Swan feather-spired fluorine-free superhydrophobic self-cleaning cotton cloth with strong oil-water separation function

Abstract

With the increasing demand of oil-water separation, superhydrophobic materials have garnered tremendous research attention due to their excellent oil-water separation efficiency. However, the biological toxicity and poor durability of fluorine-containing compounds in superhydrophobic materials severely restrict their application. In this work, inspired by the superhydrophobic/lipophilic swan feathers, we proposed a two-stage thiol-ene click reaction strategy to fabricate a fluorine-free superhydrophobic and super-lipophilic oil/water separation membrane (Cotton-S-PB-SiO2). Firstly, based on this thiol-ene click reaction, the rubber molecular chain 1,2-polybutadiene (1,2-PB) with low surface energy was coated with cotton fiber through chemical bonds. Subsequently, the coated cotton fiber was employed to establish chemical bonds with silica. The Cotton-S-PB-SiO2 possessed low surface energy and abundant micro-nano structures. Meanwhile, the Cotton-S-PB-SiO2 showed extremely high wettability selectivity to water and oil phases. The flux reached 44,554 L m−2 h−1, and the separation efficiency for immiscible oil/water mixtures was above 99.9 %. More remarkably, the Cotton-S-PB-SiO2 demonstrated excellent anti-fouling and operation stability even under some harsh environments such as strong acid, alkali, salt, etc. The prepared self-cleaning cotton cloth provides insights toward mild, low-cost and high-efficiency oil-water separation.