Preparation And Characterization Of Dual Colored Microcapsule Type Electrophoretic Display Prototype In Isopar M System

The use of Isopar M as a liquid suspending fluid for electrophoretic display wasstudied. A series of blue-white, red-white and yellow-white dual-particle microcapsuletype electrophoretic display device were prepared and studied in this paper. Thecomponents of blue, yellow, red and white electrophoretic fluid were investigated.Urea-formaldehyde microcapsules prepared by in situ polymerization andgelatin-arabic gum microcapsules prepared by complex coacervation method werestudied. Microcapsule type electrophoretic display device could display high-contrastimage under low voltage changes.The formulations of electrophoretic fluid were investigated by orthogonalexperiment and condition method. The dispersion stability and chargeability ofpigments suspended in isopar M were investigated. For a simple electrophoreticdispaly device, the contrast ratio of blue-white, red-white and yellow-whiteelectrophoretic fluid reached2.92,2.72and1.33, respectively.Microcapsules were prepared through complex coacervation method, withgelatin and arabic gum as wall material, and dual-particle Isopar M fluid as corematerial. The factors affecting the shape and properties of microcapsules werediscussed, such as the mass ratio of wall/core material, the concentration of gelatinsolution, resorcinol solution and SDS solution and the pH value. It was found that theprepared microcapsules possess smooth surface and sphericity, high mechanicalstrength. The encapsulation efficiency was15.50%. The microcapsules weresuccessfully applied to electrophoretic display, and the contrast ratio of blue-white,red-white and yellow-white microcapsules reached1.96,1.72and1.30, respectively.Microcapsules were prepared through in situ polymerization, with urea andformaldehyde as wall material, and dual-particle Isopar M fluid as core material. Thefactors affecting the shape and properties of microcapsules were discussed, such asthe mass ratio of wall/core material, the stirring rate, the concentration of SDSsolution and glutaraldehyde solution and the pH value. It was found that the preparedmicrocapsules possess smooth surface and sphericity, superior transparence, highmechanical strength,15.50%encapsulation efficiency. The microcapsules weresuccessfully applied to electrophoretic display, and the contrast ratio of blue-white, red-white and yellow-white microcapsules reached1.67,1.62and1.22, respectively.Compared with tetrachloroethylene system microcapsule type electrophoreticdisplay device, Isopar M system possesses a longer working time.