本文要点：
- 生产高质量的二维（2D）共价有机框架（COFs）对于工业应用至关重要。然而，对于当前的合成技术来说，这仍然具有很大的挑战性。深入了解分子间相互作用、反应温度和低聚物对于促进高结晶COF薄膜的生长至关重要。
- 在这里，分子动力学模拟被用来探索石墨烯上单体组装的2D COFs的生长。结果表明，链增长反应主导了COF表面增长，范德华力相互作用在通过单体预组织提高结晶度方面是重要的。
- 此外，适当调节反应温度提高了COF结晶度并使无定形低聚物的影响最小化。另外，COF和石墨烯基底之间的界面强度表明粘附力与COF的结晶度成比例。
- 这项工作揭示了COFs在表面成核和生长的机理，并为制备高质量的2D聚合物基晶体纳米材料提供了理论指导。
Figure 1. Schematic view of the organic monomer polymerization models. (a) A schematic for the fabrication processes of COF. (b) Differential charge density distribution of PDA and TAPB. (c) A molecular model of 80 TAPB and 120 PDA on monolayer graphene. (d) Two-step polycondensation of COFTAPB-PDA during a running MD simulation.
Figure 2. Growth process of COF at 393 K. (a) The evolution of PE of the COF during whole polymerization process. (b) Snapshots for the whole polymerization process of COF. TAPB and PDA are colored cyan and magenta, respectively. (c) Polymerization ratio ξ versus reaction time for five random repeat tests at the same reaction temperature (393 K). (d) Comparison of the linear density of the initial and final structures along the x-direction. (e-f) Comparison of the radial distribution function (RDF) of the center-of-mass of TAPB and PDA molecules.
Figure 3. Nucleation mechanisms and crystallization mechanisms of COF at different T.
Figure 4. Effect of oligomers on COF growth.
Figure 5. Peeling mechanism of 2D COF film on graphene surface. (a) Schematic showing the peeling process of COF from graphene. (b) SMD-derived peeling force in COF systems at three T along zigzag edge. (c) Peeling snapshot of COF film on the graphene at 393 K.
https://pubs.acs.org/doi/abs/10.1021/acsnano.3c11787
本文来自COF催化在线，本文观点不代表石墨烯网立场，转载请联系原作者。
