The fabrication of robust and highly efficient oil–water separation filters via the high temperature sintering of silica micropower

Abstract

Superhydrophobic materials have been shown to have many attractive properties, however, their functionality can easily be lost due to the failure of the air layer. For long lasting air layer retention, dedicated mechanisms to maintain this layer and/or reintroduce air into the system are essential. Any air reintroduction control would allow for increased air lifetime but would require a porous material that allows air flow to be effective. Here, we prepared highly porous superhydrophobic materials, fabricated through facile sintering of silica nanoparticles followed by chemical functionalisation. Sintering temperatures were varied to maximise the material's strength and water contact angles, with angles of up to 153° achieved. Furthermore, the porous properties were demonstrated through oil/water separation experiments, where separation efficiencies of up to 98% were recorded.