Fish-scale nickel mesh with switchable wettability for efficient oil/water separation

Abstract

In the daily life of human beings, sewage discharge and oil spill accidents occur from time to time. New types of controllable oil/water separation interface materials have received more attention. In this study, we proposed a simple and environmentally friendly method to prepare a Nickel filter with switchable wettability. The final product is prepared by high temperature calcination and soaked with stearic acid ethanol solution. The prepared filter screen has selective separation performance for oil/water mixture with switchable surface wettability between superhydrophobic and superhydrophilic. The separation efficiency is higher than 99.50%, and the flux rate is as high as 46.25 L m−2s−1 for water-removing process and 40.22 L m−2s−1 for oil-removing process. The wettability conversion of the membrane can be achieved through heating treatment and soaking treatment, and it still has good oil/water separation performance. After 20 times of cycles, the separation efficiency remains unchanged, and the flux remain above 40.06 L m−2s−1 for oil removal and 36.81 L m−2s−1 for water removal process. The results show that the prepared nickel filter screen has good practical application prospects such as water reclamation and oil spill treatment.