Synthesis And Application Of Multicolor Electrophoretic Particles For Imaging Displays

At present, almost electrophoretic imaging particles were prepared with pigment and by different methods according to corresponding pigments. In this thesis, imaging particles were prepared with cross-linked polymer and pigment or dye and by simple method. For this, emulsion polymerization, precipitation polymerization and salting modification were carried out successively.In studying emulsion polymerization, it was discovered that stable latex could be prepared under non-equilibrium state, which HLB value was not matched between monomoers and surfactant. And traditional mechanism of emulsifier-free emulsion polymerization had been corrected and replenished. And many reaction conditions were applied for precipitation polymerization and modifying products prepared by precipitation polymerization.Then, precipitation polymerization was carried out smoothly by interface and dispersion. Titanium dioxide composite microsphere was prepared with 4-vinylpyridine, and the mechanism was researched. Red, green and blue microsphere was prepared with acid dyes and successively by one bath-three stages method and phase-transfering coloration. Besides,3,4,9,10-perylenetetracarboxylic acid dianhydride was grafted into polymer chains to obtain a splendid red particle.On the basis of the above mentioned, pyridyl or epoxy group on the surfaces of all particles was salted which could ionize in organic solvents.As results, zeta potential was changed with different ions on the surface of particles prepared by above methods and dispersed in electrophoretic medium, and zeta potential was controlled by adjusting amount of ion. Meanwhile, in a part, particle size could influence upon zeta potential. Response time, an electrophoresis parameter, was influenced mainly by zeta potential and concentration of electrophoretic particles in medium. In 0.2mm tiselius cell, electrophoresis was tested under 10V electric field.