The preparation of antifouling and superhydrophobic polyurethane sponge by grafting Econea to diisocyanate monomer for durable continuous oil/water separation and cleanup of oil spills

Abstract

The oil-absorbent sponge is effective in the prevention and cleanup of offshore oil spills. However, biofouling in marine environments will significantly reduce its oil absorption capacity. Herein, a novel type of antifouling and superhydrophobic polyurethane (PU) sponge was successfully prepared via grafting Econea (antifouling agent) to diisocyanate monomer and hydrophobic modification of PDMS (Polydimethylsiloxane) and SiO2. The prepared PDMS-SiO2@PU-Econea sponge shows not only super-hydrophobicity with a WCA of 154.5° but also excellent antifouling properties with more than 99% of inhibition to Escherichia coli after immersed in artificial seawater (salinity ≈35‰) for 50 days. It can absorb 133.9 times of trichloromethane than its own weight and still maintain 98.5% of absorption after 50 cycles. In addition, the PDMS-SiO2@PU-Econea sponge exhibits excellent continuous oil–water separation performance. The separation fluxes of n-hexane and dichloromethane are 151.0 and 136.3 L·h−1·g−1, respectively, and the oil–water separation efficiency is up to 99.9%, it can absorb 50 times of crude oil than its own weight in 75 s. Therefore, the antifouling and superhydrophobic PDMS-SiO2@PU-Econea sponge is a promising and applicable oil absorbent sponge for long-term oil/water separation and cleanup of oil spills in marine environment.