Thermal Transport in Graphene Oxide Films: Theoretical Analysis and Molecular Dynamics Simulation.

Yi Yang,Ning Wei,Rongxin Yan,Lina Wang,Yilun Liu,Yang Kang,Donghui Meng,Guohua Ren,Dan Zhong

doi:10.3390/nano10020285

Abstract

As a derivative material of graphene, graphene oxide films hold great promise in thermal management devices. Based on the theory of Fourier formula, we deduce the analytical formula of the thermal conductivity of graphene oxide films. The interlaminar thermal property of graphene oxide films is studied using molecular dynamics simulation. The effect of vacancy defect on the thermal conductance of the interface is considered. The interfacial heat transfer efficiency of graphene oxide films strengthens with the increasing ratio of the vacancy defect. Based on the theoretical model and simulation results, we put forward an optimization model of the graphene oxide film. The optimal structure has the minimum overlap length and the maximum thermal conductivity. An estimated optimal overlap length for the GO (graphene-oxide) films with degree of oxidation 10% and density of vacancy defect 2% is 0.33 μm. Our results can provide effective guidance to the rationally designed defective microstructures on engineering thermal transport processes.

Highlights

Graphene-oxide (GO) films show fascinating performance and have been widely applied in various fields [1,2,3,4,5,6]
The final overlap model of GO films with hydroxyl groups and vacancy defects is shown in molecular dynamics (MD) simulations are performed using the large-scale atomic/molecular massively parallel simulator
The coupling effect of the hydroxyl-group and vacancy defects on the out-of-plane thermal properties of GO is expressed by interfacial thermal conductance κ I

Summary

Introduction

Graphene-oxide (GO) films show fascinating performance and have been widely applied in various fields [1,2,3,4,5,6]. Of polymerThe thermal conductivity of GO films is much higher than that of polymer-based composites based composites [17,18], the current materials for dissipating heat in electronics [17,18],. This nanomaterial with highly single sheet in a layer-by-layer assembly approach This nanomaterial with κ anisotropic thermal conductivity (in-plane thermal conductivity i and out-of-plane thermal highly anisotropic conductivity (in-plane thermal conductivity κi and out-of-plane thermalof κ o ) thermal conductivity can be applied in thermal management of modern electronics. Study on the thermal conductivity of the overlap films structure at the layers.scale. The study on the thermal conductivity of the overlap GO films structure at the atomic is still atomic scale is stillwe lacking. Effect of of oxidation and monatomic vacancy defect on the out-of-plane thermal property is andegree optimized overlap length is discussed analytically.

Theoretical Analysis

Simulation

Equilibrium temperature profiles forforthe

Result and Discussion

Spatial distribution of heat flux arrows each atom under nonequilibrium

Conclusions