Thermal conductivity of PDMS chains and GNPs/PDMS composites: a molecular dynamics study

摘要

Molecular dynamics (MD) simulations are considered to be an effective way to analyze the thermal behavior ofnanocomposites for various components. In this study, we investigate the thermal conductivities of PDMS chains as wellas the GNPs/PDMS composites by non-equilibrium molecular dynamics (NEMD) simulations. Firstly, the thermalproperties of PDMS chains are calculated by taking account of the effects of temperature, length and number of chains.Then, a series of GNPs/PDMS composite models which have various PDMS chains are parallel to the surface of GNPs areproposed, and their thermal conductivities are studied in terms of the numbers and position of the chains. The simulationresults show that the thermal conductivity of the PDMS chains linearly increases with their lengths and numbers. However,the temperature has minimum influence on thermal conductivity. The proposed GNPs/PDMS composite model withaligned GNPs/PDMS, which could avoid disordered and phonon scattering at interfaces has a huge increase in thermalconductivity compared to the PDMS chains. A case study shows that the position of the PDMS chains has effect on thethermal conductivity of GNPs/PDMS composites, and the PDMS chains in one side of GNPs has higher thermalconductivity than the PDMS chains in two sides of GNPs.