Preparation of Melamine-Formaldehyde Resin Microcapsules Used for Electrophoretic Display
The microcapsules used for electrophoretic display were prepared by in-situ polymerization. The core material contained electrophoretic particles (phthalocyanine blue and TiO2) and tetrachloroethylene (TCE), and the wall material were made of melamine-formaldehyde resin. The effects of preparation conditions, such as the concentration of surfactant, the ratio of core material to wall material, the pH values were all experimentally investigated. Moreover, titanium dioxide (TiO2) particles were modified with 3-(trimethoxysilyl)propyl methacrylate (TPM) in order to obtain a lipophilic surface. Furthermore, the modified TiO2was coated with polystyrene (PS) for improving the density mismatch between TiO2particles and TCE. The core material of phthalocyanine blue was modified with octadecylamine to improve its dispersibility in TCE. The morphology of microcapsules was observed by optical microscope. The coated TiO2particles were characterized by scanning electron microscope and thermogravimetry analysis. The modified TiO2particles and phthalocyanine blue were determined by FTIR spectrometry.