Preparation and application of black hollow carbon-doped titania composite spheres for electrophoretic displays

In this paper, hollow carbon-doped titania composite spheres were prepared through a template-assisted method. The hollow spheres were obtained via deposition of inorganic shell on the surface of polymer latex template with Ti(OBu)4 as precursor and then freeze-drying process was used to reduce breaking and fragments during calcinations. After calcinations in Ar atmosphere, carbon layer was coated onto the surface of hollow microspheres by adsorption to the resulting hollow black spheres with various crystalline structures at different calcination temperatures. The hollow spheres were characterized with scanning electron microscopy (SEM), transmission electron microscopy, energy dispersive X-ray spectrometer, thermo gravimetric analysis, Brunauer–Emmett–Teller, X-ray diffraction, ultraviolet and visible absorption and electrophoresis apparatus. The results showed that the hollow TiO2/C spheres were monodisperse and average diameters were 220 nm approximately. Furthermore, the new kind of composite material was applied to electrophoretic display as black particles. The electrophoretic mobility and zeta value in Isopar-G were −2.60e−006 cm2 V−1 s−1 and −35.31 mV respectively, which illustrated its potential application prospect in development of electrophoretic ink.