Li Yifan, Wang Shaofei, Wu Hong, Guo Ruili, Liu Ye, Jiang Zhongyi, Tian Zhizhang, Zhang Peng, Cao Xingzhong, Wang Baoyi
Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University , Tianjin 300072, China.
ACS Appl Mater Interfaces. 2014 May 14;6(9):6654-63. doi: 10.1021/am500356g. Epub 2014 Apr 23.
A novel strategy to design a high-performance composite membrane for CO2 capture via coating a thin layer of water-swellable polymers (WSPs) onto a porous support with enriched CO2-philic groups is demonstrated in this study. First, by employing a versatile platform technique combining non-solvent-induced phase separation and surface segregation, porous support membranes with abundant CO2-philic ethylene oxide (EO) groups at the surface are successfully prepared. Second, a thin selective layer composed of Pebax MH 1657 is deposited onto the support membranes via dip coating. Because of the water-swellable characteristic of Pebax and the enriched EO groups at the interface, the composite membranes exhibit high CO2 permeance above 1000 GPU with CO2/N2 selectivity above 40 at a humidified state (25 °C and 3 bar). By tuning the content of the PEO segment at the interface, the composite membranes can show either high CO2 permeance up to 2420 GPU with moderate selectivity of 46.0 or high selectivity up to 109.6 with fairly good CO2 permeance of 1275 GPU. Moreover, enrichment of the PEO segment at the interface significantly improves interfacial adhesion, as revealed by the T-peel test and positron annihilation spectroscopy measurement. In this way, the feasibility of designing WSP-based composite membranes by enriching CO2-philic groups at the interface is validated. We hope our findings may pave a generic way to fabricate high-performance composite membranes for CO2 capture using cost-effective materials and facile methods.
本研究展示了一种新颖的策略，即通过在具有富集亲二氧化碳基团的多孔载体上涂覆一层薄的水膨胀性聚合物（WSP）来设计用于二氧化碳捕获的高性能复合膜。首先，通过采用非溶剂诱导相分离和表面偏析相结合的通用平台技术，成功制备了表面具有大量亲二氧化碳环氧乙烷（EO）基团的多孔支撑膜。其次，通过浸涂将由Pebax MH 1657组成的薄选择层沉积在支撑膜上。由于Pebax的水膨胀特性以及界面处富集的EO基团，复合膜在加湿状态（25°C和3 bar）下表现出高于1000 GPU的高二氧化碳渗透率以及高于40的二氧化碳/氮气选择性。通过调整界面处PEO链段的含量，复合膜可以表现出高达2420 GPU的高二氧化碳渗透率以及46.0的中等选择性，或者高达109.6的高选择性以及1275 GPU的相当好的二氧化碳渗透率。此外，T型剥离试验和正电子湮没光谱测量表明，界面处PEO链段的富集显著改善了界面粘附力。通过这种方式，验证了通过在界面处富集亲二氧化碳基团来设计基于WSP的复合膜的可行性。我们希望我们的发现可以为使用经济高效的材料和简便方法制造用于二氧化碳捕获的高性能复合膜开辟一条通用途径。
