Biomimetic Mineralization to Fabricate Superhydrophilic and Underwater Superoleophobic Filter Mesh for Oil–Water Separations
Rui Liao, Kui Ma, Siyang Tang, Changjun Liu, Hairong Yue, Bin Liang
Abstract
A filter mesh was prepared by a facile biomimetic mineralization method with excellent superhydrophilic and underwater superoleophobic properties for the gravity-driven oil–water separations. It shows extremely high permeation flux (>440 kL·m–2·h–1), excellent cycling ability, and high separation efficiency with a chemical oxygen demand (COD) of the filtrate lower than 9 mg/L in several typical oil–water separation processes. The filter mesh also exhibits significant long-term stability of underwater superoleophobic property in the neutral and strong alkaline chemical environment. For instance, it exhibited stable surface oil contact angles (>160°) and high separation efficiency (COD < 7 mg/L) after separating the kerosene-water mixtures with a pH of 7–13. In addition, the liquid wetting models were established to understand the function mechanism of superhydrophilic and underwater superoleophobic surfaces on the oil–water separation.