High charged red pigment nanoparticles for electrophoretic displays

Organic pigment permanent red F2R nanoparticles were prepared via surface modification to improve the surface charge and dispersion ability in organic medium.Their large surface chargeability is confirmed by ζ-potential value of −49.8 mV. The prepared particles exhibited average size of 105 nm and showed very narrow distribution with polydispersity index of 0.068. The sedimentation ratio of the prepared particles in tetrachloroethylene was less than 5% within 12 days. The electrophoretic inks consisting of the prepared red particles with white particles as contrast showed good electrophoretic display, its refresh time was 200 ms.

► Pigment permanent red F2R nanoparticles were prepared via surface modification.
► Average size of the prepared particles was 105 nm with very narrow distribution.
► Surface charge and dispersion ability in organic medium were investigated.
► The prepared red particles showed good electrophoretic display.