Synthesis and Characterization of Surface Modification of TiO2 Nanoparticles for Electrophoretic Display
TiO2 and carbon black inorganic pigments having opposite charges have been typically used for white and black image in the electronic ink display technique, respectively. However, since TiO2 has a relatively high density, the density mismatch between nanoparticles and the dielectric medium causes severe sedimentation problem in the suspended media. In order to change its surface from hydrophilic to hydrophobic and lower its density, TiO2 was grafted by γ-Methacryloxypropyl trimethoxy silane (KH570), and then coated with poly(methyl methacrylate) (PMMA) via a dispersion polymerization method prior to being used for an electronic ink material. In order to improve their mobility, a charge control agent was also added to the suspension of synthesized nanoparticles in the dielectric medium. The KH570-grafted TiO2 nanoparticles and the TiO2/KH570/PMMA nanoparticles were characterized by fourier transform-infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). Density of TiO2/KH570/PMMA nanoparticles was found to be decreased. Thermal properties of the composite particles were analyzed by thermogravimetric analysis (TGA).
Qunjie Xu, Honghua Ge and Junxi Zhang
Y. Bai et al., "Synthesis and Characterization of Surface Modification of TiO2 Nanoparticles for Electrophoretic Display", Advanced Materials Research, Vols. 361-363, pp. 1960-1964, 2012