Experimental Study of the Processes of Formation, Drift and Coalescence of Vapor-Gas Bubbles in Aqueous Solutions of Salts and Surfactants in a Sonochemical Reactor

Abstract

Abstract An experimental study of the activity of cavitation processes and the intensity of coalescence of vapor-gas bubbles arising in the volume of a liquid in the presence of ultrasonic (US) exposure in a NaCl salt solution and at various concentrations of sodium dodecyl sulfate (SDS) as a surfactant has been carried out. The process of bubble formation and drift was recorded using a highspeed camera in the plane of the cuvette illuminated by a laser knife. It is shown that the addition of a surfactant to an aqueous solution of NaCl salt leads to a partial inhibition of the coalescence of the observed bubbles and a change in the degassing mode of the liquid in the presence of ultrasonic treatment. The maximum activity of cavitation processes and the formation of vapor-gas bubbles was observed in the presence of salt and a low concentration of SDS. Thus, the presence of a surfactant in an aqueous solution of 0.1 M NaCl salt leads to a change in the growth dynamics of the bubble ensemble, since small bubbles are not able to float to the surface, due to the prevalence of viscous and vibrational forces over buoyancy force.