Synthesis of hierarchically porous silica film with controllable surface wettability

A kind of water-oil separation material was fabricated by depositing the mesoporous microspheres (MS) on filter paper. MS had been prepared via surfactanttemplate method and modified by octyltriethoxysilane. The diameter of microspheres was in the range of 200-800 nm. There were uniform mesopores in the microspheres, and the surface area of microspheres was more than 1,000 m(2) g(-1). The thin film, showing both hydrophobicity and lipophilicity, had a high contact angle for water (greater than 130 degrees) and a low one for n-hexane (about 0 degrees). Meanwhile, the film presented excellent separating efficiency between water and oil, which could reach 98.8 %. Good selectivity and simple preparation procedure might lead the material to be highly valuable on water-oil separation.