Liu Zhongyun, Qiu Wulin, Quan Wenying, Koros William J
School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
Nat Mater. 2023 Jan;22(1):109-116. doi: 10.1038/s41563-022-01426-8. Epub 2022 Dec 12.
Carbon molecular sieve (CMS) membranes with precise molecular discrimination ability and facile scalability are attractive next-generation membranes for large-scale, energy-efficient gas separations. Here, structurally engineered CMS membranes derived from a tailor-made cross-linkable copolyimide with kinked structure are reported. We demonstrate that combining two features, kinked backbones and cross-linkable backbones, to engineer polyimide precursors while controlling pyrolysis conditions allows the creation of CMS membranes with improved gas separation performance. Our results indicate that the CMS membranes provide a versatile platform for a broad spectrum of challenging gas separations. The gas transport properties of the resulting CMS membranes are interpreted in terms of a model reflecting both molecular sieving Langmuir domains and a disordered continuous phase, thereby providing insight into structure evolution from the cross-linkable polyimide precursor to a final CMS membrane. With this understanding of CMS membrane structure and separation performance, these systems are promising for environmentally friendly gas separations.
具有精确分子识别能力且易于扩展的碳分子筛（CMS）膜是用于大规模、节能气体分离的有吸引力的下一代膜。在此，报道了由具有扭结结构的定制可交联共聚酰亚胺衍生的结构工程化CMS膜。我们证明，在控制热解条件的同时，结合扭结主链和可交联主链这两个特征来设计聚酰亚胺前体，可以制备出具有改善的气体分离性能的CMS膜。我们的结果表明，CMS膜为广泛的具有挑战性的气体分离提供了一个通用平台。所得CMS膜的气体传输特性根据反映分子筛分朗缪尔域和无序连续相的模型进行解释，从而深入了解从可交联聚酰亚胺前体到最终CMS膜的结构演变。基于对CMS膜结构和分离性能的这种理解，这些系统有望用于环境友好型气体分离。
