Miniemulsion Polymerization Based on Low Energy Emulsification with Preservation of Initial Droplet Identity

A study was conducted to demonstrate the first synthesis of polymeric nanoparticles employing a low energy miniemulsification procedure. Styrene was polymerized at 70 °C in aqueous miniemulsion initiated by azobis(isobutyronitrile) (AIBN) employing the anionic surfactant disulfonated alkyl diphenyloxide sodium salt (Dowfax 8390). The system offered excellent control over monomer droplet and particle size, with a unique degree of preservation of initial droplet identity in addition to the benefits of a low energy process. Miniemulsions stabilized by ionic surfactants were obtained by dilution of a bicontinuous or an oil-in-water (O/W) microemulsion with excess water in the low energy emulsion inversion point (EIP) method. Three different miniemulsions were also prepared by dilution of the O/W microemulsion precursor at the arrow corresponding to 57.8 wt % water.