Center for Synthetic Soft Materials, Key Laboratory of, Functional Polymer Materials of Ministry of Education and Institute of, Polymer Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, P.R. China.
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, P.R. China.
Chemistry. 2019 Oct 17;25(58):13396-13401. doi: 10.1002/chem.201902875. Epub 2019 Sep 13.
Organic polymers and inorganic clusters belong to two different disciplines and have completely different properties and structures. When a cluster is attached to the backbone of a polymer as a pendant, the resultant hybrid polymers (polyclusters) exhibit unique behaviours totally different from those of conventional polymers owing to the nanoscale size of the cluster and its particular interactions. Herein, the aggregation of a poly(polyoxometalate)-a polynorbornene backbone with inorganic polyoxometalate cluster pendants-upon addition of a non-solvent to its dilute solution is reported. A three-dimensional network of tangled and snake-like nanothreads was observed. Direct visualisation of individual nanoscale clusters enabled identification of single chains within the nanothreads. These observations suggest that during the process of aggregation, the hybrid polymer forms curved or extended chains as a consequence of an armouring effect in which the collapsed cluster pendants wrap around the backbone. The collapse occurs because they become less soluble in the solvent/non-solvent mixture. The extended chains then become entwined and form nanoropes consisting of multiple chains wound around each other. This study provides a deeper understanding of the nature of polyclusters and should also prove useful for their future development and application.
有机聚合物和无机团簇属于两个不同的学科，具有完全不同的性质和结构。当团簇作为侧基连接到聚合物主链上时，由于团簇的纳米尺度及其特殊相互作用，所得的杂化聚合物（多团簇）表现出与传统聚合物完全不同的独特行为。在此，报道了一种聚（多金属氧酸盐）-聚降冰片烯主链与无机多金属氧酸盐团簇侧基的聚集，在向其稀溶液中加入非溶剂时发生。观察到三维纠缠和蛇形纳米线网络。通过对单个纳米级团簇的直接可视化，可以识别纳米线内的单链。这些观察结果表明，在聚集过程中，由于装甲效应，即塌陷的团簇侧基围绕主链包裹，使得杂化聚合物形成弯曲或伸展的链。塌陷发生是因为它们在溶剂/非溶剂混合物中的溶解度降低。然后，伸展的链相互交织并形成由多个链缠绕在一起的纳米绳。这项研究提供了对多团簇性质的更深入了解，也应该对它们的未来发展和应用有用。
