FUNCTIONALIZATION OF CARRIER TRANSPORT MEMBRANES BY THE CONTROL OF MICROSTRUCTURE

1. 在促进输运理论的基础上，成功地推导了CO_2与胺反应的反应速率常数和平衡常数对CO_2渗透率的影响。化学平衡常数适中的胺有利于获得较高的CO_2渗透率。通过促进输运模型考察了微孔支撑膜特性的影响。研究发现，在不带电荷的情况下，支架的厚度、孔隙度和弯曲度是影响输送速率的重要因素。采用低温等离子体将丙烯酸（AA）接枝到微孔聚乙烯（PE）膜上，制备了离子交换膜（PE-g-AA）。用单质子化乙二胺（EDAH^+）浸渍PE-G-AA膜（PE-G-AA - eda）对CO_2对CH_4有很高的选择性。这是由于PE-g-AA膜的高含水量导致膜中载流子的高迁移率，也是由于AA接枝层的高离子位（COO-）浓度导致载流子浓度高。该膜是稳定的，因为载体（EDAH^+）被静电力保持在膜中。考虑离子交换膜中载体的扩散系数，用该模型模拟了CO_2的促进输运速率。采用等离子体接枝聚合法制备了磺酸基微孔离子交换膜。结果表明，所制备的膜以硝酸银为载体，作为C2H4转运的载体是非常有效的。通过DSC测量和时差法测量CO_2的扩散率和溶解度，可以阐明（EDAH^+）浸渍PVA凝胶膜的交联率、含水量和未冻水分数对CO_2迁移的影响。

1. The effects of reaction rate constant and equilibrium constant of the reaction between CO_2 and amine on the permeability of CO_2 were successfully formulated on the basis of facilitated transport theory. An amine with moderate chemical equilibrium constant was found to be favorable to obtain high CO_2 permeability.2. The effect of the characteristics of microporous support membrane was examined by the facilitated transport model. It was found that the thickness, porosity and tortuosity of the support are the important factors which influence the facilitated transport rate if the support has no electric charge.3. Ion exchange membranes (PE-g-AA membrane) were prepared by grafting acrylic acid (AA) onto microporous polyethylene (PE) membranes using low temperature plasma. Facilitated transport membranes (PE-g-AA-EDA) prepared by impregnating the PE-G-AA membranes with monoprotonated ethylenediamine (EDAH^+) showed very high selectivity of CO_2 over CH_4. This was due to high mobility of carrier in the membrane resulting from high water content of PE-g-AA membrane and also due to high carrier concentration resulting from high ion site (COO-) concentration of AA graft-layr. The membrane was stable because the carrier (EDAH^+) was held in the membrane by the electrostatic force. The facilitated transport rate of CO_2 was simulated by the proposed model by considering the diffusivity of the carrier in the ion exchange membrane.4. Microporous ion exchange membranes having sulfonic acid groups were prepared by plasma graft polymerization method. The prepared membranes were found to be very effective as the supports of facilitated transport of C2H4 using silver nitrate as the carrier.5. The effects of cross-linking ratio, water content and fraction of unfrozen water in PVA gel membranes impregnated with (EDAH^+) on the facilitated transport of CO_2 could be elucidated by the DSC measurement and the diffusivity and solubility of CO_2 measured by time-lag method.