Preparation of functional separation membrane by polymerization using atmospheric pressure glow descharge plasma

常压辉光放电（APG）等离子体工艺在设备成本、处理大基底和连续操作等方面具有优势。我们制备了APG等离子体反应器，并利用APG等离子体演示了等离子体处理、等离子体聚合和等离子体接枝聚合技术。用He对聚二甲基硅氧烷膜表面进行APG等离子体修饰，研究了膜对CO_2的渗透性和CO_2对CH_4的选择性。与低压等离子体处理情况一样，随着APG等离子体处理时间的增加，CO_2的渗透率呈单调下降趋势。等离子体处理大大提高了CO_2的选择性，远远超过了未处理的聚二甲基硅氧烷膜的选择性，其选择性与膜表面的结构有很好的相关性，而C-OH等极性基团的存在可能增加了CO_2与膜表面的亲合力。采用APG等离子体法制备了聚二甲基硅氧烷薄膜。无论等离子体是否暴露于C_2H_4单体，聚乙烯薄膜都发生了聚合。因此，聚乙烯薄膜被认为是由等离子体引发聚合沉积的。采用APG等离子体接枝聚合技术，在微孔聚乙烯基体上包覆接枝丙烯酸，制备了阳离子交换膜。该方法是APG等离子体所特有的。将接枝膜应用于以EDAH^+为CO_2载体的助输膜上。该载体在离子交换膜中的静电力作用下固定化。获得了高的CO_2渗透率和选择性。

The atmospheric pressure glow discharge (APG) plasma process would be advantageous ad regards, the cost of apparatus, treatment of large substrates and the continuous operation. We prepared the APG plasma reactor and demonstrated plasma treatment, plasma polymerization and plasma graft polymerization techniques using APG plasma.The surface of poly (dimethysiloxane) membrane was modified by the APG plasma treatment using He, and the CO_2 permeability and the selsctivity of CO_2 over CH_4 were investigated in detail. Permeance of CO_2 decreased monotomously with the increase of the APG plasma treatment time as in the case of the low pressure plasma treatment. CO_2 selectivity was much improved by the plasma treatment, and went well beyond the value of the untreated poly (dimethylsiloxane) membrane The selectivity could be well correlated with the structure of membrane surface and the affinity between CO_2 and the membrane surface was considered to increase by the existence of the polar groups such as C-OH.Polyethylene film was prepared by the APG plasma method onto the poly (dimethylsiloxane) membrane. Irrespective of the plasma exposing to C_2H_4 monomer, polyethylene film was polymerized. Therefore, polythylene film was considered to be deposited by the plasma-initiated polymerization.The cation-exchange membrane were prepared by grafting acrylic acid coated on the substrates such as microporous polythylene by the use of APG plasma graft polymerization technique. The gtafting method was peculiar to APG plasma. The grafted membrane was applied to the facilitated transport membrane using EDAH^+ as carrier of CO_2. The carrier was immobilized by the electrostatic force in the ion exchange membranes. The high CO_2 permeance and selectivity were obtained.