A theoretical insight into the mechanical properties and phonon thermal conductivity of biphenylene network structure

The numerous applications of carbon-based nanomaterials clearly demonstrate the importance of polymorphism in carbon. Two-dimensional biphenylene is a recently-synthesized sp²-hybridized allotrope of carbon atoms that needs further investigation. Thermal conductivity and mechanical strength are two important features which determine the life span and the performance of two-dimentional biphenylene under operating conditions. Sevaral parametrs such as temeperature, temperature gradient, strain rate, length, would affect the mechanical characteristic and thermal conductivity. Therefore, it is imperative to look into how the aforementioned parameters affect thermo-mechanical performance in order to have a greater understanding of the two-dimensional biphenylene's competency under working conditions. This study aims to investigate the mechanical and phonon thermal conductivity of biphenylene nanosheet (BPNS) concerning some effective factors like strain rates, structure's lengths, and temperatures by means of molecular dynamics (MD) simulation. Regarding the obtained results of mechanical properties of BPNS, it was revealed that the Young's modulus, failure stress, and failure strain were decreased by elevating the temperature due to the rise in interatomic distances and decrement of binding energy. Moreover, better mechanical properties were generally observed along the zigzag direction. Mechanical features increased and decreased gradually by increasing strain rates and sample’ length, respectively. Infinite thermal conductivity of BPNS were obtained 146.41 W.m^-1k⁻¹ and 133.51 W.m^-1k⁻¹ in zigzag and armchair orientation, respectively. The variations of temperature difference between two hot and cold bathes had negligible effect on phonon thermal conductivity. However, the increment of temperature and strain caused the reduction and promotion in phonon thermal conductivity of BPNS, respectively. The relevance of this research lies in its capacity to analyze distinct BPNS behaviors, which has significant potential for use in sensors, reinforcements, and electrodes.