Robust superhydrophobic attapulgite meshes for effective separation of water-in-oil emulsions

Special-wetting materials have been broadly studied in various oil/water separation processes. However, there are granted numerous challenges in extremely durable materials with mechanical robustness, especially considering the great requirements in purifying emulsified oil/water mixtures. Herein, we present a facile route to prepare robust superhydrophobic surface by spraying Octadecyltrimethoxys modified attapulgite suspension combined with inorganic adhesive on mesh. The as-prepared meshes show eminent superhydrophobicity and acquire a gravity driven water-in-oil emulsion separation with efficiency above 99.7% and flux above 106.7 L m^-2h^-1 even after multiple cycles. In addition, the meshes exhibit robust and stable superhydrophobicity with water contact angles above 150° after 200 sandpaper abrasion (transverse shear force) and harsh sand impact (longitudinal impact force) cycles, and meanwhile, still maintain outstanding emulsion separation performance during tests. This study is meaningful for the development of fabricating low-energy separating materials with high efficiency and mechanical robustness for harsh chemical engineering.