마이크로웨이브 플라즈마 토치와 응용
A MICROWAVE PLASMA TORCH AND ITS APPLICATIONS
- 주제(키워드) 마이크로웨이브 플라즈마 , MICROWAVE PLASMA , 토치
- 발행기관 아주대학교 대학원
- 지도교수 엄환섭
- 발행년도 2008
- 학위수여년월 2008. 8
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 본문언어 영어
초록/요약
In the first subject of this dissertation, various materials powder such as TeO2, TiC, and AlF3 was directly synthesized by employing microwave plasma at atmospheric pressure. Also, we investigate characteristics of as-synthesized TeO2, TiC, and AlF3 nanopowders, respectively. The second subject addresses the pulsed microwave plasma torch treatment of aluminum surface (Al). The surface treatment of Al sheets using atmospheric pressure pulsed-microwave plasma is investigated in terms of gas mixtures. The total surface free energy of the Al sheets before and after the Ar/H2 plasma treatment, estimated from the Owens-Wendt equation, increased from 19.38 to 82.40 mN/m, showing, a significant improvement in hydrophilicity. The elimination of chemical and biological warfare agents as a stimulant was placed on the third subject of this dissertation. The burner flames were sustained by injecting hydrocarbon-fuels into the microwave plasma torch in air discharge. The FTIR and GC spectra indicated near perfect elimination of DMMP in the microwave plasma burner, respectively. As the final subject of this dissertation, Properties of microwave plasma torch operating at a low pressure was presented. The plasma profile at a low pressure is shown to be asymmetric with higher density on the incoming side of the microwaves. Gas temperature and electron density of the torch plasma measured by making use of OES from hydroxide radicals and electron density from hydrogen Balmer beta line is shown to increase drastically at high pressure operation, as the microwave power increases, respectively. Disintegration of nitrogen fluoride (NF3) indicates that a microwave plasma torch operating at a low pressure can efficiently generate an abundant amount of chemical radicals.
more목차
Abstracts = 1
Contents = 2
Chapter 1. Introduction = 6
1.1 Introduction to plasma = 6
1.2 Electrodeless Microwave Plasma Torch = 7
Chapter 2. Preparation of ultra-pure nanoparticles = 10
2.1. TeO₂ nanoparticles synthesized by atmospheric microwave plasma torch = 10
2.1.1. Introduction = 10
2.1.2. Experimental and Results = 11
- XRD and Williamson-Hall plot = 13
- SEM and TEM images = 15
- BET measurements = 17
2.2. Synthesis of TiC nanocrystalline powder by microwave plasma = 19
2.2.1. Introduction = 19
2.2.2. Experimental and Results = 20
- SEM images of as-produced sample = 22
- XRD patterns of the as-produced powder = 23
- Williamson-Hall plot of using XRD patterns = 23
- TEM images of as-produced sample = 24
2.3. AlF₃ synthesized in atmospheric microwave plasma torch-flame = 26
2.3.1. Introduction = 26
2.3.2. Experimental and Results = 27
- XRD patterns and SEM image of the as-produced powder = 28
- Williamson-Hall plot of corresponding to the XRD pattern = 29
- FTIR spectrum of as-produced powder = 30
- BET measurements = 31
Chapter 3. Surface treatment of aluminum sheets = 33
3.1. Introduction = 33
3.2. Experimental and Results = 34
- Photograph of the pulsed microwave plasmas = 37
- Optical emission spectra of Ar, Ar/O₂, Ar/H₂, respectively = 39
- Shapes and contact angles of water drops placed on Al samples = 40
- SEM images showing the Al surface morphologies = 41
- Plots of the contact angle versus time and Owens-Wendt plot = 42
Chapter 4. Elimination of Dimethyl Methylphosphonate(DMMP) by plasma flame = 46
4.1 Introduction = 46
4.2. Destruction of DMMP using a O₂-Microwave Plasma Torch = 47
4.2.1. Experimental and Results = 47
- The FTIR spectra of the discharge gas from DMMP destruction with additional oxygen at rates = 49
- GC spectra of samples of the intermediary compounds collected from the inner surface of the reaction chamber = 51
4.3. Elimination of DMMP by plasma flame made of microwave plasma and burning hydrocarbon fuel = 53
4.3.1. Experimental and Results = 53
- Axial and radial temperature profile = 55
- The FTIR spectra of using the CH₄, kerosene+air, kerosene+O₂ fuels destruction = 56
- GC spectra from the inner surface of the reaction chamber after DMMP destruction = 57
- Plots of F/(I+F) versus the DMMP injection rate = 58
Chapter 5. Microwave plasma torch operating in a chamber at a low pressure = 60
5.1. Introduction = 60
5.2. Experimental and Results = 61
- Plots of the microwave power required for gas breakdown = 63
- A photograph of a torch flame = 63
- Profile of simulated optical emission of OH radicals = 65
- Measured data of the flame temperature = 66
- Emission profiles of the hydrogen Balmer beta line of the plasma torch = 67
- Plots of the plasma density versus the microwave power = 68
- Plots of the reflected microwave power versus NF₃ flow rate = 70
- Picture image of the emission from an air cloud exited = 71
- FTIR spectra before and after a microwave plasma torch = 72
- Plots of measured data of DRE versus the NF₃ flow rate = 73
Chapter 6. Conclusion = 75
References = 79
Publication List = 86
