열화학적 IS 공정에서 요오드화수소의 분해에 적용하기 위하여 화학증착법(CVD)으로 제조된 silica 막의 안정성을 HI-$H_2O$ 기상 혼합물에서 평가하였다. Si 원천으로 tetraethoxysilane을 사용하여 서로 다른 CVD 온도로 기공크기가 100 nm인 $alpha$-alumina를 처리하였다. CVD온도는 $700^{circ}C$, $650^{circ}C$, $600^{circ}C$이었다. $600^{circ}C$에서 수행한 단일 성분의 투과 실험에서 측정한 막의 $H_2$/$N_2$ 선택도는 CVD 온도 $700^{circ}C$의 M1 막은 43.2, $650^{circ}C$의 M2 막은 12.6, $600^{circ}C$의 M3 막은 8.7을 나타내었다. HI-$H_2O$ 기상 혼합물에서 안정성 실험은 $450^{circ}C$에서 수행하였는데, CVD 온도 $650^{circ}C$에서 처리된 막이 다른 온도에서 처리된 막보다 더 안정성이 더 좋은 결과를 얻었다.
The stability of the prepared silica membrane by chemical vapor deposition (CVD) method in the HI-$H_2O$ gaseous mixture was evaluated aiming at the application for hydrogen iodide decomposition in the thermochemical IS process. Porous $alpha$-alumina having pore size of 100 nm was modified by the different CVD temperature using tetraethoxysilane as the Si source. The CVD temperature was $700^{circ}C$, $650^{circ}C$, and $600^{circ}C$. The $H_2$/H$_2$ selectivities of the modified membranes which were measured by single-component permeation experiment showed 43.2, 12.6, and 8.7 at $600^{circ}C$ for the M1 (CVD temperature was $700^{circ}C$), M2 (CVD temperature was $650^{circ}C$) and M3 membranes (CVD temperature was $600^{circ}C$), respectively. Stability experiment in the HI-$H_2O$ gaseous mixture was carried out at $450^{circ}C$. The prepared silica membrane at $600^{circ}C$ of CVD temperature was more stable than that at the other CVD temperature.
