陶瓷中空纤维内表面动态水热合成NaA分子筛膜及其表征

采用动态水热法在氧化铝陶瓷中空纤维内表面原位合成了NaA分子筛膜。利用X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)表征了分子筛膜的物相及微观形貌,通过渗透汽化测试考察了膜的乙醇/水分离性能,研究了合成工艺参数对成膜过程及膜质量的影响。结果表明,动态下合成的分子筛膜,晶体交联紧致,膜层薄且连续性好,厚度约4μm;提高动态速度有利于降低载体内外合成液的温差和浓度差,缩短晶化时间。在温度343K下,分离质量分数90%的乙醇/水体系,膜的渗透通量和分离因子可达1.03kg/(m2·h)和3 781,对乙醇/水表现出良好的分离效果和可重复性。

Synthesis and Characterization of NaA Zeolite Membranes on the Inner Side of Hollow Fiber Support by a Dynamic Hydrothermal Process

NaA zeolite membranes coated on the inner surface of hollow fiber support were synthesized directly in dynamic state by in-situ hydrothermal synthesis method.The phase,morphology and alcohol/water separation were characterized by X-ray diffraction (XRD),field emission scanning electron microscopy (FE-SEM) and pervaporization,respectively.The influences of the dynamic state hydrothermal condition on the quality of the as-synthesized membranes were investigated.The results show that NaA zeolite membranes fabricated in the dynamic state hydrothermal condition exhibit an excellent continuity,intersecting twin-crystal structure without obvious ecological gravity deposition crystal.The membranes thickness is about 4 μm.The improvement of rota tion speed is beneficial to decrease the difference of temperature and concentration in both sides of carrier wall,and reduce crystalliza tion time.In addition,the as-synthesized membrane exhibit 90％ ethanol/water pervaporation performance and technology repeatability at 343 K.The permeation flux and the separation factor of the membranes are over 1.03 kg/(m2 · h) and 3 781,respectively.