Pore size engineering of SiC ceramic membrane with pre-ceramic polymer for high retention performance and corrosion resistance

Silicon carbide (SiC) ceramic membranes are highly valued in separation technologies for their outstanding thermal stability, chemical resistance, and durability. However, achieving precise pore size control remains a major challenge. In this work, we introduce polycarbosilane (PCS) as a pre-ceramic precursor and employ a simple dip coating-crosslinking-pyrolysis route to finely engineer SiC membrane pores. We systematically investigate the effects of substrate humidity, PCS coating concentration, oxidative crosslinking, and pyrolysis temperature on membrane morphology, pore size distribution, permeate flux, and nanoparticle rejection. Under optimized conditions (5 wt % PCS and 1000 °C pyrolysis), the mean pore diameter decreases by 20 %, and crosslinking enhances particle rejection by 31.8 %. The modified membranes also exhibit exceptional corrosion resistance, with less than 0.25 % mass loss after 30 days in pH 1 and pH 13 solutions. This approach establishes a clear humidity-loading-pore relationship and offers a scalable, controllable strategy for ceramic membrane pore engineering, paving the way for applications under harsh water treatment and chemical separation conditions.