Formation of surface skin layer of asymmetric polyimide membranes and their gas transport properties
Formation of surface skin layer of asymmetric polyimide membranes and their gas transport properties
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DOI：
10.1016/s0376-7388(97)00198-1
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发表时间：
1997-12-24
影响因子：
9.5
通讯作者：
Nagaoka, S
中科院分区：
文献类型：
--
作者：
Kawakami, H;Mikawa, M;Nagaoka, S
本文介绍了不对称6FDA-APPS膜的制备及其气体传输特性。表观表观表层厚度强烈依赖于蒸发时间，这对形成高气体渗透率的非对称膜至关重要。用原子力显微镜(AFM)测定了膜的表面形貌。AFM显微照片分析表明，膜的表面粗糙度参数随着表观厚度的减小而增大。在35℃和760厘米汞压力下，测量了CO2、O-2、N-2和CH4在不对称膜中的渗透率和选择性。当膜透氧率为5.6×10~(-5)cm(-5)/cm(2)S时，膜对(O-2/N~-2)和(CO_2/CH_4)的选择性分别为6.1和39。不对称膜的气体选择性等于或甚至高于致密膜的气体选择性。(C)1997年爱思唯尔科学公司。
The fabrication and gas-transport properties of asymmetric 6FDA-APPS membranes have been described in this study. The apparent skin-layer thickness strongly depended on the evaporation time, which was of the utmost importance for the formation of an asymmetric membrane with high gas permeance. Surface morphology of the membrane has been determined by atomic force microscopy (AFM). The surface roughness parameters of the membranes analyzed from AFM micrographs increased with a decrease in the apparent skin-layer thickness. Permeance and selectivity of CO2, O-2, N-2, and CH4 for the asymmetric membranes at 35 degrees C and at pressures up to 760 cmHg have been measured. The selectivities for (O-2/N-2) and (CO2/CH4) in the membrane with a skin layer of 34 nm were 6.1 at an O-2 permeance of 5.6 x 10(-5) cm(3)(STP)/cm(2) s cmHg and 39 at a CO2 permeance of 2.7 x 10(-4) cm(3)(STP)/cm(2) s cmHg, respectively, without the necessity of an additional coating process. The asymmetric membrane exhibited gas selectivities equal to or even higher than those determined for the dense membrane. (C) 1997 Elsevier Science B.V.