Sonoluminescence of Inorganic Ions in Aqueous Solutions

Abstract

Sonoluminescence from alkali-metal salt solutions reveals excited state alkali – metal atom emission which exhibits asymmetrically-broadened lines. The location of the emission site is of interest as well as how nonvolatile ions are reduced and electronically excited. This chapter reviews sonoluminescence studies on alkali-metal atom emission in various environments. We focus on the emission mechanism: does the emission occur in the gas phase within bubbles or in heated fluid at the bubble/liquid interface? Many studies support the gas phase origin. The transfer of nonvolatile ions into bubbles is suggested to occur by means of liquid droplets, which are injected into bubbles during nonspher..