Controllable process to construct robust superhydrophobic membrane with tunable pore size for efficient separation of oil-water mixtures and emulsions

Abstract

The increase in the discharge of industrial oily wastewater poses a threat to the environment and human health. Thus, the treatment of oily wastewater has become a focus of current research. The superhydrophobic surface derived from the lotus effect provides an effective direction for oil-water separation. Based on this, the authors reported a tunable superhydrophobic stainless steel separation mesh with a water contact angle of 155° through simple electrodeposition and modification with a fluorine-free modifier. The separation mesh with different surface morphology, by controlling different electrodeposition time and current, is able to achieve oil-water separation with super flux up to 51561 L/(m2·h) in heavy oil/water mixture and high-efficiency over 99.5% in water-in-oil emulsion. This controllable process constructs superhydrophobic membrane with tunable pore size, which is capable of separating heavy oil/water mixtures and water-in-oil emulsions depending on the process. This proposal is suggestive in the field of oil-water separation.