【作者】 周传华；

【导师】 陈砺；

【作者基本信息】 华南理工大学 ， 化学工艺， 2010， 硕士

【摘要】 等离子体的应用涉及物理、化学、工程等各个领域,长期以来一直是众多理论和实验研究的课题。辉光放电是产生低温等离子体的重要来源,在材料的表面改性、制氢、诱发或增强化学反应、直接或间接生成新物质、沉积碳膜等方面有着重要的应用,但辉光放电的电解机理和等离子体的具体化学行为还不是很清楚。本论文以正丙醇溶液为研究对象,对辉光放电等离子体电解(glow discharge plasma electrolysis,GDPE)过程进行分析。辉光放电电解过程能够产生稳定的等离子体。正丙醇溶液的GDPE电流电压特性曲线与水溶液、甲醇溶液和乙醇溶液GDPE电流电压特性曲线的相似。正丙醇溶液GDPE过程中电子是引发正丙醇分子等离子体化学反应的主要高能粒子,正丙醇分子在等离子体场内与高能粒子碰撞激发,产生大量活性粒子,各种活性粒子进一步反应生成各种产物。利用光发射光谱对正丙醇溶液GDPE过程进行分析:(1)研究正丙醇溶液GDPE过程活性物种的分布情况。(2)分析等离子体场内测得的活性物种的来源,产生过程及电子参数。通过气相色谱和气质联用仪分析正丙醇溶液GDPE阴极和阳极放电产物,研究发现:不同电压下,放电极性对正丙醇溶液GDPE产物无明显影响,主要差别在于阴极放电有固相产物生成,而阳极放电过程中未出现固相产物。当正丙醇的浓度低于75%时未出现苯、甲苯和固相产物。结合分子键能理论对电解主要产物进行分析。与甲醇和乙醇溶液GDPE产物比较可以发现:不同低碳醇GDPE气相主要产物都是H2、CO、CO2和烷烃。随着醇碳链的增长,溶液中逐渐出现了固相产物。本论文利用X射线光电子能谱、激光拉曼光谱和傅里叶红外光谱对正丙醇溶液中出现的固相产物进行分析,研究不同放电条件对固相产物的影响,结果发现固相产物的生成量随着正丙醇溶液浓度、放电电压和放电时间的增加而增加。放电电压和放电时间影响固相产物中sp2、sp3杂化碳的相对含量。更多还原

【Abstract】 Study on the application of plasmas involved in the fields of physics, chemistry and engineering is always an important topic for theoretical and experimental research. Being one of the important resources of cold plasmas, the glow discharge plays a significant role in urface modification of traditional materials, hydrogen production, induced or enhanced chemical reactions, directly or indirectly generate new material, deposited carbon film and so on. Because of the vagueness on plasmas chemical process and the specific chemical behavior of plasma in applications mentioned above, glow discharge plasma electrolysis(GDPE) on 1-propanol solutions were studied in this paper.The big volume and steady glow discharge plasmas were produced during GDPE on 1-propanol solutions. The characteristic curves of the voltage and current of GDPE on lower alcohols solutions were similar with that of GDPE on the aqueous solutions.Electrons were demonstrated as the most important radicals to trigger the plasma chemical reactions of 1-propanol during GDPE. Molecules of 1-propanol were bombed and excited in glow discharge plasmas and at the interface between plasmas and solutions and produced a lot of active radicals. The processes of GDPE on 1-propanol solutions were investigated by optical emission spectroscopy(OES). The source, energy level transition process and attribution of active species in the plasma field were investigated. The excitation energy of reactive species was related to their lowest excitation energy, the concentration of the electrolyte solutions had little influence on the composition of the plasma active species. The excited order of the plasma active species depended on the energy that the orbit transition of the species needed. The active species in the plasma field were found to undergo dissociation, ionization and excitation.The products of cathode and anode were detected by GC and GC/MS System, solid products were not found in anode GDPE. The main products of 1-propanol were similar with the products in different concentration of 1-propanol. Benzene, toluene and solid products were not appeared when the concentration of 1-propanol below 75%. The main products were analyzed using the molecular bonding energy theory.The differences of GDPE products among methanol, ethanol and 1-propanol solution were analyzed. The main products of gas were Hydrogen, Carbon monoxide, Carbon dioxide and alkanes. Solid products of the GDPE on 1-propanol solution were studied. The composition and structure were characterized by X-ray photo electron spectroscopy, Raman spectrometry and Fourier transformation infrared pecrtrometry. The relative content of sp2, sp3 hybrid carbon in solid products were influenced by discharge voltage and discharge time.更多还原