Eco-friendly and scratch-resistant hybrid coating on mesh for gravity-driven oil/water separation

Abstract

Abstract Oil/water separation by the membranes with unique wetting behavior has been widely reported. Unfortunately, many approaches can cause secondary contamination because of the use of toxic solvents and coating materials. In this work, a new type of underwater superoleophobic mesh with natural attapulgite nanorods (APT) coating was successfully constructed via an eco-friendly bioadhesion method. The decorated mesh possesses satisfactory superoleophobicity not only in its initial state, but after being treated by highly corrosive aqueous solutions containing acid, alkaline or salt as well as strongly mechanical scraping. The mesh prewetted with water is able to filtrate a series of the mixtures of light oil and water with the separation efficiency over 97.5%. It is also demonstrated that the mesh has good recyclability and quick separation rate in oil/water separation. Especially, a gravity driven oil/water filtration for the oils in hot (90 °C) acidic, caustic and salty water environments can be achieved using the as-constructed mesh, and the separation efficiencies are more than 97.8%. Because of facile and eco-friendly preparation process as well as durably underwater superoleophobicity, the decorated mesh is potentially useful in the treatment of oily wastewater.