| AVS 59th Annual International Symposium and Exhibition | |
| Nanometer-scale Science and Technology | Thursday Sessions |
| Session NS-ThP |
| Session: | Nanometer-scale Science and Technology Poster Session |
| Presenter: | Y.K. Heo, Nagoya University, Japan |
| Authors: | Y.K. Heo, Nagoya University, Japan M.A. Bratescu, Nagoya University, Japan N. Saito, Nagoya University, Japan |
| Correspondent: | Click to Email |
In recent years, the development of high speed devices and their integrated circuits has facing some obstacles owing to localized heat generation in terms of safety and efficiency of devices. Nanofluids which were defined fluids containing nanometer-size particles, have been researched for their high and efficient heat transfer. It was reported that heat transfer enhancement was due to the Brownian motion of the nanoparticles contained in the fluids. Therefore, the diameter of nanoparticles in nanofluids is a key-factor in order to develop new heat transfer systems with higher energy-efficiency.
Recently our research group has developed a new synthesis method for well-defined nanoparticles in an aqueous solution, by solution plasma process (SPP). This process allows us to fabricate solutions containing high quantity of small monodispersed nanoparticles in order to obtain a heat transfer system with improved efficiency.
In this research, we aimed to reveal the heat transfer of nanofluids. The solution containing monodispersed gold nanoparticles was synthesized by SPP using a DC bipolar pulsed power supply. Gold nanofluids were synthesized with various concentrations of 0.1, 0.3, 0.6, 0.9 mM HAuCl4 and 4 times KOH of each HAuCl4 concentration in distilled water. The reaction time is 15 minutes. The solution plasma optical and electrical conditions were measured by OES and oscilloscope. The evaluation of the synthesized nanoparticles was performed by TEM analysis and UV vis spectroscopy. The dispersion stability was evaluated using zeta potential. In addition, KD2 pro & viscometer were used for heat transfer analysis of the synthesized nanofluids.
The decrease of the nanoparticles diameter from 13.8 ± 4.3 nm to 5.6 ± 1.4 nm was measured in dependence with the precursor concentration. The viscosity of the nanofludis increased with precursor concentration from 1.95 mPa·s to 2.05 mPa·s at 283 K (Viscosity of Di Water is 1.51 mPa·s.). A precursor concentration of 0.9 mM produced the smallest nanoparticles diameter of 5.6 ± 1.4 nm, and the highest increase of the thermal conductivity of 29.4 %.