Fondazione Bruno Kessler, Via Sommarive 18, Povo, 38123 Trento, Italy.
European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*), Fondazione Bruno Kessler, Strada delle Tabarelle 286, Villazzano, 38123 Trento, Italy.
Int J Mol Sci. 2023 Jan 27;24(3):2473. doi: 10.3390/ijms24032473.
The manufacturing of high-modulus, high-strength fibers is of paramount importance for real-world, high-end applications. In this respect, carbon nanotubes represent the ideal candidates for realizing such fibers. However, their remarkable mechanical performance is difficult to bring up to the macroscale, due to the low load transfer within the fiber. A strategy to increase such load transfer is the introduction of chemical linkers connecting the units, which can be obtained, for example, using carbon ion-beam irradiation. In this work, we investigate, via molecular dynamics simulations, the mechanical properties of twisted nanotube bundles in which the linkers are composed of interstitial single carbon atoms. We find a significant interplay between the twist and the percentage of linkers. Finally, we evaluate the suitability of two different force fields for the description of these systems: the dihedral-angle-corrected registry-dependent potential, which we couple for non-bonded interaction with either the AIREBO potential or the screened potential ReboScr2. We show that both of these potentials show some shortcomings in the investigation of the mechanical properties of bundles with carbon linkers.
制造高模量、高强度纤维对于现实世界中的高端应用至关重要。在这方面，碳纳米管是实现此类纤维的理想候选材料。然而，由于纤维内的负载传递较低，它们显著的机械性能很难在宏观尺度上体现出来。一种增加这种负载传递的策略是引入连接单元的化学连接物，例如可以使用碳离子束辐照来获得。在这项工作中，我们通过分子动力学模拟研究了由间隙单碳原子组成的连接物的扭转纳米管束的机械性能。我们发现扭转和连接物百分比之间存在显著的相互作用。最后，我们评估了两种不同力场用于描述这些体系的适宜性：双角修正的位相关势能，我们将其与 AIREBO 势能或屏蔽势能 ReboScr2 耦合用于非键相互作用。我们表明，这两种势能在研究具有碳连接物的束的机械性能时都存在一些缺点。
