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.

当下，寻求高效处理溢油与含油废水排放的方法已成为全球范围内的研究热点。本研究采用简便方法制备了一种超疏水涂层（superhydrophobic coating），其成分为十八胺接枝腐殖酸（humic acid grafted by octadecylamine），并将该涂层喷涂于多种不同基底之上，可实现自清洁、集油以及油/水混合物过滤等功能。此外，通过硅烷改性聚合物密封剂增强涂层与基底之间的粘附强度。经涂层处理的滤网展现出优异的超疏水性能（水接触角为153.14°）与超亲油性能（superoleophilicity，油接触角趋近于0°）。再者，该涂层滤网在油/水分离领域表现出色：油通量高达约16633.9 L·h⁻¹·m⁻²，分离效率超过95%，且具备良好的可重复使用性（可循环使用10次以上）。进一步而言，涂层滤网的孔径可通过调整涂层循环工艺次数进行调控，当滤网具备微孔孔径时，可实现油包水乳液的分离。综上，这种十八胺接枝腐殖酸型超疏水涂层具备上述诸多优异性能，在高效油/水分离领域展现出巨大的应用潜力。