不对称醋酸纤维素膜气体渗透行为探讨

The Invesgaittion on Gas Permeation Behaviors of Asymmetric Cellulose Acetate Membrane

本文利用扫描电子显擞镜观察了不对称醋酸纤维膜素的形态,其构造由四层组成:表面致密层,较小微孔层,指孔层,较大微孔层.表面致密层存在有缺陷。通过计算,对不同气体(N_2,CO_2,O_2,H_2,CH_4)透过该膜的模型作了探讨,主要考虑了孔流机理(诺森流,粘性流和滑流)及表面流的影响,认为表面致密层对该膜的气体渗透性起着决定性的作用。气体以诺森流和粘性流的迭加形式进行渗透,同时存在吸附表面流。理论计算值和实验值基本相符。

The morphorlogy of asymmetric cellul4ose acetate membrane was described by using scanningelectron microscope in this paper.It includs four layers:Surface dense layer,Smaller-micropore layer.Fingerpore layer and Larger-micropore layer.Some defects exist in the Surface dense layer.Thepereation model passing the membrane for different gas (N_2,CO_2,O_2,H_2,CH_4)was studied by calcula-tion and experimental method.The Pore flow mechanism (Knudsen flow,Viscous flow,and Slio flow)and the effect of Surface Adsorption flow were mainly considered.The gas permeation behaviors de-pend on the surface dense layer,the permeation model is mainly considered as a pile of Knudsen andViscous flow,the Surface Adsorption flow exists simultaneously.The theoretical calculation valuesare in good agreement to the experimental values.