Gelatin/carboxymethylcellulose/dioctyl sulfosuccinate sodium microcapsule by complex coacervation and its application for electrophoretic display

We have described the microcapsules containing electrophoretic fluid as core material, prepared from gelatin, sodium carboxymethylcellulose (NaCMC) and dioctyl sulfosuccinate sodium (DSS) by complex coacervation method. The gelatin/NaCMC/DSS microcapsules are characterized by optical microscopy (OM), scanning electron microscopy (SEM), particle size analysis and thermogravimetric analysis (TGA). It is found that DSS plays an important role in the formation of the microcapsule wall and the concentration of DSS deeply affects the yield of microcapsules by enhancing the interaction between gelatin and NaCMC. The microcapsules prepared with DSS content of 0.6 mM show compact capsule wall which endows the capsules with good barrier property and high thermal stability. These microcapsules are applied successfully to prepare a 4-in. clock display panel controlled by single-chip microprocessor (SCM) operated at a low direct current (DC) voltage of 3 V, demonstrating that these microcapsules are potential for the applications in the area of electrophoretic displays.