A robust air superhydrophilic/superoleophobic diatomite porous ceramic for high-performance continuous separation of oil-in-water emulsion

Three-dimensional (3D) porous architecture has attracted considerable attention in remediation of oil/water emulsion. In present work, an air superhydrophilic/superoleophobic diatomite porous ceramic (AS-DC) was prepared, using SiO2 whiskers modified diatomite ceramic as the substrate and FS-50 as the modifier. The interconnected SiO2 whiskers intertwined on the skeleton of ceramic block forming a 3D network structure, which not only improved the wettability of AS-DC, but also reinforced its mechanical property (about 2.5 MPa of compressive strength). The as-prepared AS-DC with intrinsically superoleophobicity (154 degrees) and superhydrophilicity (0 degrees) exhibited an underwater oil contact angle of 161 degrees, suggesting a multifunctional separation capability. By simply assembling AS-DC with pipes and a pump, it could not only separate the surfactant stabilized oil-in-water emulsion in a permeation flux as high as 107.8 kg min(-1) m(-2) with a selectivity of > 95%, but also collect the clean water from the floating oil/water mixture in a flux of 197.4 kg min(-1) m(-2) and a selectivity of similar to 99%. In addition, the AS-DC was resistant to the salt/acid/alkaline corrosion and temperature fluctuation. The mechanical/chemical firmness of AS-DC renders it tremendous potential as a robust 3D architecture in real application for purification of oil/water mixture.

Automated summary

In this study, an air superhydrophilic/superoleophobic diatomite porous ceramic (AS-DC) with excellent mechanical properties and multifunctional separation capabilities was prepared. By simple assembly, AS-DC can efficiently separate oil-in-water emulsion and collect clean water. Furthermore, AS-DC exhibits resistance to corrosion and temperature fluctuation, indicating its great potential for various applications.