Machine Learning-Assisted High-Throughput Molecular Dynamics Simulation of High-Mechanical Performance Carbon Nanotube Structure

• Published in: Nanomaterials (Basel, Switzerland) Vol. 10; no. 12; p. 2459
• Main Authors: Xiang, Yi, Shimoyama, Koji, Shirasu, Keiichi, Yamamoto, Go
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 09.12.2020; MDPI
• Subjects: Algorithms; Carbon; carbon nanotube; Carbon nanotubes; Chirality; Crosslinking; Density; Frenkel-pair crosslink; Learning algorithms; Machine learning; Mechanical properties; Modulus of elasticity; Molecular dynamics; molecular dynamics simulations; Nanotechnology; Nanotubes; Self organizing maps; Simulation; Tensile strength; Tensile tests; molecular dynamics simulations; Frenkel-pair crosslink; carbon nanotube; machine learning; mechanical properties
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano10122459

Carbon nanotubes (CNTs) are novel materials with extraordinary mechanical properties. To gain insight on the design of high-mechanical-performance CNT-reinforced composites, the optimal structure of CNTs with high nominal tensile strength was determined in this study, where the nominal values correspond to the cross-sectional area of the entire specimen, including the hollow core. By using machine learning-assisted high-throughput molecular dynamics (HTMD) simulation, the relationship among the following structural parameters/properties was investigated: diameter, number of walls, chirality, and crosslink density. A database, comprising the various tensile test simulation results, was analyzed using a self-organizing map (SOM). It was observed that the influence of crosslink density on the nominal tensile strength tends to gradually decrease from the outside to the inside; generally, the crosslink density between the outermost wall and its adjacent wall is highly significant. In particular, based on our calculation conditions, five-walled, armchair-type CNTs with an outer diameter of 43.39 Å and crosslink densities (between the inner wall and outer wall) of 1.38 ± 1.16%, 1.13 ± 0.69%, 1.54 ± 0.57%, and 1.36 ± 0.35% were believed to be the optimal structure, with the nominal tensile strength and nominal Young's modulus reaching approximately 58-64 GPa and 677-698 GPa.