Synthesis of NaA Zeolite Membranes with High Water Flux on Macroporous Si 3 N 4

Abstract

LTA zeolite membranes have been extensively investigated for dehydration applications. However, preparing high flux NaA zeolite membranes remains a challenge. Porous Si3N4 which combines high porosity with excellent mechanical strength, presents a promising support material for developing such high-performance membranes. In this work, high flux NaA membranes achieved controlled fabrication on macroporous Si3N4 supports via a secondary growth method. A simple and efficient double layer seed-coating method was employed under variable temperature. Sufficient crystallization time promotes synthesis gel penetration into the support-seed interface, enabling anisotropic crystal growth to form mechanical interlocking between NaA membrane and β-Si3N4 grains. The optimal membrane showed the flux up to 5.76 kg m-2 h-1 and separation factor of 8432 for the dehydration of 90 wt.% ethanol/water at 70°C.