Ultrasonic Effects in Electrochemical Processes

电极过程的反应控制在合成电化学中占有重要地位。因此，到目前为止，电极界面的官能化修饰受到了广泛的关注。在这项工作中，建立了一种利用超声波效应进行电极界面修饰的新概念，这种方法控制了工作的结构。首先，对有机电极过程中超声波效应的机理进行了研究。从实验和理论两个方面分析了该效应是由于高于空化阈值的超声波辐照促进了电极界面的传质所致，并考察了电解槽、电极和超声振荡器的位置对电极反应的影响，以期为超声的电化学应用提供指导。结果发现，组成…的位置对电极反应有很大影响由于纵向超声波在液体中传播时会产生反射、干扰和衰减，因此会产生较大的温度。因此，有必要考虑成分的放置。此外，超声波对电有机过程的影响已经在一系列研究中得到了广泛的研究。研究发现，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，在超声波辐射下，电氧化聚合可以制备二维和三维致密、均匀的聚合物薄膜。研究还发现，二溴化钒还原脱溴反应中的立体选择性与超声频率有关。特别是，立体选择性是由在MHz范围的超声波的一种新的效应控制的，而不是在khz范围内的空化现象。从机理上考虑，在MHz范围内的超声波效应是由于二溴化钒的超声再置换所致。这一事实将导致声化学的新发展。从这项研究中可以看出，超声波为各种电有机过程中的有目的的反应控制提供了一种有用的方法。较少

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