Open Access Nano Express

Thermal conductivity and viscosity of self-assembled alcohol/polyalphaolefin nanoemulsion fluids

Jiajun Xu1, Bao Yang1* and Boualem Hammouda2

Author Affiliations

1 Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA

2 National Institute of Standards and Technology, Center for Neutron Research, Gaithersburg, MD 20899, USA

For all author emails, please log on.

Nanoscale Research Letters 2011, 6:274  doi:10.1186/1556-276X-6-274

Published: 31 March 2011

Abstract

Very large thermal conductivity enhancement had been reported earlier in colloidal suspensions of solid nanoparticles (i.e., nanofluids) and more recently also in oil-in-water emulsions. In this study, nanoemulsions of alcohol and polyalphaolefin (PAO) are spontaneously generated by self-assembly, and their thermal conductivity and viscosity are investigated experimentally. Alcohol and PAO have similar thermal conductivity values, so that the abnormal effects, such as particle Brownian motion, on thermal transport could be deducted in these alcohol/PAO nanoemulsion fluids. Small angle neutron-scattering measurement shows that the alcohol droplets are spheres of 0.8-nm radius in these nanoemulsion fluids. Both thermal conductivity and dynamic viscosity of the fluids are found to increase with alcohol droplet loading, as expected from classical theories. However, the measured conductivity increase is very moderate, e.g., a 2.3% increase for 9 vol%, in these fluids. This suggests that no anomalous enhancement of thermal conductivity is observed in the alcohol/PAO nanoemulsion fluids tested in this study.