| AVS 61st International Symposium & Exhibition | |
| Plasma Science and Technology | Tuesday Sessions |
| Session PS-TuP |
| Session: | Plasma Science and Technology Poster Session |
| Presenter: | Fei-Hung Huang, National Taiwan University, Taiwan, Republic of China |
| Authors: | F.H. Huang, National Taiwan University, Taiwan, Republic of China C.Y. Chou, National Taiwan University, Taiwan, Republic of China H.W. Chang, National Taiwan University, Taiwan, Republic of China C.C. Hsu, National Taiwan University, Taiwan, Republic of China |
| Correspondent: | Click to Email |
This work presents control of plasmas in saline solution using bipolar pulsed DC power. It is known that plasma of such a type generates inside the gas-phase that composes of water vapor, oxygen, and hydrogen through joule heating and/or electrolysis. We use a 1-ms-wide positive pulse of 550 V to ignite the plasma. Prior to this positive pulse, a 10-ms-wide pre-pulse is applied to generate electrolytic gas. By changing polarity the pre-pulse, namely positive pre-pulse (mode++), negative pre-pulse (mode-+), or without the pre-pulse (mode0+), the gas composition can be tailored. Optical emission spectroscopy shows OH, H, and O emissions, which implies that the plasma generates hydroxyl, H, and O radicals. We used a chemical probe, disodium salt of terephthalic acid, to quantify the formation rate of OH radicals using photoluminescence spectroscopy. To assess how the power type influences the efficiency in organic degradation, acid orange 7 (AO7) was chosen as the model organic materials. AO7 decolorization was quantified using ultraviolet-visible adsorption spectroscopy. AO7 degradation kinetics was fitted using 1st order kinetics. It is shown that mode-+ has a higher AO7 degradation rate constant as well as higher OH radical formation rate.