Synthesis ultrasonic-chemical processes

The simultaneous application of ultrasonic irradiation to an electrochemical reaction which has been termed sonoelectrochemistry has been shown to produce a variety of benefits in almost any electrochemical process. These include enhanced chemical yield in electrosynthesis and the control of product distribution improved electrochemical efficiency in terms of power consumption, improved mixing, and diffusion in the cell minimization of electrode fouling accelerated degassing and often a reduction in the amount of process-enhancing additives required. In a major chapter devoted to this topic, Suki Phull and Dave Walton have attempted to cover the majority of applications of ultrasound in electrochemistry including electrochemical synthesis, electroanalytical chemistry, battery technology, electrocrystallization, electroinitiated polymerization, and electroplating. 

In attempts to prepare homoallyl alcohol in an environmental friendly process, Andrews and co-workers reported its synthesis using a solvent-free method mediated by tin under ultrasound. Experiments showed that the alcohols were produced in excellent yields with aldehydes but that no products were produced using ketones. However, the existence of toxic allyltin compounds in the final products prevented the method from being applied downstream in fine chemical applications. On the other hand, according to Wang et carbonyl allylation reactions mediated by SnCl2 in aqueous solution without a Lewis acid under ultrasonic irradiation were successfully carried out. 

Many different methods have been reported for the production of metal oxide nanoparticles. The most common processes have been developed to synthesize oxide are chemical solution decomposition (CSD) [97], spray pyrolysis [98], CVD [99-101], two-step wet chemical method [102], sol-gel [103], ultrasonic irradiation [104,105], and ethanol thermal and hydrothermal method [106], Literature revealed that sol-gel is the most commonly used method for the preparation of metal oxide nanoparticles. It facilitates the synthesis of nanometer-sized crystallized metal oxide powder of high purity at a relatively low temperature [103]. 

---