Coral stone-inspired superwetting membranes with anti-fouling and self-cleaning properties for highly efficient oil–water separation

다국어 초록 (Multilingual Abstract)

Nowadays, the use of separation membranes to deal with oil–water emulsions has gained popularity.
However, oil fouling of membrane surfaces during the separation of oil–water emulsion is still a significantchallenge. In this study, inspired by the biological coral stone structure, the gel layer was firmlyattached to the surface of membrane using a simple co-blending and cross-linking strategy. A superwettingmembrane (PVDF/CD-SA) with a coral stone structure was obtained. The PVDF/CD-SA membranehad a high permeate flux that was 4.2 times higher than that of the original membrane and a high separationefficiency of about 99.2 % for the separation of oil–water emulsion. Furthermore, the membranehad outstanding chemical stability. The fluxes of several different oil-in-water emulsions significantlyimproved, and the separation efficiencies were as high as 98 %. Moreover, the separation efficienciesand contact angles of the membrane remained unchanged after numerous cycles of use. The membraneexhibited excellent superhydrophilicity in air (instantaneous water wetting in air) and superoleophobicityunder water (underwater oil contact angle > 156). Most importantly, the oil was able to automaticallydetach from the surface of membrane, resulting in self-cleaning performance. Therefore, this PVDF/CD-SAmembrane eliminated the problem of oil adhesion, exhibiting excellent potential for practical applicationsin oil–water separation.