Preparation of Charged Composite Particles for Electrophoretic Display

전기영동 디스플레이용 대전 복합입자의 제조

  • Na, Hae-Jin (Department of Chemical Engineering, KyungHee University) ;
  • Baek, Jeong-Ju (Regional Innovation Center for Components and Materials for Information Display, KyungHee University) ;
  • Kim, Ji-Suk (Regional Innovation Center for Components and Materials for Information Display, KyungHee University) ;
  • Kim, Sung-Soo (Department of Chemical Engineering, KyungHee University)
  • 라해진 (경희대학교 화학공학과) ;
  • 백정주 (경희대학교, 디스플레이 부품소재 지역혁신센타) ;
  • 김지숙 (경희대학교, 디스플레이 부품소재 지역혁신센타) ;
  • 김성수 (경희대학교 화학공학과)
  • Published : 2009.07.25

Abstract

Charged organic-inorganic composite particles were prepared for the application to electrophoretic display technology such as electronic paper. $TiO_2$ and $Co_3O_4$ particles were used for core particles and were coated with poly(methyl methacrylate) by dispersion polymerization. Composite particles were endowed with charge moiety for electrophoresis; positive charge for $TiO_2$ and negative charge for $Co_3O_4$ composite particles. Scanning electron microscopic results revealed that the charged composite particles have spherical shape. Densities of the composite particles were controlled to be that of medium of electrophoresis. Density of $TiO_2$ particle changed from 4.02 to 1.44 g/$cm^3$ after the polymer coating, and that of $Co_3O_4$ particles changed from 6.11 to 1.49 g/$cm^3$. Urea, melamine, and formaldehyde were used as wall materials for capsule, and microcapsule containing black or white particles inside were prepared by in-situ polymerization. Microcapsule showed the inspection by a video microscope demonstrated the formation of uniform transparent capsules.

전자종이 등 전기영동을 이용한 디스플레이 기술에 사용하기 위한 대전 입자를 유무기 복합 형태로 제조하였다. $TiO_3$$Co_3O_4$를 core 입자로 사용하여 Poly(methyl methacrylate)를 분산 중합으로 코팅하였다. 또한, 코팅 고분자에 charge moiety를 부여하여 $TiO_2$ core 입자는 양전하의 복합입자로 $Co_3O_4$ core 입자는 음전하의 복합입자로 제조하였다. 제조된 대전입자는 중합 후 구형의 형태를 갖게 되었음을 전자현미경을 통하여 확인을 하였다. 대전 복합입자를 전기영동에 사용하기 위하여 전기영동 유체와 유사한 밀도를 갖도록 조절하였다. $TiO_2$ 입자의 밀도는 고분자 코팅 전후 4.02 g/$cm^3$에서 1.44 g/$cm^3$로 변화하였고, $Co_3O_4$ 입자의 경우 입자의 밀도가 6.11 g/$cm^3$에서 1.49 g/$cm^3$로 변화하였다. Urea, melamine, formaldehyde를 벽물질로 하여 흑백 입자를 각각 포함하는 microcapsule을 in-situ polymerization 방법으로 제조하였으며, 균일한 크기와 투명한 microcapsule이 제조되었음을 video 현미경을 통하여 확인하였다.

Keywords

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