(144a) Production of Pickering Emulsions: Forces Involved During Stabilization

Conventional emulsions are encountered in numerous industrial fields and since the pioneering work of Pickering and Ramsden a hundred years ago it has also been known that fine solid particles can be used as emulsifiers. It is also well established that correctly selected particles produce emulsions that are more stable than the ones stabilized with chemical surfactants. The characterization of these systems and their features have been investigated, such as the effect of the particles contact angle, their concentration, shape and size, the effect of aqueous phase pH and ionic strength and the effect of oil phase polarity and viscosity. In the light of the available work, it is obvious that it is possible to use particles to stabilize emulsions at the industrial scale. Unfortunately, the currently available information is not sufficient to design processes or to develop predictive models of the emulsions behavior. Being interested in emulsification process design, we are developing a methodology to predict the solid stabilized emulsions properties from the process conditions. The present work aims at developing a model describing droplets stabilization on the basis of particle adsorption forces measurements using Atomic Force Microscopy. This approach allows us to identify the main parameters affecting the particles adsorption mechanism and therefore the stabilization rate, a condition to predict the droplets distribution size during the emulsification process.