Preparation of Zeolite T Membranes with Different Ratios of Water and SiO_2

In the present work, effect of water content in the synthesis solution on the membrane performance and structure was studied. It was found that water content will affect the compactness and thickness of the functional layer. It also affected the crystal size and morphology. When the n(H_2O)/ n(SiO_2) was 20, the membrane showed rod zeolite T crystals. More water will cause thinner zeolite membrane and loose structure with some defects. When n(H_2O)/ n(SiO_2) reached 30, dense zeolite T membrane was formed with rod crystals. The obtained T-type zeolite membranes were used to separate isopropanol/water mixed solution containing 90 wt.% isopropanol at 348 K, the permeation flux was 3.34 kg·m^-2·h^-1 and the separation coefficient was 2536.