The Chemical Effects of Ultrasonics

Abstract

A study of the effects of ultrasonics on the inversion of sucrose was made and negative results were obtained. In the light of these results one can make the following conclusions. Chemical reactions attributed to ultrasonics can be classified according to three mechanisms. (1) Reactions due to cavitation never occur without the formation of bubbles. All of these reactions take place in the gas phase, are primarily thermal and are due to the heat developed during adiabatic compression. Thus, only reactants with an appreciable vapor pressure are affected. (2) Many reactions in the liquid phase are of secondary origin due to reactions with dissolved products of the primary reaction in the gas phase. Luminescense is also a secondary effect. (3) Some reactions are due to the uniform temperature elevation caused by absorption of acoustic energy of very high intensity in a short path length.