不锈钢支撑体表面NaA分子筛膜的合成与表征

Synthesis and Characterization of NaA Zeolite Membranes on the Stainless Steel Support

利用二次生长法在不锈钢片式支撑体上合成出Na A分子筛膜。采用XRD、FE-SEM和渗透汽化分离技术对所合成的膜进行了系统表征。研究结果表明所合成的膜具有(200)面取向性,并且合成时间和合成次数对膜的取向性以及分离性能有重要影响。在2次3.5h的合成条件下,所制备的膜具有较优的取向性和分离性能,其XRD图谱上NaA分子筛(200)面与(220)面的峰强比值达到22,远高于无取向NaA分子筛膜的峰强比值。该膜在343 K下分离含水量5 wt.%的乙醇溶液时,其水/乙醇分离因子和渗透通量分别为1290和1.12kg·h^(-1)·m^(-2)。

NaA zeolite membranes were synthesized on the stainless steel supports by second growth method. The as-synthesized membranes were characterized by XRD and FE-SEM and pervaporation experiments. The results showed that the as-synthesized membranes exibited oriented with the crystal face of(200) parallel on substrate surface. The influence of synthetic time and number on the orientation and peformance of zeolite membranes were investigated. High quality membranes with orientation were obtained at the synthesis time of 3.5 twice. The intensity ratio of 22 for XRD peaks(200) over peak(220) on the oriented membranes was obviously lager than random NaA zeolite membranes. The oriented membranes showed the flux of 1.12 kg·m^(-2)·h^(-1) and separation factor of 1290 for dehydration of 95︰5(wt.%) ethanol/water mixtures at 343 K.