A physical insight into sonochemical emulsion polymerization with cavitation bubble dynamics

This paper tries to explain the physical features of the sonochemical emulsion polymerization process by coupling experiments with different conditions (such as monomer type, saturation level of the medium and the type of bubbling gas) with a mathematical model for the radial motion of cavitation bubble. Experiments have been performed without any added chemical initiator or surfactant. Time variation of the mean size and size distribution of polymer particles in the emulsion have been used as a measure for the analysis. This measure is found to be governed by various parameters such as rate of radical production from the cavitation bubbles, magnitude of the microturbulence and shock waves produced by the cavitation bubbles, glass transition temperature of polymer and the population density of polymer particles. The relative magnitudes of these parameters vary significantly with the experimental conditions. This variation has been explained on the basis of results of simulation of radial motion of cavitation bubble. It is revealed that the mean particle size and size distribution of particles are manifestation of simultaneous and resultant influence of these parameters.