Synthesis and Study on Effect of Ceramic Matrix on Nanocomposite Hematite Pigment by Wet Chemical Methode

The hematite as a natural and non toxic red pigment has been known since prehistoric times but colour shade of hematite becomes unstable with high temperature and needs to be protected with a suitable composite matrix. In this research stability of hematite has been increased by encapsulation of its nano particles in well known ceramic matrix with high termal-chemical stability. Synthesis of this kind of pigment regard to importance of in situ formation of two phases of composite must be wet chemical routes. At first nano hematite particles were synthesized with same mole ratio into silica، alumina and zircon matrix separately and binary. Then synthesized gels were calcinated and sintered in the furnace at 1250°C. In order to comparision of stability and quality of product، some studies on the nanocapsulate pigments have been done such as X-ray diffraction، colorimeter، scanning and transmission electron microscopy. The synthesized hematites have spherical morphology and particle size about 10-20 nanometer. The best inclusion system was prepared in zircon casings but The best red shade was obtained in alumina system. J. Color Sci. Tech. 6 (2012), 27-33© Institute for Color Science and Technology.