Influence of operational conditions on obtaining polystyrene nanoparticles.

Polymeric particles presenting sizes in the nanometric scale can be readily obtained by the miniemulsification/solvent evaporation technique using ultrasound as the energy source. The applicability of such nanoparticles dispersions depend on their stability and homogeneity during their use as drug carriers or as food and chemical additives. Moreover, nanoparticles size is important since it influences their efficiency as final products, regardless of their application. In this work polystyrene nanoparticles were obtained by the miniemulsification/solvent evaporation technique evaluating the influence of time and ultrasound application, polystyrene concentration and mass of disperse phase on the nanoparticles average size and size distribution. The increase in polystyrene concentration and in the amount of disperse phase led to an increase in the nanoparticles average size. In all experimental conditions stable miniemulsions were obtained and the nanoparticles size distributions were sharp and monodisperse.