利用常壓微電漿裝置進行水酸化之研究

Water Acidification by Atmospheric Pressure Microplamas Operated in Air

林展誠(Chan-Cheng Lin)

指導教授 ： 徐振哲

國立臺灣大學/工學院/化學工程學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201701655

摘要

常壓微電漿系統因不需要真空系統，且電子密度和能量密度高而具有局部高反應性，在近年來有許多相關的研究被報導。其中，利用此系統於空氣下處理目標物，在近幾年來受到生醫領域的學者關注，因為電漿與空氣反應後所產生的化合物有殺菌之效果。
本實驗利用一交流電驅動低成本常壓微電產生系統(Microplasma generation devices, MGD)以產生任意維度小於1 mm之電漿進行實驗。此裝置為一介電質放電型微電漿系統，主要是由兩層電極和介電質組成一「電極-介電質-電極」之結構，而其電極圖樣製作方法為碳粉轉印法，此方法之優點為圖樣可客製化、製作時間短且操作簡單，相當有利於實驗開發階段之研究。
本實驗為利用上述之裝置進行水酸化研究。提供一交流電使此裝置產生電漿，並利用電漿與空氣反應，進而產生主要產物，如：二氧化氮(NO2)、過氧化氫(H2O2)等，再藉由電漿產生的流動現象，將這些產物送往距離電漿約3-5 mm的去離子水滴(約10μL)，並溶解於水中進行反應而達到酸鹼值下降之效果。其中，形成此流動現象的原因為電漿中的離子所造成，因為周遭電場的影響，使離子會順著電場方向移動，並與氣體中的分子相互作用，使氣體形成一流動。於研究中利用一簡易粒子圖像測速系統偵測氣體流速，並觀測其流場。實驗改變電源供應頻率和電壓、電極幾何參數，觀察氣體流速和流場的變化，並探討其與酸化速度的關係。實驗結果顯示利用此裝置可在數十秒內使水的酸鹼值達到3，且當電壓、頻率以及流速增加時，可加快水酸化的速度，並且可以利用不同的電極圖案改變流場，進而改變酸化速度。

關鍵字

常壓微電漿 ； 水處理

並列摘要

Many researches of atmospheric-pressure microplasma system has been reported in the recent year, because it can be operated without vacuum system, and it has a lot of advantages, such as high electronic density, high energy density and high reactive in the local area and so on. Atmosphere microplasma system has been also paid attention by the researchers of biomedical engineering, because using the system to treat sample in air can be sterilized by compounds which is produced from reaction of plasma and air.
The research used a low-cost and atmospheric-pressure microplasma generation system (MGD) which was driven by AC as an experimental device, and the device can produce microdischarges below 1 mm at any dimension. The device was a dielectric-type MGD which was composed by two electrodes and dielectric, and it had a sandwich structure of “electrode-dielectric-electrode”. The electrode pattern of device was fabricated by Toner Transfer Method, and the device had many advantages, such as customized, short fabricated time and easy operation, so it was suitable for research of laboratory investigation.
The investigation used above device to conduct experiment of water acidification. By applying a high voltage to MGD to generate plasma, and the system formed key products which was reacted by plasma and air, such as NO2. The products was transported to 10 μL of DI water droplet which was sit adjacent to the plasma generation electrode of the MGD with a distance of 3-5 mm by a stream formed by MGD, and the pH value decreased from 5.5 to 3 in 60 seconds by the dissolving of NO2. The forming mechanism of the stream was that ions which was generated by MGD collided with molecular in air by affect of electronic field, then the collision caused the gas stream flew to direction of electronic field. In the research, flow velocity and flow pattern measured by a Particle Image Velocimetry (PIV) system which is made by our team. Experimental factors were including power-applied frequency, power-applied voltage and geometric parameters of electrodes. Results showed that higher flow velocity could be obtained under circumstances of higher frequency or higher voltage, and higher flow velocity caused higher acidification rate. Also, changing geometric parameters of electrodes could change flow pattern, and it effected acidification rate.

並列關鍵字

atmospheric-pressure microplasma ； water treatment

參考文獻

1. N. S. J. Braithwaite, "Introduction to gas discharges," Plasma Sources Science & Technology, 9 (4), 517-527 (2000).

3. D. Pappas, "Status and potential of atmospheric plasma processing of materials," Journal of Vacuum Science & Technology A, 29 (2)(2011).

4. C. Tendero, C. Tixier, P. Tristant, J. Desmaison and P. Leprince, "Atmospheric pressure plasmas: A review," Spectrochimica Acta Part B-Atomic Spectroscopy, 61 (1), 2-30 (2006).

5. K. Tachibana, "Current status of microplasma research," Ieej Transactions on Electrical and Electronic Engineering, 1 (2), 145-155 (2006).

6. F. Rossi, O. Kylian, H. Rauscher, M. Hasiwa and D. Gilliland, "Low pressure plasma discharges for the sterilization and decontamination of surfaces," New Journal of Physics, 11(2009).