Pure-SiC ceramic membrane for ultrafiltration: Morphology, pore characteristics and separation performances

Silicon carbide (SiC) ceramic membranes have gained increasing attention due to their excellent chemical and thermal stability serving in harsh conditions. However, the use of SiC ceramic membrane is limited in micro-filtration fields because of the micro-scale pores in the selective layer. Here, a pure-SiC ultrafiltration (UF) membrane was prepared by dip-coating and recrystallization sintering using fine SiC particles of 100 nm and 50 nm in sizes. EDS and XRD analysis confirmed that the membrane was composed of pure-SiC phase, which endowed the UF membrane with strongly chemical resistance. Because of the refinement in particles, the average pore sizes of the ceramic membrane made of 100 nm and 50 nm particles corresponded to 82 nm and 58 nm, respectively. Due to the refinement in pore size, the oil flux increased from 69.50 L/(m2·h) to 99.01 L/(m2·h) and the oil rejection exceeded 98.8 % for the 50 nm membrane.