Preparation of Electronic Ink using TiO2 Particles Dispersed in Low Dielectric Solvent

摘要

An electrophoretic display using TiO2 particles is the most promising candidate because it offers various advantages such as ink-on-paper appearance, good contrast ratio, wide viewing angle, image stability in the off-state and extremely low power consumption. The core technology of elcctrophoretic display is dispersion controlling of TiO2 nano particles in nonaqueous solution. To prepare an ink for electronic paper using T1O2 nano particles, cyclohexane with low dielectric constant and transparency, polyethylene for producing polymer coating layer which reduces apparent density of TiO2, and T1O2 nano powders were intermixed using planetary-mill. The zeta-potential value of TiO2 particles in cyclohexane was measured about -40 mV, but was measured over -110 mV by dispersant attached to polyethylene-coated TiO2 surface. Prepared electronic ink was filled in cross patterned micro-wall with 200 pm in width and 40 m in height on ITO glass designed by photolithography. The response time of electronic paper evaluated by mobility of TiO2 particle between micro-walls was measured 0.067sec, but the drift velocity from reflectance wave form during reverse turn of electronic ink was measured 0.07cm/sec.