Facile fabrication of versatile superhydrophobic coating for efficient oil/water separation

Nowadays, finding an efficient way to treatment oil spill and oily wastewater emission has attracted much attention all over the world. In this work, we fabricated a superhydrophobic coating (humic acid grafted by octadecylamine) with a simple method, and sprayed this coating on different structures which apply for self-cleaning, collect oil, and filter oil/water mixtures. In addition, silane-modified polymer sealant was used to strengthen the adhesive attraction between coating and structures. The coated mesh exhibited excellent superhydrophobicity (water contact angle of 153.14°) and superolephilicity (oil contact angle near 0°). Moreover, the coated mesh displayed outstanding performance in oil/water separation with huge oil flux about 16633.9 L h−1 m−2, high separating efficiency more than 95%, and good reusability (more than 10 cycles). Furthermore, the pore size of the coated mesh could regulate by changing the cycle of coated process, and the micro pore size of mesh could realize water-in-oil emulsions separation. To sum up, these merits of the superhydrophobic humic acid grafted by octadecylamine coating displayed great potential for effective oil/water separation.