Abstract
Oily wastewater and oil spills pose a threat to the environment and human health, and porous sponge materials are highly desired for oil/water separation. Herein, we design a new superhydrophobic/superoleophilic TiO(2)-decorated polyvinyl alcohol (PVA) sponge material for efficient oil/water separation. The TiO(2)-PVA sponge is obtained by firmly anchoring TiO(2) nanoparticles onto the skeleton surface of pristine PVA sponge via the cross-linking reactions between TiO(2) nanoparticles and H(3)BO(3) and KH550, followed by the chemical modification of 1H,1H,2H,2H-perfluorodecyltrichlorosilane. The as-prepared TiO(2)-PVA sponge shows a high water contact angle of 157° (a sliding angle of 5.5°) and an oil contact angle of ∼0°, showing excellent superhydrophobicity and superoleophilicity. The TiO(2)-PVA sponge exhibits excellent chemical stability, thermal stability, and mechanical durability in terms of immersing it in the corrosive solutions and solvents, boiling it in water, and the sandpaper abrasion test. Moreover, the as-prepared TiO(2)-PVA sponge possesses excellent absorption capacity of oils or organic solvents ranging from 4.3 to 13.6 times its own weight. More importantly, the as-prepared TiO(2)-PVA sponge can separate carbon tetrachloride from the oil-water mixture with a separation efficiency of 97.8% with the aid of gravity and maintains a separation efficiency of 96.5% even after 15 cyclic oil/water separation processes. Therefore, the rationally designed superhydrophobic/superoleophilic TiO(2)-PVA sponge shows great potential in practical applications of dealing with oily wastewater and oil spills.