Molecular Dynamics Study On Thermal Transport Properties Of Graphene With Fractal Defects

The change of the under-atmosphere pad surface caused by industrialization and urbanization,the density of urban buildings and the concentration of waste heat emissions such as industrial and civil air conditioning have led to the increasingly prominent phenomenon of heat pollution such as the hot island effect of urban areas,which has caused great distress to the human living environment and the earth's ecological environment.With the sharp decline in the price of graphene,it is possible to use graphene to build new green building materials.Inspired by the research of electronic devices,this paper introduces fractal defects into graphene to design new energy control materials based on the characteristics of fractal structure.In this paper,the thermal transport properties of fractal defect graphene is studied fby molecular dynamics firstly,and the results show that the larger the fractal level of fractal graphene,the lower the thermal conductivity in plane.Its thermal conductivitiy goes down from 164.40 W/m K to 19.60 W/m K,because the fractal defect increases the thermal flow path,reduces the actual thermal transport area and enhances the phonon scattering of edge.Further,after coupling fractal graphene with the perfect graphene substrate,the fractal graphene heterostructures van der Waal was constructed,and the molecular dynamics calculation results show that in the range of 200 K to 400 K,interfacial thermal conductances are greater than the reverse interfacial thermal conductance,which has a certain thermal rectification capacity.And,in the temperature range of 200 K to 400 K,its interfacial thermal conductance went from 11.36 MW/m~2K to14.38 MW/m~2K,while the reverse interface thermal resistance reduced from 8.37MW/m~2K to 10.95 MW/m~2K.Furthermore,the thermal conductivity of fractal graphene in the perfect graphene van der Waals force is increased by up to 80%.Fractal graphene and fractal graphene heterostructure are expected to provide useful reference for the design of new green building materials based on graphene integration or the thermal element design of new very large-scale integrated electronic devices.