Encapsulation of organic yellow pigment particles via miniemulsion polymerisation procedure and their application in electrophoretic displays

Abstract

Pigment yellow 13/polystyrene (PY13/PS) composite particles were prepared using a miniemulsion polymerisation procedure. PY13 was suspended into the monomer phase styrene. The resultant oil suspension was added to deionised water with emulsifier sodium dodecyl benzene sulphonate (SDBS) and converted into stable miniemulsion. The miniemulsion was then polymerised using initiator Potassium peroxydisulphate (KPS). The Fourier transform infrared spectroscopy and transmission electron microscopy showed that the pigments were encapsulated by polystyrene (PS); the scanning electron microscopy indicated that the composite particles have spherical morphology and smooth surface. The particle size analysis suggested that the size distribution can be very narrow by changing the concentration of SDBS and styrene. The modified particles were used as electrophoretic particles in electrophoretic fluid with stabilizer CH-5 and charge control additive T151, and the yellow–white dual colour electrophoretic display cells were successfully made.