Toluidine Red Nanoparticles and Their Application in Electrophoretic Display

Toluidine red pigment nanoparticles were prepared by anti-solvent precipitation and were modified by different surfactants aimed to use as the electrophoretic particles. Experimental conditions have been discussed in this paper including the effect of different surfactants, the concentration of surfactants, the reaction temperature and the agitation rate. Binary mixtures of organic solvents have been selected as suspending medium to improve the dispersion stability of the prepared particles. The produced nanoparticles have been characterized by scanning electron microscopy, laser diffractometer and electrophoretic display measuring system. The results indicated that the prepared particles modified by alkyl hydroxy oximido acid are in the average size of 80 nm with a spherical shape within narrow particle size distribution. The optimum content of AHOA, reaction temperature agitation rate are 3.75 g/L, 20 °C and 900 rpm, respectively. The prepared nanoparticles exhibit superior electrophoretic properties. Finally, the sedimentation of prepared particles dispersed into binary mixtures of tetrachloroethylene (C₂Cl₄) and cyclohexane is 4.76% for 2 months.