Solvent-free atom transfer radical polymerization in the synthesis of Fe2O3 @ polystyrene core-shell nanoparticles

This paper describes the use of solvent-free atom transfer radical polymerization (ATRP) in the synthesis of Fe2O3@ polystyrene (PS) core-shell nanoparticles. In this approach, oleic acid stabilized Fe2O3 nanoparticles were ligand exchanged with 2-bromo-2-methylpropionic acid (Br-MPA), the initiator for ATRP. These Fe2O3 nanoparticles become soluble in styrene and can be used as macroinitiators for solvent-free ATRP. The synthesized core-shell nanoparticles were characterized by transmission electron microscopy (TEM), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), ultraviolet-visible (UV-vis) spectroscopy, and Fourier transform-infrared (FT-IR) spectroscopy. Well-defined Fe2O3@PS core-shell nanoparticles were obtained. The glassy transition temperature of PS was studied using DSC, and the molecular weight of PS was characterized by GPC. The unique aspects of this solvent-free ATRP in the synthesis of well-defined polymer-coated nanoparticles will be discussed.