Ultrasonic Effects in Electrochemical Processes

电极过程的反应控制在合成电化学中具有重要意义。因此，电极界面的功能修饰一直备受关注。本文提出了利用超声效应修饰电极界面的新概念。这种方法支配着工作的结构。首先，对超声波在有机电极加工过程中的作用机理进行了研究。从实验和理论两方面考虑，认为这种效应是由高于空化阈值的超声辐照促进电极界面的质量输运引起的。因此，研究了电解槽、电极和超声振荡器的放置对电极反应的影响，以期为超声的电化学应用提供指导。结果表明，由于纵向超声波在液体中传播会引起反射、干扰和衰减，因此本构元的放置对电极反应有很大的影响。因此，有必要考虑到成分的放置。此外，超声波对电有机过程的影响已经在一系列的研究中得到了广泛的研究。发现超声波对电有机反应的电流效率和/或产物选择性有很大的影响。此外，超声辐照下电氧化聚合可制备二维和三维致密均匀的聚合物薄膜。研究还发现，双溴化铋还原脱溴反应的立体选择性显著地依赖于超声频率。特别是，立体选择性是由超声波在MHz范围内的新效应控制的，而不是在kHz范围内的空化现象。从机理上考虑，超声在MHz范围内的作用是由双溴化物的超声松弛引起的。这一事实将导致声化学的新发展。从这项研究中，我们指出超声波为各种电化学过程的有目的的反应控制提供了一种有用的方法。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