Acoustic cavitation and sonochemistry

Sonochemistry is the use of cavitation for achieving a chemical conversion. When microbubbles are driven in the nonlinear regime, localized extreme temperatures (up to 10000 K) and pressures (up to 1000 bar) can be reached upon collapse, the surrounding liquid remaining ambient,thus giving origin to intriguing phenomena, such as light emission (sonoluminescence) and high temperature chemical reactions (sonochemistry). These reaction products then diffuse outside the bubble and dissolve inside the surrounding liquid. Due to their unstable nature, they are highly reactice and have therefore a vast potential for technological applications, eg. chemical synthesis, water cleaning, cells disruption and textile processing. However, sonochemical reactors are known to suffer from a lack of efficiency and controllability, which has until now prevented the large-scale employment of this technology. When we started the present study the challenge was to improve the efficiency of a sonochemical reactor, by reducing its dimensions to a micrometric scale, still retaining the possibility to control the precess.