Y. Kim, R. Yu, J. Yun, J.H. Pee
Korea Institute of Ceramic Engineering and Technology, KR
Keywords: pigment, chemcal stability, ceramic coating
Summary:
Generally, nano-sized pigments have reduced their original properties at high temperature and acidic/basic condition. To retain and enhance the properties of ceramic pigments, we adopted core-shell approach. Typically, we selected the silica (SiO2), tin (IV) oxide (SnO2) and titanium oxide (TiO2) as shell materials for minimizing their oxidation and aggregation of nanoparticles due to its transparency in the visible range. This work describes a means of improving the chemical stability of ceramic coated pigment such as α-Fe2O3 (red) and CoAl2O4 (blue). In addition, we have studied the chemical stability of SiO2 or SnO2 coated CoAl2O4. To determine the stability of the coated pigments and their colloidal solutions under acidic and basic conditions, pigment solutions with various pH values were prepared and monitored over two week. We evaluated experimental tests of chemical stability to the CIE Lab △E calculation. Details of the phase structure and optical properties of core-shell structures were characterized by UV-vis, TEM (transmission electron microscopy), CIE Lab color and XRD (powder X-ray diffraction).