| AVS 55th International Symposium & Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS-ThP |
| Session: | Plasma Science Poster Session |
| Presenter: | N. Fujikawa, Nagoya University, Japan |
| Authors: | N. Fujikawa, Nagoya University, Japan N. Saito, Nagoya University, Japan O. Takai, Nagoya University, Japan |
| Correspondent: | Click to Email |
Solution Plasma (SP) is defined as a nonequilibrium discharge phenomenon in liquid solution. The higher reaction rate is expected since it supplies UV light, electrons, and radicals to liquid phase. SP processing is one of attractive reaction field for nano materials synthesis. However, there are few reports on solution plasma processing, in particular, fundamental research. We had been successful to fabricate various nanoparticles such as Au, Pt, FePt, In2O3 by SP processing. The reaction mechanism in the solution plasma has not been understood in detail. Reduction must be mainly occurred on these syntheses. However, oxygen and oxygen radical also be produced in the solution plasma. Why does not oxidation proceed? There are many other questions in SP processing. In this study, we aimed to investigate influences of dissolved substance, eg. O2, ions on the reactive species in the solution plasma. A pulsed power supply was utilized to generate plasma. Needle-shaped tungsten (diameter: 1 mm) was utilized as an electrode. Voltage between electrodes, pulse width and frequency were 2400V, 2μs and 15kHz, respectively. Optical emission spectra were measured with a emission spectrophotometer. Ar or O2 gases were introduced into the solution in order to vary the amount of dissolved oxygen. Discharge time was 30min. and solution temperature was varied from 10 to 30oC. Moreover, several kinds of chlorides were added into liquid solution in order to observed influences of ions. Peaks attributed to Hα, Hβ, Hγ and O were observed in optical emission spectra. The presence originated from decomposition of water. The each intensity is almost constant although the flow rates of O2 and Ar gases varied. From this, dissolved oxygen did not have a great effect on plasma state. On the other hand, peaks attributed to cation produced from chlorides were observed although peaks of chlorine were not observed. These differences would be discussed from the viewpoint of mobility in the solution, molecular weight, molecular or ion radius, and the reactivity of activated species.