pH-Responsive smart non-woven fabrics (NWFs) with double switchable wettability between superhydrophilicity-superhydrophobicity-superhydrophilicity to oil/water separation

摘要

pH-Responsive smart non-woven fabrics (NWFs) with double transformations were prepared via the in situ grafting of Ag nanoparticles through an oxidation-reduction reaction and were modified using a mixed thiol-molecule solution, including HS(CH2)(10)CH3, HS(CH2)(10)COOH and HS(CH2)(11)OH. A NWF continuously separates immiscible oil-water mixtures with high selectivity and has considerable flux under gravity. The wettability of NWFs with an optimal thiol concentration shows reversible switches between superhydrophilicity-superhydrophobicity-superhydrophilicity, which corresponds to different conditions such as acidic, neutral and basic. The as-prepared NWFs had great oil absorption capacities and possessed high oil-water separation efficiency. This simple approach to fabricate pH-responsive NWFs has provided a facile and versatile strategy for effectively separating oil-water mixtures, which can be further applied for water treatment, purification of solvents or fuels and so on.