Fabrication of special wettability functionalized Mg(OH) 2 @cotton fabric for oil/water mixtures and emulsions separation

In recent years, inspired by the structure of natural lotus leaves and fish scales, the oil/water separation membrane with special wettability has made remarkable progress. A cost-effective, eco-friendly and facile approach of membranes with special wettability performance is highly desired. Herein, magnesium hydroxide (Mg(OH)2) is synthesized in situ on cotton fabrics through a surface micro-dissolution method to prepare superhydrophilic and underwater superoleophobic functionalized fabrics. Driven by gravity, the Mg(OH)2@fabric can successfully separate the oil/water mixture with high flux of 3027–4137 L/m2 h and high separation efficiency of 99.5%. In addition, after soaking in harsh environment for 72 h, such as alkali and salt solution, it still has high stability and can be used as a membrane to separate a series of oil/water mixtures. Driven by a constant current pump (200 mL/min), the developed fabric can separate oil-in-water emulsions with a high separation efficiency of 99.5%. After 50 cycles, the separation efficiency of the treated fabric for oil–water mixture is more than 99.3%, and the underwater contact angle is more than 156.6°. This method can simply and effectively produce fabrics that can be used to treat water purification and oily wastewater, and has a broad application prospect.