Rational Design of sub-100 nm Polystyrene Particles With a Low Coefficient of Variation in Size

In this Phase I SBIR program, Tetramer Technologies will develop new, commercially attractive, highly monodisperse polystyrene latex standards in a variety of sizes (i.e. 30 nm to 100 nm) via emulsion polymerization processes that employ a surfactant and that are surfactant-free. Surfactant free emulsions will be stabilized through the use of ionic comonomers in the emulsion polymerization. The focus of the study will be to elucidate the inter-relation of processing parameters on the resulting particle size and coefficient of variation of the size. Specifically, once 100 nm particles with a coefficient of variation of 2% has been achieved (duplicating NIST SRM 1963a), the ratios of reagents, stirring time, and rate of reagent addition will be translated to generating particles with a size of 30 nm with a coefficient of variation 2% or less. Sizing measurements will be performed with a variety of tools including, both scanning electron microscopy and transmission electron microscopy, dynamic light scattering, and atomic force microscopy (AFM) to asses the products of the research. In addition, the cross-referencing of the techniques with one another will used to establish effective metrological practices for sizing the particles.