ZSM-5分子筛膜/SiSiC复合材料的制备与表征

Preparation and Characterization of ZSM-5 Films/SiSiC Ceramics Composites

以生物形态多孔木材SiSiC陶瓷为载体,采用二次生长法在其孔道内壁合成了薄且连续、致密的ZSM-5分子筛膜。采用SEM、EDX、BET对多孔ZSM-5/SiSiC复合材料进行了表征。研究结果表明,采用静电组装技术,在木材陶瓷孔道内表面形成了单层、致密的分子筛晶种层。在100℃水热合成48h可在SiSiC陶瓷孔道内壁形成平均厚度为120nm的ZSM-5分子筛膜,且很好地复制了陶瓷载体的孔道结构,表现为连续致密的管状结构。制得的分子筛陶瓷复合材料的BET比表面积、微孔体积、ZSM-5分子筛负载量分别为17.8m2/g、0.00413cm3/g、2.36%。延长水热合成时间并不能增加膜的厚度,但ZSM-5分子筛膜表面的n(SiO2)∶n(Al2O3)会降低。

ZSM-5 films are successfully synthesized within the channels of biomorphic porous SiSiC ceramics by secondary growth method. The ZSM-5 films/SiSiC ceramics composites are characterized by SEM, EDX and BET. The experiment results show that a dense and monolayer seeds layer is formed by using electrostatic method. After secondary growth at 100~C for 48h, a continuous, homogeneous zeolite film with an average thickness of 120nm is formed within the channel system of SiSiC ceramics. The zeolite films copies the channel structure of ceramics with typical cylinder shape. The specific surface areas, microporous volume and corresponding zeolite loading of the composites are 17.8m2/g, 0. 00413cm3/g and 2. 36% respectively. The thickness of zeolite film does not increase by increasing the synthesis time, whereas the molar ratio of SiO2 and Al2O3 decreases.