Dynamic Regulation Of Thermal Conductivity Based On Folded Graphene

Nano-scale heat transport has a completely different mechanism from macroscopic scale.In recent years,heat management and transformation in nanostructures has become a research hotspot in the field of heat transfer.In order to regulate thermal transport(phonon transport)at the nanoscale,researchers have drawn inspiration from electronics to design various phonon thermal devices corresponding to electronic devices,including thermal diodes,triodes,and thermal memories.The phonon thermal device corresponding to the adjustable resistor is an adjustable thermal resistor that can be used to dynamically regulate thermal conductivity.In this paper,the non-equilibrium molecular dynamics simulation method is used to study the dynamic regulation of thermal conductivity based on bending graphene.The morphology of the graphene is changed by continuous stretching,and the change law of the thermal conductivity of graphene is studied to achieve the purpose of dynamically adjusting the thermal conductivity.The calculation results show that the thermal conductivity of the single-layer bent graphene undergoes a rapid decline after the slow decline.This is because the van der Waals force between the graphene planes in the system affects the bending deformation of the structure.The degree,which in turn leads to a change in thermal conductivity.At 300 K,the single-layer bent graphene with a length of 8.6 nm has a thermal conductivity control range of up to 60%.At the same time,the single-layer bent graphene also showed significant temperature dependence and size dependence under tensile action.The structural morphology and thermal conductivity of the graphene bent during the stretching and compression process can be well matched,which indicates that the flexural graphene has reversibility for the dynamic regulation of thermal conductivity.Moreover,the theoretical mechanism that causes the change of thermal conductivity is studied by calculating the potential energy of the system and the density of phonon states.Based on the study of single-layer bent graphene,this paper also attempts to study the use of multilayer bending graphene to regulate thermal conductivity.Compared with single-layered graphene,multi-layered graphene is difficult to maintain good morphology during stretching,and it is more difficult to regulate thermal conductivity.Therefore,the method of applying a van der Waals flat wall is employed to maintain the structural morphology of the multilayered graphene.Based on the practical application,this research work is based on the dynamic regulation of thermal conductivity of bent graphene.The research results provide a new idea for designing thermal devices such as adjustable thermal resistors,and provide some guidance for the thermal regulation of two-dimensional nanomaterials.