Exploring the significance of interfacial molecular interactions on the specific heat, thermal conductivity and dynamic viscosity of nanofluids

International audienceAn optimal use of heat transfer nanofluids in systems for energy conversion and storage requires proper understanding on why the physical properties of the base fluid are modified in presence of nanomaterials. This work aims to rationalise the observed increment in the specific heat, thermal conductivity and dynamic viscosity of Pd nanoplate-containing aromatic oil-based nanofluids. Specific heat, thermal conductivity and dynamic viscosity have been characterised as a function of the nanoplate mass fraction and temperature. Maximum enhancements of17.4% in specific heat and 23.5% in thermal conductivity with negligible change in dynamic viscosity were found. Calculations at the density functional theory level-of-theory reveal strong chemisorption of the base fluid molecules on Pd surfaces. Via molecular dynamics simulations, this layer is demonstrated to be responsible of the improved specific heat and absence of rheological penalty, whereas it hinders heat conduction, forwhich enhancement the Pd nanoplate is solely responsible