Surface modification of organic pigment particles for microencapsulated electrophoretic displays

The surface modification of Pigment Yellow 13, Pigment Red 254 and Pigment Blue 15 to improve their electrophoretic properties in electrophoretic suspension were studied. The particle size distribution and the surface morphology of the modified pigments were determined, the presence of the functional groups on the surface of pigments was confirmed, and the dispersion stability and chargeability of pigments suspended in electrophoretic slurry were characterized. For the application of microencapsulated electrophoretic displays, the colored microcapsules containing the modified organic pigments were prepared and spread on an ITO coated conducting film. A working prototype of electrophoretic display was successfully fabricated in this approach. ► Organic pigments were used in EPDs to obtain good color saturation. ► The modified organic pigments have good dispersion stability and chargeability. ► The color-white display prototypes were successfully fabricated.