Partially crosslinked P(SMA-DMA-St) copolymer in situ modified RGB tricolor pigment particles for chromatic electrophoretic display

RGB tricolor organic pigments were in situ modified by stearyl methacrylate-2-(dimethylamino)ethyl methacrylate-styrene random copolymer [P(SMA-DMA-St)] through solution polymerization. The modified particles were charged in tetrachloroethylene (TCE) with the aid of suitable charge control agent. The structure and electrophoretic property of ink particles were characterized by FTIR, TEM, PALS, et al. P(SMA-DMA-St) modification decreased the particles size and enhanced the suspending stability of the pigments in tetrachloroethylene due to the repulsive forces among the treated pigment particles resulting from the extending polyacrylate chain in the media. Partial crosslinking the P(SMA-DMA-St) on the pigment surface with ethylene glycol dimethacrylate (EGDMA) helped to increase the Zeta potential and electrophoresis mobility of RGB electrophoretic particles. The maximum values of the Zeta potential for red, green, and blue electrophoretic particles reached −36.2, −57.7, and −42.7 mV, respectively. The obtained RGB electrophoretic particles could be applied in the color/white dual-particle electronic ink together with charged TiO 2 to show vivid color and white images under a DC electric field. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013