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研究了微孔ＳｉＯ２膜的气体渗透性能．气体渗透数据表明，由于微孔ＳｉＯ２膜存在着一定的孔径分布，其渗透机理比较复杂．当膜的孔径大于并接近分子的动力学直径时，其渗透由择形扩散控制；而当膜的孔径大于而不接近分子的动力学直径时，对于非凝聚的小分子气体其渗透受努森扩散控制；对于可凝性气体其渗透将受多层扩散和毛细管凝聚的控制．单组份正／异丁烷气体在２５℃、压差为０．０６ＭＰａ时的理想分离系数为１．８；１∶１的正／异丁烷混合气的分离系数为８．４．
The gas permeability of microporous SiO2 membrane was studied. Gas permeation data show that due to the existence of a certain pore size distribution of microporous SiO2 membrane, the infiltration mechanism is more complicated. When the pore size of the membrane is larger than and close to the kinetic diameter of the molecule, its permeation is controlled by shape-selective diffusion; and when the pore size of the membrane is larger than but not close to the kinetic diameter of the molecule, its permeation to the non-condensed small molecule gas is controlled by Knudsen Diffusion control; for condensable gases, their infiltration will be controlled by multilayer diffusion and capillary condensation. The ideal separation factor of single-component n-butane gas at 25 ℃ and pressure difference of 0.06MPa is 1.8. The separation coefficient of n-butane and n-butane mixture at 1: 1 is 8.4.