Thermal conductivity temperature dependence of water confined in nanoporous silicon

Abstract

Abstract Recently, it has been shown that high density nanoconfined water was the reason of the important enhancement of the effective thermal conductivity up to a factor of 50% of a nanoporous silicon filled with water. In this work, using molecular dynamics simulations, we further investigate the role of the temperature T (from 285 to 360 K) on the thermal conductivity enhancement of nanohybrid porous silicon and water system. Furthermore, by studying and analysing several structural and dynamical parameters of the nanoconfined water, we give physical insights of the observed phenomena. Upon increasing the temperature of the system, the thermal conductivity of the hybrid system increases reaching a maximum for T = 300 K. With this article, we prove the existence of new heat flux channels between a solid matrix and a nanoconfined liquid, with clear signatures both in the radial distribution function, mean square displacements, water molecules orientation, hydrogen bond networks and phonon density of states.