Molecular Dynamics Simulation of Thermal Boundary Conductance Between Carbon Nanotubes and SiO2

TL;DR

This study uses molecular dynamics simulations to analyze how heat transfers between carbon nanotubes and SiO2, revealing dependencies on interaction strength, diameter, and temperature, and aligning with experimental data.

Contribution

It provides a detailed quantitative analysis of thermal boundary conductance between CNTs and SiO2, highlighting the scaling laws and relaxation times involved.

Findings

Thermal boundary conductance scales with Van der Waals strength, diameter, and temperature.

Relaxation time of CNT on SiO2 is approximately 85 ps, independent of diameter.

Results align with experimental variations due to surface and temperature differences.

Abstract

We investigate thermal energy coupling between carbon nanotubes (CNTs) and SiO2 with non-equilibrium molecular dynamics simulations. The thermal boundary conductance (g) per unit CNT length is found to scale proportionally with the strength of the Van der Waals interaction (~X), with CNT diameter (~D), and as a weak power law of temperature (~T^1/3 between 200-600 K). The thermal relaxation time of a single CNT on SiO2 is independent of diameter, tau ~ 85 ps. With the standard set of parameters g ~ 0.1 W/m/K for a 1.7 nm diameter CNT at room temperature. Our results are comparable to, and explain the range of experimental values for CNT-SiO2 thermal coupling from variations in diameter, temperature, or details of the surface interaction strength.