Chemically stable superhydrophobic polyurethane sponge coated with ZnO/epoxy resin coating for effective oil/water separation

In this study, a superhydrophobic polyurethane sponge was prepared by a simple immersion method. The strategy was based on coating a ZnO/epoxy resin solution onto the skeleton of a porous polyurethane sponge, followed by reacting it with a mixture of stearic acid/acetic acid/ethanol solution. The prepared super hydrophobic polyurethane sponge with a contact angle of 156 +/- 3 degrees can selectively separate mixtures of water and various oily solvents. The separation efficiencies of the superhydrophobic polyurethane sponge for a variety of oil/water mixtures were all above 98 %. Moreover, the prepared superhydrophobic polyurethane sponge had superior reusability and maintained a separation efficiency of more than 97 % after ten oil/water separation cycles, and it was chemically stable from pH 1-11. This superhydrophobic polyurethane sponge may offer a new oil/water separation strategy due to its excellent separation efficiency, reusability, and chemical stability.

Automated summary

The superhydrophobic polyurethane sponge prepared in this study showed excellent separation efficiency, reusability, and chemical stability for oil/water mixtures.