Effects of the Tube Diameter on the Mechanical Properties of Black Phosphorene Nanotubes

We use molecular dynamics finite element method with Stillinger-Weber potential to study the effects of the tube diameter on the mechanical properties of black phosphorene nanotubes (BPNT). Various armchair and zigzag BPNTs with a wide range of diameters from ~12 through ~34 A are considered. The effects of the tube diameter on the mechanical properties of zigzag tubes are more significant than those of the armchair ones. When increasing the diameter in the studied range, the Young’s modulus and fracture stress increase about 10% and 8.6%; and 109% and 214% for armchair and zigzag tubes, respectively; whereas, the fracture strains decrease very slightly (~3%) for the armchair tubes and increase up to 113% for the zigzag ones. When the diameter of BPNT is sufficiently large, its mechanical properties approach to those of the black phosphorene sheet.