| Summary: | 碩士 === 國立臺灣大學 === 化學工程學研究所 === 90 === The objective of this study is to reduce pore size of tubular alumina membrane under 2nm using TEOS via chemical vapor deposition (CVD) route. Consequently, we can promote the applications and increase the value of tubular alumina membrane from Chung-Shan Institute of Science and Technology (CSIST).
The system assembly、gas permeability、CVD reaction, and character -rization of SiO2 membrane are included in this work. Tubular alumina membranes from CSIST consist of two kind of pore sizes, 0.02μm and 0.006μm. The permeabilities of pore size 0.02μm clean membrane is 50-90 for He, and 30-60 for N2. As to clean membrane of pore size 0.006μm, He and N2 permeabilities are 20-50 and 10-30 respectively. After modified by CVD, the permeability of all tube membrane decreases with deposition time. The He/N2 selectivity of 0.006μm clean membrane can be enhanced to 17, compared with 1.96 before CVD. Based on Knudsen diffusion, H2/N2 selectivity may achieve up to 24.4. The thickness and microstructure of SiO2 layer are observed by scanning electron microscopy (SEM). Nitrogen adsorption and mercury intrusion estimated the pore size distribution and porosity. Chemical state and quantity analysis of SiO2 and Al2O3 was recognized through XPS and EDX.
|
|---|
