Nanodiamond-Based Thermal Fluids

Dispersions of nanodiamond (average size ∼6 nm) within dielectric insulator mineral oil are reported for their enhanced thermal conductivity properties and potential applications in thermal management. Dynamic and kinematic viscosities—very important parameters in thermal management by nanofluids—are investigated. The dependence of the dynamic viscosity is well-described by the theoretical predictions of Einstein’s model. The temperature dependence of the dynamic viscosity obeys an Arrhenius-like behavior, where the activation energy and the pre-exponential factor have an exponential dependence on the filler fraction of nanodiamonds. An enhancement in thermal conductivity up to 70% is reported for nanodiamond based thermal fluids. Additional electron microscopy, Raman spectroscopy and X-ray diffraction analysis support the experimental data and their interpretation.