ETS-4分子筛膜的制备

Preparation of ETS-4 zeolite membranes

采用晶种法在多孔管状莫来石支撑体外表面水热合成ETS-4分子筛膜.研究合成条件,包括晶种、合成液碱度以及合成时间对ETS-4晶体生长和膜形成的影响.采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对ETS-4分子筛及分子筛膜进行了表征.通过75℃、质量分数为10%的水/乙醇混合物对膜的渗透汽化分离性能进行检测.实验结果表明,在碱性介质中,Al从支撑体析出,导致在支撑体孔中形成方沸石,影响了膜的渗透汽化分离性能.

ETS-4 zeolite membranes were hydrothermally prepared on the outer-surface of porous mullite tubular supports by a seeding method. The effect of synthesis conditions including seeds, alkalinity of synthetic solutions, and synthesis time on ETS-4 crystal growth and membrane formation was studied. The as-synthesized ETS4 zeolite and membranes were characterized by XRD and SEM. The membrane pervaporation （PV） separation property for a 10% water feed concentration of a water/ethanol mixture at 75℃ was tested. The results showed that the leach of alumina from the support in the alkali media resulted in formation of analcime-type zeolite in the pore of the support, thus strongly affecting the performance of membrane PV.