Rose Ian, Bezzu C Grazia, Carta Mariolino, Comesaña-Gándara Bibiana, Lasseuguette Elsa, Ferrari M Chiara, Bernardo Paola, Clarizia Gabriele, Fuoco Alessio, Jansen Johannes C, Hart Kyle E, Liyana-Arachchi Thilanga P, Colina Coray M, McKeown Neil B
EastChem, School of Chemistry, University of Edinburgh, David Brewster Road, Edinburgh EH9 3FJ, UK.
School of Engineering, University of Edinburgh, Robert Stevenson Road, Edinburgh EH9 3FB, UK.
Nat Mater. 2017 Sep;16(9):932-937. doi: 10.1038/nmat4939. Epub 2017 Jul 31.
The promise of ultrapermeable polymers, such as poly(trimethylsilylpropyne) (PTMSP), for reducing the size and increasing the efficiency of membranes for gas separations remains unfulfilled due to their poor selectivity. We report an ultrapermeable polymer of intrinsic microporosity (PIM-TMN-Trip) that is substantially more selective than PTMSP. From molecular simulations and experimental measurement we find that the inefficient packing of the two-dimensional (2D) chains of PIM-TMN-Trip generates a high concentration of both small (<0.7 nm) and large (0.7-1.0 nm) micropores, the former enhancing selectivity and the latter permeability. Gas permeability data for PIM-TMN-Trip surpass the 2008 Robeson upper bounds for O/N, H/N, CO/N, H/CH and CO/CH, with the potential for biogas purification and carbon capture demonstrated for relevant gas mixtures. Comparisons between PIM-TMN-Trip and structurally similar polymers with three-dimensional (3D) contorted chains confirm that its additional intrinsic microporosity is generated from the awkward packing of its 2D polymer chains in a 3D amorphous solid. This strategy of shape-directed packing of chains of microporous polymers may be applied to other rigid polymers for gas separations.
诸如聚（三甲基硅基丙炔）（PTMSP）之类的超渗透聚合物，有望减小气体分离膜的尺寸并提高其效率，但由于其选择性较差，这一期望仍未实现。我们报道了一种具有固有微孔性的超渗透聚合物（PIM-TMN-Trip），其选择性远高于PTMSP。通过分子模拟和实验测量，我们发现PIM-TMN-Trip二维（2D）链的低效堆积产生了高浓度的小（<0.7纳米）和大（0.7-1.0纳米）微孔，前者提高了选择性，后者提高了渗透性。PIM-TMN-Trip的气体渗透率数据超过了2008年罗布森对于O/N、H/N、CO/N、H/CH和CO/CH的上限，并且已证明其对相关气体混合物具有生物气净化和碳捕获的潜力。对PIM-TMN-Trip与具有三维（3D）扭曲链的结构相似聚合物的比较证实，其额外的固有微孔性源自其二维聚合物链在三维无定形固体中的笨拙堆积。这种微孔聚合物链的形状导向堆积策略可应用于其他用于气体分离的刚性聚合物。
