Preparation of polystyrene particles containing poly(ethylene glycol) groups and their surface charge characterization in dielectric medium

Abstract

Polystyrene particles (PS) with poly(ethylene glycol) units on surface were formed by an emulsifier-free emulsion polymerization using styrene, poly(ethylene glycol) methacrylate (PEG-MMA) or poly(ethylene glycol) dimethacrylate (PEG-diMMA) at pH 7, and followed by freeze-drying to give the corresponding powders. The structures of PS particles were confirmed by FT-IR spectroscopy, and the particle size and distribution the PS particle were observed by scanning electron microscopy and particle analyzer. Monodisperse polymer particles were obtained at a concentration of PEG-MMA 2similar to5 mol% or PEG-diMMA 1 mol% relative to styrene. The highest zeta potential of polymer surface was measured to be 183 mV at a polymer of PEG-MMA 5 mol%, which was measured in dielectric medium by means of ELS-8000 dynamic light scattering.