Mechanical property assessment of black phosphorene nanotube using molecular dynamics simulation

The study attempts to investigate the mechanical properties of single-walled black phosphorene nanotubes (SW-BPNTs) at atmospheric pressure through molecular dynamics (MD) calculation incorporating with the Nose-Hoover Langevin (NHL) thermostat. Their dependences on size, chirality and temperature are also addressed. Two typical cross-sectional area definitions, i.e., hollow tube and equivalent solid cylinder, are used in the estimate of the mechanical properties. The predicted results are compared with each other and also with the literature data. The calculation results reveal that the Young's modulus, shear modulus, specific heat and CTE of both armchair and zigzag SW-BPNTs would increase with the tube length and diameter, and additionally, the Young's modulus and shear modulus appear to change significantly with chiral angle. It is also found that the Young's modulus calculated using the hollow tube assumption would increase with the tube diameter while there is an opposite trend for the equivalent solid cylinder assumption. According to the equivalent solid cylinder assumption, the nanoscale SW-BPNTs are not a very stiff material. Moreover, the specific heat and linear coefficient of thermal expansion (CTE) of SW-BPNTs, irrespective of chirality and size, increase with temperature at low temperature and tend to converge to a certain value when temperature is larger than 600 K. Besides, the calculated specific heat of SW-BPNTs closely follows the Debye T-3 law. (C) 2017 Elsevier B.V. All rights reserved.