比利时鲁汶大学Feyter, Steven De观察了二维动态共价聚合物的聚合。相关研究成果发表在2022年3月30日出版的国际知名学术期刊《自然》。
结晶二维（2D）聚合物的质量与难以捉摸的聚合和结晶过程密切相关。在（亚）分子水平上理解这些过程的机理对于提高预测合成和调整材料性能，以应用于催化和（光）电子学等领域至关重要。
研究人员利用原位扫描隧道显微镜对模型硼氧烷2D动态共价聚合物进行了表征，以实时和在环境条件下揭示成核-延伸过程的定性和定量细节。连续数据分析可以观察非晶态到晶态的转变、晶核随时间的演化、“非经典”晶化途径的存在，重要的是，可以通过实验精确地确定基本的晶化参数，包括临界晶核尺寸、成核速率和生长速率。
原子计算机模型对实验数据进行了进一步的合理化，这些模型共同提供了动态表面聚合过程的详细图片。此外，研究人员还展示了异常晶粒生长对2D晶体生长的影响。该发现为利用异常晶粒生长（金属和陶瓷体系中的典型现象）将多晶结构转化为有机和二维材料体系中的单晶提供了支持。
附：英文原文
Title: Observing polymerization in 2D dynamic covalent polymers
Author: Zhan, Gaolei, Cai, Zhen-Feng, Strutyski, Karol, Yu, Lihua, Herrmann, Niklas, Martnez-Abada, Marta, Melle-Franco, Manuel, Mateo-Alonso, Aurelio, Feyter, Steven De
Issue&Volume: 2022-03-30
Abstract: The quality of crystalline two-dimensional (2D) polymers1,2,3,4,5,6 is intimately related to the elusive polymerization and crystallization processes. Understanding the mechanism of such processes at the (sub)molecular level is crucial to improve predictive synthesis and to tailor material properties for applications in catalysis7,8,9,10 and (opto)electronics11,12, among others13,14,15,16,17,18. We characterize a model boroxine 2D dynamic covalent polymer, by using in situ scanning tunnelling microscopy, to unveil both qualitative and quantitative details of the nucleation–elongation processes in real time and under ambient conditions. Sequential data analysis enables observation of the amorphous-to-crystalline transition, the time-dependent evolution of nuclei, the existence of ‘non-classical’ crystallization pathways and, importantly, the experimental determination of essential crystallization parameters with excellent accuracy, including critical nucleus size, nucleation rate and growth rate. The experimental data have been further rationalized by atomistic computer models, which, taken together, provide a detailed picture of the dynamic on-surface polymerization process. Furthermore, we show how 2D crystal growth can be affected by abnormal grain growth. This finding provides support for the use of abnormal grain growth (a typical phenomenon in metallic and ceramic systems) to convert a polycrystalline structure into a single crystal in organic and 2D material systems.
DOI: 10.1038/s41586-022-04409-6
Source: https://www.nature.com/articles/s41586-022-04409-6