Preparation Of Materials For Electrophoretic Display And Electrophoretic Display Prototype

Electrophoretic displays, owing to advantages of both electronic displays and paper, have attracted a great deal of academic and commercial interests during the past ten years. They have attributes of good brightness and contrast, wide viewing angles, state bistability, low power consumption, and low cost when compared to LCDs. Nevertheless, many problems should be solved and advanced materials should be synthesized to realize the application with excellent performance.The paper first describes the preparation and characterization of a novel type of submicron SiO2-and-Al2O3-coated-TiO2 particle encapsulated by polystyrene via radical polymerization. SiO2-and-Al2O3-coated-TiO2 particle was modified by 3-(trimethoxysilyl)propylmethacrylate (MPS) coupling agent, followed by free radical copolymerization of styrene with the methacrylate group of MPS at the particle surface. The inorganic particle/polystyrene core-shell composites were characterized by means of FTIR spectroscopy, transmission electron microscopy (TEM), elemental analysis, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), and contact angle measurement, etc.. TEM and FTIR investigation provided direct and clear evidence for the presence of polystyrene shell on Si02-and-Al2O3-coated-TiO2 core particles, and TGA showed quantitative evidence of the presence of polystyrene shell on SiO2-and-Al2O3-coated-TiO2 core particles. Contact angle measurement revealed that the surface behavior of polymer/TiO2 particles had been changed to hydrophobic. It was demonstrated that polystyrene shell was chemically bonded to inorganic core surface, leading to more stable core-shell microspheres.Polystyrene/TiO2 nanocomposite particles were also synthesized in high yield by in-situ polymerizing styrene in the presence of MPS modified nano TiO2 in ethanol media. Polystyrene/TiO2 nanocomposite particles were characterized by FTIR spectroscopy, elemental analysis, GPC, and TGA methods, which indicates thatpolystyrene shell was chemically bonded to nano TiO2 core surface with a high coating efficiency.Submicron SiO2/Al2O3 coated TiO2 and nano TiO2 particles encapsulated by polybutene-succinimide pentamine and acrylic copolymers via self-assembly were achieved, respectively. Both FTIR and TGA investigations on the composites provided evidence for the presence of polymer shell on TiO2 particles. Anchoring groups adsorbed onto the surface of T1O2 particles via acid-base interaction and polymer/Ti02 composites become charged polymeric chains, providing the steric stabilization barrier around the pigment particle.Zeta potential and mobility of polymer coated TiO2 particles in non-aqueous medium were measured by Malvern Zeta sizer. It was demonstrated that polymer coated particles in non-aqueous medium were charged and can migrate under the influence of electric field. Dispersion stability depends not only on the density matching between polymer/TiO2 particles and solvent, but also on the steric stabilization. Compatibility enhanced chains of polymer/TiO2 composites extend into the good solvent medium and interact positively with the binder molecules and the solvent. Their main action is to induce the steric stabilization mechanism, which prevents the penetration of the chains of neighbouring polymer/TiO2 composites and subsequently mutual agglomeration.Stable, uniform, and spherical microcapsules were prepared from gelatin and a hydrolyzed copolymer of styrene and maleic anhydride (SMA) by complex coacervation. The gelatin/SMA microcapsules were characterized in terms of microstructure, morphologies, thermal stability, and release behavior by scanning electron microscopy (SEM), optical microscopy, and thermogravimetric analysis (TGA). It was demonstrated that the membranes of the microcapsules were formed from nano sized coacervate droplets resulting from gelatin and hydrolyzed SMA, which leads to a compact membrane structure. Microcapsules with elastic, non-permeable, optical transparent etc will enhance the performance of electrophoreticdisplays. Microcapsules...