国内精品国产三级国产在线专_欧美日韩在线播放一区二区_成人xxxx视频_欧美激情视频一区_色女人综合av_久久久亚洲影院_久久久久久九九_成人免费网站在线_日韩美女毛茸茸_狠狠干一区二区

Alumina oxide was deposited in the straight nanosize pores of Anopore alumina membrane by the alternative introduction of trimethylaluminum (TMA) and water vapor to the membrane pores. The chemical vapor deposition (CVD) modification was conducted under two different schemes:? (1) cyclic CVD with residual pressure and (2) cyclic CVD with purge. The membranes were characterized by single gas helium permeance and water vapor/oxygen multiple gas permeation. Helium gas permeation results show that the modification by the residual pressure scheme caused greater reduction in the pore size than porosity, suggesting the deposition of alumina in a fractal structure in the Anopore membrane pores. Such a structure is caused by combined homogeneous and heterogeneous reactions taking place respectively on the pore wall and randomly in the pores. The membranes modified with CVD under the purge scheme exhibited greater reduction in porosity than the pore size, indicating that the alumina in the latter case was deposited on the pore wall in an atomic layer fashion. The structure in the latter case is caused by homogeneous reactions taking place on the pore wall. Membranes modified under the purge scheme exhibited improved water vapor/oxygen separation properties.