A solvent-template ethyl cellulose-polydimethylsiloxane crosslinking sponge for rapid and efficient oil adsorption

Lipophilic adsorbents for oil-water separation are usually synthesized using the template method, in which hydrophobic materials are coated on a ready-made sponge. Herein, a novel solvent-template technique is used to directly synthesize a hydrophobic sponge, by crosslinking polydimethylsiloxane (PDMS) with ethyl cellulose (EC) which plays a vital role in the formation of 3D porous structure. The as-prepared sponge has advantages of strong hydrophobility, high elasticity, as well as excellent adsorption performance. In addition, the sponge can be readily decorated by nano-coatings. After the sponge was simply dipped in nanosilica, the water contact angle increases from 139.2° to 144.5°, and the maximum adsorption capacity for chiroform rises from 25.6 g/g to 35.4 g/g. The adsorption equilibrium can be reached within 3 min, and, the sponge can be regenerated by squeezing, without any change in hydrophobility or evident decline in capacity. The simulation tests of emulsion separation and oil-spill cleanup demonstrate that the sponge has great potential in oil-water separation.