The Preparation Of Toluidine Red Electrophoretic Particles And The Research Of Microcup Electrophoretic Display Device

Recently, Electrophoretic Display acting as a new display technology was given wide attention. The display was the movement of the particles in electric field which required excellent dispersion and stability in a fluid medium with higher charge. It made an important significance to prepare and modify electrophoretic particles, select electrophoresis dispersed medium and research microcup display devices.In this text we explore and study the preparation and surface modification of the superfine Toluidine Red particles. Firstly the particles were prepared by recrystalling method in order to reduce the mean particle size and then modified the particles to increase its charge and stabilization. The produced particles was characterized by Fourier transform infrared spectrophotometry (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), Zeta potential test, size distribution analysis and electrophoretic experiment. Secondly, in order to improve the compatibility between the organic liquid medium and the electrophoretic particles, the dispersed medium was selected. Lastly, the manufacture of microcup display device was researched. The main contents are as follows:Firstly, the preparation and modification of ultra-fine Toluidine Red particles were done by antisolvent recrystal method and in situ modified method. Through the study of solvent type, stirring speed, surface active agent type, reaction temperature and so on, the best experimental conditions were got:solvent for concentrated sulfuric acid, anti-solvent for deionized water, reaction temperature was 20℃, stirring speed was about 900rpm. When surface active agent was alkyl hydroximic acid (AHOA) and the concentration was 3.75g·L-1, the modification result was best. Under this condition, the prepared particles diameter were about 80nm and showed narrow distribution, roundness and good distribution. The sedimentation rate was 15.4% for 200h when TR particles dispersed in C2C14. Electrophoretic response time was 2.0s and Zeta potential was 25.4mV.Secondly, the selection of electrophoresis dispersed medium was researched. Compared with different mixed organic solvent, the best result was that C2Cl4/cyclohexane acting as dispersed medium. Particles existed steadily in the C2Cl4/cyclohexane medium for 200h and the sedimentation rate was only 4.76%. But, mixed dispersed medium made an important influence to the particles feature and size, the particles diameter reached to 2μm around and glomerated seriously.Lastly, the manufacture and encapsulation of microcup display devices were researched. The corrasion of microcup was made by photoetching method. The thickness of microcup could be reached to 30μm using the positivity and thick photoresist. The prepared microcup display device could disperse the particles and increase the response capability basically. The electrophoretic particles could move when added 30V voltage between microcup display device and brushing screen time was about 5s.