PEI-NaA/α-Al_2O_3复合支撑分子筛膜的微波水热合成

Microwave Synthesis of Polyetherimide-NaA/α-Al_2O_3 Supported Zeolite Membrane

采用微波水热合成法在聚醚酰亚胺(PEI)-NaA分子筛/α-Al2O3复合载体表面合成了具有高选择性的致密NaA型分子筛膜,重点考察了微波辐射时间对成膜的影响。采用X射线衍射图谱(XRD)和扫描电子显微镜(SEM)对NaA型分子筛膜进行了表征。XRD结果表明,复合载体表面生成的膜中只有NaA分子筛的晶相;SEM结果表明,复合载体基膜表面覆盖了一层致密连续的NaA型分子筛膜。合成的NaA型分子筛膜在不同质量分数乙醇中的渗透汽化性能结果表明,渗透通量随乙醇质量分数增大而减小,分离因子则反之,当乙醇质量分数为95%时,渗透通量仅0.05 kg/(m2.h),而分离因子高达13 000。

The high-performance NaA zeolite membrane was synthesized on polyetherimide（PEI）-NaA zeolite/α-Al2O3 composite supports by the microwave heating method.The influence of microwave heating time on membrane synthesis was mainly investigated.The as-synthesized NaA zeolite membranes were characterized by XRD and SEM.XRD results show that only NaA zeolite emerges on the composite support surface.The SEM results show the composite support surface is fully covered by uniform and compact NaA zeolite membrane.The pervaporation properties of the as-synthesized membrane were evaluated by the dehydration of alcohol/water mixture.It was found that the flux decreased with the increment of the alcohol amount in the feed and the separation factors were the contrary.The pervaporation results present that the separation factors were as high as 13 000 at m（CH3CH2OH）/m（H2O）=95∶5.On the other hand,the fluxes were only 0.05 kg/（m2·h）.