Microencapsulation and characterization of poly(vinyl alcohol)-coated titanium dioxide particles for electrophoretic display

Abstract Titanium dioxide (TiO 2 ) particles were coated by poly(vinyl alcohol) (PVA) via a simple method of coacervation without a conventionally practiced polymerization step. Transmission electron microscopy (TEM) images clearly showed that the successful coating was achieved on the surface of TiO 2 particles. The average thickness of PVA coating layer was about 1.07 μm and the amount of coated PVA was 1.40 wt.% relative to TiO 2 . The existence of PVA layer on TiO 2 was also verified from FT-IR spectra. The PVA-coated TiO 2 particles were further microencapsulated via coacervation of gelatin and gum Arabic. Regarding the performance of the resulting microcapsules, the resulting PVA-coated TiO 2 particles showed both a good electrophoretic movement and a good bistability in the microcapsules. Therefore, these microcapsules embedding PVA-coated TiO 2 particles can be used as a good candidate for the electrophoretic displays.