论文总字数：25889字

摘 要

大气压等离子体射流(APPJ)作为一种新型的等离子体产生方式，能够实现放电区域和工作区域分离，并且通过气流和电场的作用使得放电区域中的等离子体喷出管口，将等离子体中产生的活性粒子携带到所需处理物体的表面，具有较强的灵活性和实用性，因此在生物医药、杀菌消毒、聚合物材料表面改性、薄膜沉积等应用领域有着广泛的应用前景。但是目前对大气压等离子体的研究主要是基于单一的惰性气体为主要工作气体，如Ar、He、Ne等，在这种单一的工作气体环境下，对材料表面改性的效果不是很理想，有研究者发现在惰性气体中添加少量的活性成分有助于提高等离子体射流产生的活性粒子，可有效提高改性效果，然而对可产生有效活性粒子NH的活性成分NH₃的射流研究还不多，对其放电演变规律、活性粒子变化以及不同影响因素对射流放电特性的影响还没有系统全面的研究。为了获得最佳的放电条件和得到最强活性粒子时的比例，需要进行大量的实验和理论研究，系统的掌握其放电特性及放电演变规律。

本文分别在纯Ar气体和Ar/NH₃混合气体两种工作气体环境下，实现了稳定的一维单管等离子体射流。通过各种测量手段对其电气特性(电压-电流波形、Lissajous图形)和光学特性(发光图像、发射光谱图)进行了诊断和分析，给出了等离子体射流稳定运行的条件和参数范围。再进一步分析NH₃活性成分添加后，含量变化对射流放电的影响，结合发射光谱中主要活性粒子的谱线强度变化，获得添加活性成分NH₃时产生最多活性粒子的比例。

实验研究表明，以纯Ar作为工作气体时，利用高频交流电源驱动实验装置，在频率为10kHz，气体体积流速为4L/min、外加电压为30kV时，等离子体射流放电强度最强。在稳定的一维单管Ar等离子体射流中加入氨气，发现随着NH₃含量的升高，射流的放电强度逐渐减弱。在氨气浓度达到0.012%、外加电压达到30kV时，射流长度最长，喷出管口距离达到26mm，同比增长了18.18%。相较于纯氩，添加氨气后多出NH(326nm)谱线，且当氨气含量为0.012%时，NH(326nm)谱线强度最强，其他粒子成分相同，但粒子谱线强度有不同程度上的减弱。

关键词：大气压低温等离子体射流 电气特性 发光特性 光谱特性 氨气

Effect of the addition of different active components on the discharge characteristics of the jet

ABSTRACT

Atmospheric pressure plasma jet (APPJ) is a new discharge mode in the recent years; it has realized the separation of the discharge area and the working region. With the effect of air flow and electric field, the plasma jet out nozzle, carrying the active particles to the surface of an processing object. For its flexibility and practicality, there’s a broad application of plasma jet in biological medicine, sterilization, polymer materials surface modification, thin film deposition and other fields. At present, the study of atmospheric pressure plasma is mainly based on single working gas, such as Ar, He, Ne, et al. In such working gas, the effect of material surface modification is not very well. some researchers have found that adding a small amount of active ingredient in an inert gas is helpful to improve the generation of active particles, which can effectively improve the effect of modification. However, the plasma jet with few studies on the use of active ingredient of NH₃ which can produce NH is not much. There’s no system research of its discharge evolution law, the change of active particles and the influence of the different factors affecting the plasma jet electrical properties. In order to get the best discharge conditions and get the strongest active particles, a lots of experimental and theoretical studies are needed, to master its discharge characteristics and discharge evolution law.

In this paper, a stable one-dimensional single-tube plasma jet was carried out in Ar and Ar/NH₃ working gas speratialy. By diagnosing electrical (Voltage-current waveforms, Lissajous figures) and the optical characteristic (Lighting emission pictures, Optical emission spectroscopy), the stable operation conditions and the parameter scope of APPJ are given based on the analysis of the experimental data. Finally, the best proportion of NH₃ is achieved by analyzing the effect of adding NH₃ to the discharge characteristic, combining with the change of main active particles.

Studies have shown that, when Ar was used as working gas, the power frequency was 10kHz, the flow rate reached a critical value of 4L/min, and the applied voltage was 30kV, plasma jet discharge intensity was strongest. When adding NH₃ to the stable Ar plasma jet, the discharge intensity was getting weak with the content of NH₃ increasing. When the content of NH₃ was 0.012%, applied voltage was 30kV, the length of plasma jet reached 26mm, increased of 18.18%. Compared with pure argon, NH (326nm) lines were added after adding ammonia gas, and the other particles had the same composition, but the particle strength was weakened to some extent.

Keywords: Atmospheric Low Temperature Plasma Jet; Electrical characteristics; Optical characterestic; Spectral characteristics; Ammonia

目录

摘 要 I

ABSTRACT II

目 录 III

第一章 绪 论 1

1.1 大气压等离子体 1

1.2 等离子体射流特性及结构 2

1.3 等离子体射流的研究意义及应用 3

1.4 等离子体射流国内外研究进展 4

1.5 本文主要研究内容 7

第二章 实验装置及测量诊断 8

2.1 实验装置 8

2.2 诊断系统 8

2.2.1 电气特性诊断 8

2.2.2 光学特性诊断 9

2.2.3 光谱特性诊断 10

第三章 纯Ar等离子体射流放电特性研究 11

3.1电气特性 11

3.2发光特性 14

3.3光谱特性 16

3.4本章小结 19

第四章 大气压Ar/NH₃等离子体射流放电特性研究 20

4.1放电特性的诊断 20

4.1.1 电气特性 20

4.1.2 发光特性 22

4.1.3 光谱特性 22

4.2 氨气含量对大气压等离子体射流放电特性的影响 28

4.2.1对电气特性的影响 28

4.2.2对发光特性的影响 38

4.2.3对光谱特性的影响 29

4.3 本章小结 32

第五章 结 论 33

参考文献 34

致谢 37

第一章 绪 论

1.1 大气压等离子体

等离子体时近几十年来发现的一种新形式的物质存在状态，是在传统三态以外的一种基本状态。等离子体在平时的工作生活中越来越广泛的存在。相对于传统的三种物质存在状态来说，等离子体在成分与专属特性上来由有着本质的差别，主要表现在以下三点：首先，等离子体中所含有的各种粒子使等离子体具有导电的性质；其次，等离子体中各种粒子会受到电磁场的作用，在此作用下，发生了能量的转变；最后，等离子体由于库仑力的作用，在发生反应时类似于一个整体在作用。

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