摘要
采用原料配比SiO2∶Al2O3∶Na2O∶H2O=2∶1∶8.9∶700制备了粒径为6μm的NaA沸石晶种.利用二次生长法在微孔α-Al2O3载体管外表面制备NaA型分子筛膜,通过SEM和XRD对制备的分子筛膜进行了结构表征,并对其气体渗透性能进行了测试.结果表明,重复合成3次后,在3μm孔径载体表面形成了一层致密、连续的沸石晶体层,沸石膜厚约20μm;N2的渗透率为5.8×10-5 mol/(m2.s.Pa),氧氮分离系数为1.3左右,大于相应的努森扩散系数0.94,说明制备的分子筛膜有一定的筛分作用.
NaA zeolite seeds with 6 μm in size are synthesized by using the ratio of raw materials SiO2∶A12O3∶Na2O∶H2O = 2∶1∶8.9∶700.NaA zeolite membranes are synthesized by first forming a seeding layer on the support via negative pressure adsorption method,followed by secondary crystallization method.The membrane is characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）,and its gas permeate performance is tested.The results show that after several hydrothermal synthesis steps,a dense intergrown zeolite crystallayer about 20 μm in thickness is formed on the outer surface of 3 μm pore size tubular and there is no apparent crack between them.N2 permeance of as-synthesized NaA membrane is 5.8 × 10-5mol/（m2·s·Pa）,the ideal selectivity of O2/N2 is 1.3,which is over the value of Knudsen 0.94.NaA membrane of preparation has certain molecular sieving property.
出处
《天津工业大学学报》
CAS
北大核心
2011年第2期65-68,共4页
Journal of Tiangong University
基金
军事医学科学院卫生装备研究所科技发展基金(2009001)
关键词
无机膜
NAA型分子筛膜
水热合成
二次生长
氧氮分离
inorganic membrane
NaA zeolite membrane
hydrothermal synthesis
secondary growth
separation of O2 /N2
