Facile preparation of superhydrophobic/superoleophilic diatomite porous ceramics for efficient oil-water separation

Abstract

In this work, a superhydrophobic diatomite porous ceramic was successfully prepared via a straightforward impregnation and heat-treatment way using isobutylene-maleic anhydride copolymer and SiO2 nanoparticles (NPs) as co-modifier. Due to the removal of the hydroxyl group after 1 h heating at 573 K in a 5 % H2/Ar atmosphere, the amide group in the original isobutylene-maleic anhydride copolymer was transformed to imide group, endowing the porous ceramics with excellent hydrophobic property. Furthermore, the addition of SiO2 NPs which enhanced the surface roughness resulted in the superhydrophobic properties of the final products. The continuous oil-water separation test of as-prepared superhydrophobic diatomite porous ceramics exhibited an initial separation flux of over 205.5 kg·min−1·m−2 with a separation selectivity of over 93 % for various oil-water mixtures. Moreover, their oil-adsorption tests demonstrated an 1.6–57 times adsorption capacity as high as these of other traditional inorganic sorbent materials.