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Surface Design of Separators for Oil/Water Separation with High Separation Capacity and Mechanical Stability

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journal contribution
posted on 2017-07-11, 00:00 authored by Yong Taek Lim, Nara Han, Wooree Jang, Wooyoung Jung, Min Oh, Seung Whan Han, Hye Young Koo, Won San Choi
A convection heat treatment that can replace existing chemical oxidation methods was developed for the preparation of hierarchically oxidized Cu meshes with various surface morphologies, representing a very simple and green route that does not involve toxic chemicals. Three types of Cu meshes [bumpy-like (BL) and short and long needle-like (NL) structures] exhibited similar separation efficiencies of 95–99% over 20 separation cycles, as indicated by their similar water contact angles (WCAs; 147–150°). However, these Cu meshes exhibited different flux behaviors. Excessively rough and excessively smooth surfaces of the Cu mesh resulted in increased resistance to flow and to a decrease of the penetration of oil. A surface with intermediate smoothness, such as the BL-Cu mesh, was necessary for high flux over a broad range of oil viscosities. Furthermore, a less rough surface was more suitable for the separation of highly viscous oil. Computational fluid dynamics (CFD) simulations were carried out to support our experimental results. The BL-Cu meshes also showed outstanding mechanical stability because of their low resistance to the flow of fluids.