Interfacial molecular layering enhances specific heat of nanofluids: Evidence from molecular dynamics

Abstract

It is well known that the specific heat of a heat transfer fluid can be significantly improved by the addition of nanoparticles to form a so-called nanofluid, but the origin of the effect is not completely understood yet. Here, we use molecular dynamics simulations in a nanofluid consisting of palladium nanoparticles in a commercial heat transfer fluid, to demonstrate that a significant fraction (nearly half) of the specific heat enhancement associated to the presence of the nanoparticles is due to strong chemisorption interaction of the fluid molecules at the nanoparticle surfaces. This insight opens new avenues for the nanofluid research community by providing sufficient understanding on the role of chemical interactions in the specific heat of nanofluids, helping on the discussion of what materials and base fluids to be chosen for the optimisation of the thermophysical properties of nanofluids and promoting the transition from basic research to actual application in energy conversion and thermal management processes.