Oleophobicity of Chitosan/Micron-alumina-Coated Stainless Steel Mesh for Oil/Water Separation

In this research, stainless steel meshes coated with chitosan and micron-alumina were prepared via a dip-coating method. The coated mesh exhibits underwater oleophobic property with low oil adhesion. The influence of different concentrations of chitosan and micron-alumina on underwater oil contact angle of the coated mesh was studied. The separation efficiencies of the coated mesh for different oil–water mixtures were also tested. The results showed that the underwater oil contact angle of the coated mesh was as high as 146° when the concentrations of chitosan and micron-alumina were 0.4 and 0.04 wt%, respectively. The coated mesh can separate different kinds of oil with an efficiency over 90 % in gravity-driven method. Furthermore, the mesh has high recyclability in the application of oil–water separations in both NaCl and weak alkaline solutions. The chitosan and micron-alumina coated mesh has potential applications in oil–water separations. Graphical abstract The chitosan and micron-alumina modified stainless steel meshes show an underwater oil contact angle of 146° and a efficiency over 90 % for gravity-driven oil/water separation.