Carbon nanofiber based superhydrophobic foam composite for high performance oil/water separation

Oil spill has now been a serious environmental issue, threatening the aquatic ecosystems and even human living environment. It is still challenging to develop absorbents for efficient oil/water emulsion separation and clean-up of viscous crude oil. Here, we propose a facile method to fabricate flexible and superhydrophobic foam com-posites for high efficiency oil/water separation under different complex environment. Carbon nanofibers (CNFs) with a hollow structure are decorated uniformly onto the skeleton of the polydimethylsiloxane (PDMS) foam with a strong interfacial adhesion. CNFs could not only enhance the surface roughness and thus the hydrophobicity but also be served as numerous capillary tubes, improving the oil adsorption and oil/water separation performance. More importantly, the CNFs network with a strong light absorption endows the foam with superior photo-thermal conversion capability. The obtained foam composite possesses excellent corrosion resistance and can adsorb various kinds of oil with different densities. The foam composite is able to separate the oil from the emulsion with a relatively high separation efficiency. The material surface temperature is able to quickly increase under the light irradiation, which can significantly reduce the oil viscosity and hence achieve the rapid clean-up of the crude oil floating on water surface.

Automated summary

The study presents a method to fabricate flexible and superhydrophobic foam composites for efficient oil/water separation by decorating carbon nanofibers (CNFs) with a hollow structure uniformly onto the polydimethylsiloxane (PDMS) foam skeleton. The CNFs not only enhance the surface roughness and hydrophobicity, but also act as numerous capillary tubes, improving oil adsorption and oil/water separation performance. The CNFs network with strong light absorption enables the foam material to have superior photo-thermal conversion capability, excellent corrosion resistance, and the ability to adsorb various kinds of oil with different densities, resulting in high oil/water separation efficiency.