Facile preparation of superhydrophobic and superoleophilic porous polymer membranes for oil/water separation from a polyarylester polydimethylsiloxane block copolymer

To fabricate superhydrophobic membranes for oil/water separation, a mesh serving as a support is usually required for improving mechanical properties and rendering a micro-scale porous structure. Herein, we develop a simple spraying-coating process for producing superhydrophobic and superoleophilic porous polymer membranes without meshes as supports from a fluorinated polyarylester polydimethylsiloxane block copolymer (PAR-b-PDMS). It is exciting that the surface morphology of the PAR-b-PDMS membranes can be controlled by the copolymer solution concentration. The PAR-b-PDMS membranes are endowed with promising superhydrophobicity and superoleophilicity, displaying excellent oil affinity and low water adhesion behaviors. Significantly, the PAR-b-PDMS membranes exhibit fast and efficient separation for oil/water mixtures with separation efficiency as high as 99 %. And after 50 cycles of oil/water separation, the as-prepared membranes can still maintain stable superhydrophobicity and high separation efficiency, indicating good recyclability and durability. Moreover, the fabrication approach presented here can be easily scaled up for producing polymer membranes on a large scale, which makes it very promising for practical oil/water separation.