Ultrasonic Effects in Electrochemical Processes

电极过程的反应控制在合成电化学中是重要的。因此，迄今为止，电极界面的功能改性受到广泛关注。本文提出了利用超声波对电极界面进行改性的新概念，并对超声波在有机电极过程中的作用机理进行了研究。从实验和理论两方面分析了超声波的空化效应是由于超声波在高于空化阈值的功率下辐照促进了电极界面的传质而引起的，并考察了电解槽、电极和超声振荡器的放置位置对电极反应的影响，为超声波的电化学应用提供了依据。结果发现，电极反应受组分位置的影响很大， 关于我们 这是因为纵向超声波在液体中传播时会产生反射、干涉和衰减。因此，有必要考虑组分的位置。此外，超声波对有机电过程的影响已经在一系列的研究中得到了广泛的研究。超声波对有机电化学反应的电流效率和产物选择性有很大影响。此外，在超声辐射下，电氧化聚合可以制备出二维和三维致密均匀的聚合物膜，并发现邻二溴的还原脱溴反应的立体选择性明显依赖于超声频率。特别是，立体选择性控制的一种新的效果，在MHz范围内的超声波，或者在kHz范围内的空化现象。从机理上考虑，发现在MHz范围内的超声波的作用是由于vic-二溴化物的超声波再脱位。这一事实将产生一个新的发展声化学。从这项研究中，它是说，超声提供了一个有用的方法，有目的的反应控制在各种电有机过程。少

Reaction control of electrode processes is important in synthetic electrochemistry. Therefore, functionality-modification of the electrode interface has received much attention so far. In this work, a new concept for the electrode interface modification is established by means of ultrasonic effects.This approach governs the structure of the work.At first, a mechanistic study on ultrasonic effects in organic electrode processes was carried out. From experimental and theoretical considerations, it was varified that the effects are caused by promotion of mass transport in the electrode interface by ultrasonic irradiation at a power higher than the cavitation threshold value.Hence, influences of placement of electrolytic cell, electrode and ultrasonic oscillator on electrode reactions were also examined in order to establish a guideline for electrochemical application of ultrasounds. As a result, it was found that the electrode reactions were greatly affected by placement of the constituen … More ts since longitudinal ultrasonic waves traveling in liquid would cause reflection, interference and attenuation. Therefore, it is necessary to take account for the placement of constituents.Moreover, effects of ultrasounds on electroorganic processes have been extensively examined in a series of investigations. The current efficiency and / or product selectivity in electroorganic reactions were found to be greatly affected by ultrasonic waves. In addition, the two- and three-dimentionally dense and uniform polymer films could be prepared by electrooxidative polymerization under ultrasonic irradiation.It was also found that stereoselectivity in the reductive debromination of vic-dibromides remakably depends on the frequency of ultrasounds. In particular, the stereoselectivity was controlled by a novel effect of ultrasounds at MHz ranges, alternatively to the cavitation phenomenon at kHz ranges. From the mechanistic consideration, it was found that the effect of ultrasounds at MHz ranges is due to the ultrasonic reluxation of vic-dibromides. This fact would produce a new developments in sonochemistry.From this study, it was stated that ultrasounds offer a useful method for purposive reaction control in a variety of electroorganic processes. Less