Thermal Conductivity and Viscosity of Nanofluids Containing Chain-like Silver Clusters

Ag nanofluids with different concentration (0.03 similar to 0.12vol%) were prepared by dispersing chain-like Ag clusters into ethylene glycol. The thermal conductivity and rheological behaviors of the Ag nanofluids were investigated at temperatures ranging from room temperature (15.8 degrees C) to 65 degrees C. The results show that the Ag nanofluids is Newtonian flow. The relative viscosity of the Ag nanofluids increases with the raise of particle volume fraction and is independent of temperature. The effective thermal conductivity of the Ag nanofluids increases with the particle volume fraction and temperature. It implies that the Ag nanofluids are better than the base fluid as heat transfer fluids especially in high temperature conditions. The viscosity and effective thermal conductivities of the Ag nanofluids can not be predicted by present models, and more work is needed to be done in the future.