Stable superhydrophobic and superoleophilic silica coated polyurethane sponges for the continuous capture and removal of oils from the water surface

Abstract

The removal of oil and organic pollutants from water is highly desired due to the frequent oil spill accidents, as well as the increase of industrial oily wastewater. In this work, we demonstrate a simple method for the collection of oils and organic solvents from the water surfaces based on hydrophobic SiO₂ coated polyurethane sponges (SiO₂-PU-sponge) that were fabricated by a facile solution-deposition process. The SiO₂-PU-sponge could quickly and selectively absorb various kinds of oils up to 55.8 times its own weight. In addition, the superhydrophobic SiO₂ coated sponge retains its high absorption capacity even under harsh conditions, such as high temperatures and corrosive solutions. Furthermore, the SiO₂-PU-sponge connected with a vacuum system could remove a great amount of oils – up to 32 000 times its own weight. Such a SiO₂ coated sponge is an effective approach for the large-scale capture of oils and organic pollutants in the future.