol-gel method. A fluorinated polymeric sol-gel precursor (PHFBMA-MTS) was synthesized via free-radical polymerization by using hexafluorobutyl methacrylate (HFBMA) in the presence of (3-mercaptopropyl)trimethoxysilane (MTS) as the chain transfer agent, which led to the formation of fluoropolymer with alkoxysilane end groups. Then the fluorinated silica sol was prepared by introducing PHFBMA-MTS as the co-precursor of tetraethylorthosilicate (TEOS) in the sol-gel process with ammonium hydroxide as the catalyst, which was then used to fabricate superhydrophobic and superoleophilic fabric coatings through a simple dip-coating method. The coated fabrics showed superhydrophobic property with a high water contact angle of 154.1 degrees and superoleophilic property with an oil contact angle of 0 degrees. Moreover, the coated fabrics still kept superhydrophobicity even after ultrasonic treatment, as well as for organic solutions, acidic solutions. Thus, the coated fabrics were successfully applied to separate oil-water mixture with separation efficiency up to 99.8%. More importantly, the separation efficiency had no significant change after 20 cycles of oil-water separation. These present a simple, low-cost, and durable approach to achieve industrialized application of coated fabrics in oil-water separation. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47005.