Robust, fluorine-free and superhydrophobic composite melamine sponge modified with dual silanized SiO2 microspheres for oil–water separation

Massive oily wastewater discharged from industrial production and human daily life have been an urgent environmental and ecological challenge. Superhydrophobic materials have attracted tremendous attention due to their unique properties and potential applications in the treatment of wastewater. In this study, a novel superhydrophobic/superoleophilic composite melamine sponge modified with dual silanized SiO 2 microspheres was fabricated simply by a two-step sol–gel method using vinyltriethoxysilane and hexadecyltrimethoxysilane as functional agent, which exhibited a water contact angle of 153.2° and a water sliding contact angle of 4.8°. Furthermore, the composite sponge showed the excellent oil adsorption performance and the compressive elasticity reaching up to 130 g·g −1 of dichloromethane and 33.1 kPa of compressive stress. It was worth noting that the composite sponge presented the excellent separation efficiency (up to 99.5%) in the processes of continuous oil/water separation. The robust superhydrophobic composite melamine sponge provided the possibility with the practical application for oil–water separation.