Synthesis and characterization of well dispersed electronic ink particles for electronic paper

1-Phenyl-3-naphthyl-5-((dimethylamino)phenyl)-2-pyrazoline nanoparticles with different sizes from 190 to 40 nm were prepared by the reprecipitation method and polymerized with methyl methacrylate and ethylene glycol dimethacrylate and controlled by changing the concentration of surfactants. We found that pyrazoline nanoparticles possess a special size dependence in their optical properties. As the nanoparticle size decreased, the absorption and emission peak of pyrazoline nanoparticles were observed to shift to the high-energy side due to the aggregate formation and increased intermolecular interaction in the nanoparticles. The electronic ink particles of pyrazoline organic nanoparticles were successfully prepared by dispersion polymerization in aqueous alcohol medium for full color electronic paper, which is expected to substitute for the future display. In order to improve their mobility, the surfactant was added as a charge control additive. The electrophoretic mobility of the resulting electronic inks was −x-7.5 to −3.6 × 10
⁻⁵
cm
²
/V·s in the presence of surfactants.