Facile fabrication of durable superhydrophobic SiO2/polyurethane composite sponge for continuous separation of oil from water

Abstract

Superhydrophobic porous materials have great potential for oil absorption due to their good stability, high absorption capacity and recyclability. Herein, a simple one-step solution immersion method was employed to fabricate a robust superhydrophobic polyurethane sponge by anchoring hydrophobic SiO₂ nanoparticles into a porous polyurethane frame. The durability of the resultant sponge was studied by repeated abrasion tests and immersion in concentrated acid and alkali solutions. After 100 abrasion cycles and strong acid/alkali immersion, the superhydrophobic polyurethane sponge still showed good repellence to water. Importantly, the obtained polyurethane sponge could be used for continuous separation of oil pollutants from the water surface quickly and effectively, making it a promising candidate material for use in oil-spill cleanups.