Preparation of superhydrophilic-underwater superoleophobic SiO2@SiC ultrafiltration ceramic membrane for high-efficient oil-water separation

Membrane fouling resulting from oil-water separation is an urgent issue that must be addressed. In this study, we employed a simple dip-coating and calcination technique to load SiO2 nanoparticles onto the SiC ceramic membrane, successfully have prepared superhydrophilic-underwater superoleophobic SiO2@SiC anti-fouling ultrafiltration ceramic membrane. An optimal ratio of SiO2 nanoparticles was determined, at which the prepared SiO2@SiC ceramic membrane exhibited a nominal pore size of 86 nm and a pure water permeation flux of 2816.47 L center dot m-2 center dot h-1 , which was close to that of the original SiC ceramic membrane, resulting from both superhydrophilicity and underwater superoleophobicity of the SiO2@SiC ceramic membrane which was beneficial for improving the permeation flux and offset the flux reduction caused by the decrease in pore size. Compared to original SiC ceramic membrane, SiO2@SiC ceramic membrane demonstrated an increased removal efficiency for various types of oils (by 5 %-14 %). During 15 cycle tests, SiO2@SiC ceramic membrane still maintained excellent antifouling performance and stable permeation flux and oil removal efficiency due to the formation of cake filtration mechanism. This study provides an important reference for the preparation of ultrafiltration ceramic membrane that achieve high permeation flux and oil removal efficiency simultaneously.