Preparation and characterization of poly(methyl methacrylate) coated TiO2 nanoparticles

Titanium dioxide (TiO2) nanoparticles were modified with poly(methyl methacrylate) (PMMA) to improve the dispersion stability of the nanoparticles in a dielectric medium and to reduce the density mismatch between TiO2 and a dielectric medium for a microcapsule-type electrophoretic display application. Nanoparticles were coated with PMMA by in situ dispersion polymerization. The PMMA-coated TiO2 nanoparticles were characterized by fourier transform-infrared spectrometrey (FT-IR), electrophoretic light scattering (ELS), and scanning electron microscopy (SEM). Density of PMMA-coated TiO2 nanoparticles was found to be dependent on the thickness of the PMMA coating on the nanoparticles. An increase of thermal stability of the PMMA layer and the contents of PMMA on the surface of the nanoparticles were measured via thermogravimetric analysis (TGA).