Xu Xiaozhi, Wang Jiajie, Zhou Awu, Dong Siyuan, Shi Kaiqiang, Li Biao, Han Jingbin, O'Hare Dermot
State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, People's Republic of China.
Beijing Key Laboratory for Green Catalysis and Separation Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing, People's Republic of China.
Nat Commun. 2021 May 24;12(1):3069. doi: 10.1038/s41467-021-23121-z.
Membrane-based gas separation exhibits many advantages over other conventional techniques; however, the construction of membranes with simultaneous high selectivity and permeability remains a major challenge. Herein, (LDH/FAS)-PDMS hybrid membranes, containing two-dimensional sub-nanometre channels were fabricated via self-assembly of unilamellar layered double hydroxide (LDH) nanosheets and formamidine sulfinic acid (FAS), followed by spray-coating with a poly(dimethylsiloxane) (PDMS) layer. A CO transmission rate for (LDH/FAS)-PDMS of 7748 GPU together with CO selectivity factors (SF) for SF(CO/H), SF(CO/N) and SF(CO/CH) mixtures as high as 43, 86 and 62 respectively are observed. The CO permselectivity outperforms most reported systems and is higher than the Robeson or Freeman upper bound limits. These (LDH/FAS)-PDMS membranes are both thermally and mechanically robust maintaining their highly selective CO separation performance during long-term operational testing. We believe this highly-efficient CO separation performance is based on the synergy of enhanced solubility, diffusivity and chemical affinity for CO in the sub-nanometre channels.
基于膜的气体分离相对于其他传统技术具有许多优势；然而，构建同时具有高选择性和高渗透性的膜仍然是一项重大挑战。在此，通过单层层状双氢氧化物（LDH）纳米片与甲脒亚磺酸（FAS）的自组装，随后用聚二甲基硅氧烷（PDMS）层进行喷涂，制备了包含二维亚纳米通道的（LDH/FAS）-PDMS混合膜。观察到（LDH/FAS）-PDMS的CO传输速率为7748 GPU，以及对于CO/H、CO/N和CO/CH混合物的CO选择性因子（SF）分别高达43、86和62。CO渗透选择性优于大多数已报道的系统，并且高于罗伯逊或弗里曼上限。这些（LDH/FAS）-PDMS膜在热和机械方面都很坚固，在长期运行测试中保持其高选择性的CO分离性能。我们认为这种高效的CO分离性能基于亚纳米通道中对CO增强的溶解性、扩散性和化学亲和力的协同作用。
