水溶液中影响声化学反应因素研究

【作者】 何玉芳；

【导师】 许文林； 王雅琼；

【作者基本信息】 扬州大学 ， 应用化学， 2006， 硕士

【摘要】 本文以超声作用下水溶液中的声致自由基化学反应为研究体系,对超声空化气泡运动过程进行了模拟求解、测定了溶液系统的超声输入功率、测定了超声作用下水中双氧水的累积浓度、碘量法测定了超声作用下水中自由基的生成量。探讨了超声作用时间、超声输出功率、溶液主体温度等因素对声化学反应效率的影响,为超声在工业中的应用提供理论依据和技术指导。1.超声空化气泡运动过程模拟及模型的求解建立了超声作用于均相液体中空化泡运动的动力学模型,模型中考虑了液相的动力粘度、表面张力和溶剂的蒸汽压对空化泡运动特性的影响,用MATLAB对建立的普遍化的模型方程进行了数值求解和过程模拟。探讨了超声在水介质中传播时超声的频率、功率和空化泡的初始平衡半径对空化泡运动规律的影响以及声压幅值和液相主体温度对空化泡崩溃时的泡内温度和压力的影响,为超声的空化效应在化工过程中的研究和应用提供了基础理论依据。2.量热法测定溶液系统的超声输入功率采用量热法测定了溶液系统的超声输入功率。输入溶液系统的超声功率随着超声波发生器输入功率的增加而增加,但并不随着输入功率的增加而呈线性的增加;输入溶液系统的超声功率大约为超声波发生器的输入功率的20%～30%,远小于超声波发生器输入功率。3.超声作用下水中累积的双氧水浓度的测定及其影响因素研究应用紫外可见光谱法对超声作用下水中双氧水的累积浓度进行了分析测定。探讨了超声作用时间、溶液系统超声输入功率、溶液主体温度对超声作用下水中双氧水的浓度的影响规律。结果表明,当其他条件一定时,水经19.6kHz的超声作用后能够生成双氧水,并且可以用碘量分光光度法测定超声作用下水溶液中双氧水的浓度;水中双氧水的浓度随着超声作用时间的增加而呈线性增加;超声作用20min后水中双氧水的浓度随着溶液系统超声输入功率的增加而增加;随着溶液主更多还原

【Abstract】 The sonochemical in aqueous solution were investigated. The bubble dynamic motion caused by ultrasound was moldeled and simulated using MATLAB. The input ultrasonic power of solution system was measured by calorimetry. The concentration of hydrogen peroxide in water and releasing iodine in potassium iodide solution was measured. The effect of ultrasound irradiating time, output power of ultrasound generator and temperature of bulk solution on the results were studied. And the aim of the research is to provide theoretical parameters and technical supply to the application of ultrasound in industry.1. Moldeling and simulation of bubble motion caused by ultrasound using MATLABThe model to describe bubble dynamic motion caused by ultrasound was presented, which included the effects of fluid viscosity, surface tension and vapor pressure of the solvent. The general model equation was solved and the cavitation process was simulated using MATLAB. The effects of the factors, such as the ultrasonic frequency, the ultrasonic intensity and the initial radius of the bubble, on the bubble motion and cavitation process, and the maximum temperature and pressure affected by bulk solution temperature and the ultrasonic intensity in collapsing bubble were discussed in aqueous solution. The simulation results show that the frequency, the ultrasonic intensity and the initial radius of the bubble have great effects on the bubble dynamics and cavitation process and both of the maximum temperature and pressure are very sensitive to the bulk solution temperature and the ultrasonic intensity. This work provides a very important basis for the application of ultrasound to a variety of chemical systems.2. Measuring of input ultrasonic power of solution system by calorimetryThe input ultrasonic power of solution system was measured by calorimetry. The input ultrasonic power of solution system was went up with the input power of the generator nonlinearly, and it was much lower than the input power, about 20 to 30 percent of the input power of generator.更多还原