Fabrication of superhydrophobic polyurethane sponge for separation of oil from immiscible oil/water wastewater

Elimination of oil and organic pollutants from water has become an increasing global challenge due to the increment of industrial oily waste water as well as oil spill accidents. Conventional oil-removing approaches such as using various filters are not environmentally friendly and economical. Using absorption materials is considered as one of the most efficient ways to remove and recycle oils. Porous superhydrophobic materials have a great potential for separating oil from water due to high absorption capacity and high mechanical stability. In this study, fabrication of a superhydrophobic material that possesses good adhesion with hydrophobic coating is practiced using polyurethane. The surface of polyurethane porous sponge with three dimensional structure is coated through two-step coating procedure. First, the sponge surface is coated with poly(dopamine) polymer with the purpose of the modification of sponge skeleton so it adhere easily with silica layer that is the second coat on the surface of sponge acting as superhydrophobic layer. The results showed that the water contact angle of the prepared sponge is about 156.2±4.5 that proves superhydrophobicity character. The as-prepared hydrophobic sponge can adsorb a wide range of oils. According to the obtained results, this sponge can absorb oil 44-49 times of its original weight.

Keywords:

superhydrophobic , hydrophobic coating , contact angle