Chemical Engineering Research Center, School of Chemical Engineering and Technology, Tianjin University, Tianjin 30072, PR China.
Tianjin Key Laboratory of Membrane Science and Desalination Technology, State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 30072, PR China.
ACS Appl Mater Interfaces. 2015 Jul 22;7(28):15481-93. doi: 10.1021/acsami.5b03786. Epub 2015 Jul 9.
It is desirable to develop high-performance composite membranes for efficient CO2 separation in CO2 capture process. Introduction of a highly permeable polydimethylsiloxane (PDMS) intermediate layer between a selective layer and a porous support has been considered as a simple but efficient way to enhance gas permeance while maintaining high gas selectivity, because the introduced intermediate layer could benefit the formation of an ultrathin defect-free selective layer owing to the circumvention of pore penetration phenomenon. However, the selection of selective layer materials is unfavorably restricted because of the low surface energy of PDMS. Various highly hydrophilic membrane materials such as amino group-rich polyvinylamine (PVAm), a representative facilitated transport membrane material for CO2 separation, could not be facilely coated over the surface of the hydrophobic PDMS intermediate layer uniformly. Inspired by the hydrophilic nature and strong adhesive ability of polydopamine (PDA), PDA was therefore selected as a versatile molecular bridge between hydrophobic PDMS and hydrophilic PVAm. The PDA coating endows a highly compatible interface between both components with a large surface energy difference via multiple-site cooperative interactions. The resulting multilayer composite membrane with a thin facilitated transport PVAm selective layer exhibits a notably enhanced CO2 permeance (1887 GPU) combined with a slightly improved CO2/N2 selectivity (83), as well as superior structural stability. Similarly, the multilayer composite membrane with a hydrophilic CO2-philic Pebax 1657 selective layer was also developed for enhanced CO2 separation performance.
开发用于 CO2 捕集过程中高效 CO2 分离的高性能复合膜是可取的。在选择性层和多孔支撑体之间引入高渗透性的聚二甲基硅氧烷(PDMS)中间层被认为是一种简单但有效的方法,可以在保持高气选择性的同时提高气体透过率,因为引入的中间层可以由于避免了孔穿透现象,有利于形成超薄无缺陷的选择性层。然而,由于 PDMS 的低表面能,对选择性层材料的选择不利地受到限制。各种高亲水性膜材料,如富含氨基的聚乙烯亚胺(PVAm),作为 CO2 分离的代表性促进传递膜材料,不能均匀地涂覆在疏水性 PDMS 中间层的表面上。受聚多巴胺(PDA)的亲水性和强粘附能力的启发,因此选择 PDA 作为 PDMS 和 PVAm 之间的通用分子桥。PDA 涂层通过多位置协同相互作用在具有较大表面能差异的两个组件之间赋予高度相容的界面。具有薄的促进传递 PVAm 选择性层的多层复合膜表现出显著增强的 CO2 透过率(1887 GPU),同时略微提高了 CO2/N2 选择性(83),以及优异的结构稳定性。同样,还开发了具有亲 CO2 的亲水性 Pebax 1657 选择性层的多层复合膜,以提高 CO2 分离性能。