- 學位論文
大氣介電質阻擋放電平面電漿應用於刀具滅菌之研究
The Study of Atmospheric Pressure Dielectric Barrier Discharge Plane Plasma Apply to Sterilization of Bacterial on Knife Surface
摘要
台灣地處高濕度與溫暖的亞熱帶，食物中毒案例屢見不鮮。多項研究指出，食物中毒的主因為餐廚具未確實清潔，易滋生大腸桿菌與金黃色葡萄球菌，造成汙染所致。大氣電漿具有豐富的活性物種，對滅菌有相當良好的效果，近年來廣泛應用於生物醫學相關領域。本研究利用大氣介電質阻擋放電電漿技術，設計出單層與多層反應器刀具滅菌系統。本系統在大氣環境中即可激發電漿，激發之工作頻率為4.082 kHz；工作電壓為3.55 kV；電流大小為0.723 A；消耗功率為6.51 W，激發時間在35分鐘時，刀具溫度低於攝氏43度；光學放射光譜儀在波長297 nm和777 nm，檢測出活性氧物種OH與O存在。本研究分別檢測本電漿系統對大腸桿菌與金黃色葡萄球菌之滅菌效率，結果發現可使此兩株食源性細菌在10分鐘與30分鐘達到完全滅菌。因餐廚具使用環境濕度高，因此亦進行在相對濕度90%下，驗證本系統仍能正常運作。另為充分瞭解本電漿系統的滅菌機制，以掃描式電子顯微鏡分析處理前後細菌之形貌，結果發現處理後細菌表面產生皺縮、破裂與變形。證實本電漿系統具有離子轟擊與活性物種氧化等多重滅菌機制。最後進行電漿處理後靜置之滅菌實驗，證實滅菌後無滅菌物種殘留。
並列摘要
Food poisoning is common in Taiwan. A subtropical climate with high humidity and warm environment makes it easier for bacteria to breed. The researchers pointed out that the main source of food poisoning can be attributed to kitchenware not being cleaned properly which causes bacterial contamination. In recent years, the application of atmospheric plasma in biomedical related fields have been a fairly extensive research. Atmospheric plasma reactive species (electrons, ions and free radicals) used for sterilization have shown good results. This study used atmospheric dielectric barrier discharge plasma technology designed to produce a set of single knives sterilization system and a set of multi-knives sterilization system. The configuration for sterilization system are the following: plasma excitation frequency of 4.082 kHz; working voltage of 3.55 kV; current of 0.723 A; power consumption of 6.51 W and excitation time for35 minutes when the temperature on knife is lower than43°C. Optical emission spectroscopy at 297 nm and 777 nm wavelengths were used to detect the presence of active oxygen species OH- and O-.For sterilization efficiency testing, two strains of food borne bacteria, Escherichia coli and Staphylococcus. aureus were used and found that the sterilization system allows E. coli and S. aureus to be completely sterilized within 10 minutes and 30 minutes respectively. Sterilization experiments were also carried out at 90% relative humidity environment and confirmed that the system can still work properly. In order to understand the mechanism of the plasma sterilization system, scanning electron microscope were used for the analysis of bacterial surface topography before and after plasma treatment. It was found that after plasma treatment, the bacteria showed shrinkage, cracking and deformation phenomenon due to ion bombardment of the sterilization system and oxidation of atmospheric plasma active species. Moreover, no residual sterilizing species were found after plasma treatment sterilization experiments.