Size dependent thermal conductivity of single-walled carbon nanotubes J. Appl. Phys. 112, 013503 (2012) Inter-tube thermal conductance in carbon nanotubes arrays and bundles: Effects of contact area and pressure Appl. Phys. Lett. 100, 261908 (2012) The thermal flash technique: The inconsequential effect of contact resistance and the characterization of carbon nanotube clusters Rev. Sci. Instrum. 83, 054904 (2012) Thermal stability of wetting layer in quantum dot self-assembly J. Appl. Phys. 111, 093526 (2012) Additional information on Appl. Phys. Lett.

2. Research Objectives Development and applications of nanoparticle analyzing techniques to examine their thermal behaviors in suspension, including the thermal conductivity, thermal (Brownian) diffusion, thermophoresis and thermocapillaryphoresis. 3. Itemized Progress 3-1. Development of a new miniaturized heated-wire conductivity measurement system Thermal conductivity measurements for CuO and Al 2 O 3 nanofluids have been performed with a newly-developed miniaturized heated-wire conductivity measurement device that require 10-ml capacity versus the first generation Argonne National Laboratory's system requiring 50-ml sample. The current data confirmed, within acceptable discrepancies, previously published data obtained by other research groups (Lee et al. 3 1999, Das et al. 4 2003) under identical conditions. Thus, the measurement accuracy of the newly developed miniaturized device has been validated. More detailed report is presented in Appendix 1. 3-2. Identification of surfactant effect on thermal conductivity When nanoparticles are mixed with base fluid, adding surfactant is essential to enhance the dispersion and minimize the coagulation of nanoparticles. Additionof surfactant, however, can unfavorably change the thermal characteristics of nanofluids. Using the developed miniaturized system, measurements have been made for thermal conductivities of nanofluids with surfactants. The results persistently show substantial decreases of the thermal conductivity in comparison with nanofluids with no surfactant mixed. In order to find the physical explanation for the reduced conductivity, both experimental and analytical studies are carefully explored to be implemented. More detailed report is presented in

Low thermal conductivity is a primary limitation in the development of energy-efficient heat transfer fluids required in many industrial applications. To overcome this limitation, a new class of heat transfer fluids is being developed by suspending nanocry stalline particles in liquids such as water or oil. The resulting “nanofluids” possess extremely high thermal conductivities compared to the liquids without dispersed nanocrystalline particles. For example, 5 volume % of nanocrystalline copper oxide particles suspended in water results in an improvement in thermal conductivity of almost 60% compared to water without nanoparticles. Excellent suspension properties are also observed, with no significant settling of nanocrystalline oxide particles occurring in stationary fluids over time periods longer than several days. Direct evaporation of Cu nano-particles into pump oil results in similar improvements in thermal conductivity compared to oxide-in-water systems, but importantly, requires far smaller concentrations of dispersed nanocrystalline powder.