Thermophysical characteristics of water-in-FC72 nanoemulsion fluids

The use of solid particles has long been a common way of increasing fluid thermal conductivity. Here, nanoemulsion fluids—dispersions of liquid nanodroplets—are proposed. As an example, water-in-FC72 nanoemulsion fluids are developed, and their thermophysical properties and impact on natural convective heat transfer are investigated experimentally. The increase in conductivity and viscosity of the fluids is found to be nonlinear with water loading, indicating an important role of the hydrodynamic interaction and aggregation of nanodroplets. A very remarkable increase in effective specific heat—about 126% for 12vol% water loading—occurs in the fluids due to melting-freezing transition of water nanodroplets.