Preparation of smart and reversible wettability cellulose fabrics for oil/water separation using a facile and economical method

Successful fabrication of smart membrane based on cellulose fabric for controllable oil/water separation was reported. Sheet hexagonal ZnO was in situ synthesized on surface of cellulose fibers using NaOH/urea and ZnCl2 aqueous solution which were also exploited to fix ZnO steadily due to their swelling and dissolving effects on cellulose. Reversible wettability transition between superhydrophobicity/superoleophilicity and superhydrophilicity/superoleophobicity underwater was manipulated easily by dipping into a lauric acid ethanol solution and NaOH/ethanol water solution in turn for 2min. In detail, the as-prepared functionalized membranes can separate weight or light oil/water mixtures with separation efficiency higher than 98% of water removing and 96.5% of oil removing and high oil flux of 2900-3200 L h−2 m-2 and water flux of 3100-3400 L h−2 m−2. Simultaneously, the modified fabrics exhibited good stability and excellent recyclability via 20 times cycle operations of wettability transition and separation.