D_4等离子体聚合物复合膜的制备、形成过程及其氧氮分离性

<正> 将高分子膜用于气体分离已越来越受到人们的重视.在特定条件下,用等离子体聚合可形成高分子超薄膜,它有高度交联结构,表面平整、致密、无针孔.因此,将它用于气体分离是有希望的.本工作用八甲基环四硅氧烷(简称D_4)作单体,进行等离子体聚合,沉积在聚丙烯多孔底膜上,得到D_4等离子体聚合物复合膜.研究表明,该膜有较好的气体透过性能,其氧气透过速率Jo_2为0.5—2×10~(-5)cm~3(STP)/cm~2·sec·cmHg,氧氮分离系数。αo/N为3.3—3.8,远远高于用经典方法制得的聚有机硅氧烷膜的αo/N2.0.

THE PREPARATION AND THE FORMATION PROCESS OF D4 PLASMA POLYMER COMPOSITE MEMBRANES AND THEIR OXYGEN-NITROGEN SEPARATION PROPERTY

The cyclooctamethyltetrasiloxane (D4) plasma composited membranes were prepared by D4 plasma polymer deposited on the porous polypropylene substrate under the conditions of frequency 13.56 MH power 50-100 W, pressure 0.05-0.2 mbar, low-electrode temperature 20±2℃, deposite time 7-60 min. The oxygen permeation rate Jo2 andd oxygen-nitrogen separation coeff. αo/N of the obtained membranes are 0.5-2×10-5 cm3(STP)/cm2·sec·cmHg and 3.3-3.8, respectively. The formation process of the composited membranes was studied by means of SEM together with the gas peameation properties of the membranes obtained at different reaction time.