【摘要】 采用反扩散法制备介孔MCM-48分子筛膜.首先以CTAB和P123为双模板,以TEOS为硅源,合成了MCM-48晶种.采用热浸渍法在α-Al2O3载体上预涂MCM-48晶种层.MCM-48分子筛膜的制备采用反扩散法,即通过硅源(TEOS)和模板剂(CTAB)溶液分别配制,载体管内外分开装填的工艺制备介孔MCM-48膜.利用XRD、SEM及单组分气体渗透实验对制备的样品进行表征.XRD结果表明,所合成的MCM-48晶种具有良好的长程有序性及较高的规整度.从SEM照片看,合成的MCM-48粉体具有晶形,颗粒大小均匀.能够在大孔径的α-Al2O3管状载体上形成平整、致密的晶种层.MCM-48分子筛膜的SEM照片表明,膜层很薄,并且是连续致密的.室温下,制备的MCM-48分子筛膜的H2渗透率达到10-7 mol/(m2.s.Pa),压降为0.1MPa时MCM-48膜对H2/N2的分离系数达到3.0.更多还原

【Abstract】 Mesoporous silica MCM-48 membranes have been synthesized on a coarse-pore α-Al2O3 ceramic tube by counter-diffusion growth process(CDGP).First,MCM-48 seeds were prepared by hydrothermal synthesis using CTAB and P123 as co-templates,and TEOS as silica source.Then the seed aqueous solution was prepared and coated on outer surface of the preheated supports by dip-coating technique to form a continuous seed layer.And then MCM-48 membrane was prepared using the CDGP method.Different from the conventional synthesis methods by which the silica source and the template agent were mixed together to form the synthesis solution,the CDGP method introduced silica source and template agent from the opposite direction of a support wall,resulting in good membrane structures and properties.The seeds and MCM-48 membrane were characterized by small-angle X-ray diffraction,SEM measurement and gas permeation tests.XRD patterns showed the seeds had a typical MCM-48 XRD patterns.SEM analysis revealed that the MCM-48 membranes were dense,continuous and without obvious defects,indicating good permeation property.At room temperature,the separation selectivity of H2/N2 was up to 3.0 under 0.1 MPa pressure drop.更多还原