Facile fabrication of superhydrophobic fly ash-coated mesh for oil-water separation

The pollution of water by oil is a global challenge. In this study, the design and fabrication of a superhydrophobic stainless steel mesh are reported. This was achieved through a sample "glue + fly ash" fabrication method. The fly ash was first modified by a stearic acid solution impregnation method. After the modification, the fly ash was then bonded to the surface of a stainless-steel mesh by an epoxy resin solution to obtain the superhydrophobic mesh. The introduction to the modified fly ash endows the mesh with excellent corrosion resistance and superhydrophobicity when compared with the original mesh. The as-prepared mesh could separate various oil and organic solvents from water with a separation efficiency exceeding 98%. Interestingly, the oil separation capacity of the as-prepared mesh still kept a high value after 30 cycles of reuse. The simplicity, eco-friendliness and low cost of this method turn it into a practical and realistic approach to the large-scale fabrication of superhydrophobic surfaces. These properties make the as-prepared mesh an ideal candidate for actual oily wastewater treatment.