Preparation and characterization of high contrast electrophoretic display suspension containing charged black-and-white nanoparticles

Abstract

In this study, TiO2 nanoparticles with sizes ranging from 300- 400nm were modified by two-step dispersion polymerization using poly (styrene-co-divinylbenzene)-methyl methacrylate [P (St-co-DVB)-MMA] as shell. And core, carbon black (CB) nanoparticles with size ranging from 30-50nm and polymer shell poly (methacrylic acid) [PMAA] were prepared by grafting polymerization, too. Modified nanoparticles were characterized on structure, mean particle size and size distribution, morphology with FT-IR, TEM, and image analyzer. Furthermore, modified TiO 2 as negatively charged electrophoretic particles and CB nanoparticles as cationically charged electrophoretic particles were homodispersed in tetrachloroethylene (TCE) to make the electrophoretic display suspension with Span-80 as dispersant and OLOA 1200 as charge control agent. The zeta potential and mobility of white (TiO2) and black (CB) charged particles were measured to be -61.4 mV, 9.50×10-6 cm 2 /V s and 12.8 mV, 1.98×10-6 cm 2 /V s by using an electrophoresis test device, respectively. Final, the electric response behaviors of the electrophoretic display suspension were studied under electrostatic field. The black-and-white particles moved quickly and reversibly inside ITO electrodes while the electric field alternated.