Preparation and Characterization of Golden-Colored Pigments Based on Silver Coated with Metal Oxides
The present study aimed at the development of new artificial golden-colored pigments which are thermally stable up to 900 oC and can be used for coloring ceramics wares. Silver was used as a base material with bright metallic luster. Silver with the larger lamellar structure was indispensable to maintain the metallic luster, and it was successfully obtained by the heat-treatment of as-obtained silver powder at 200-400 oC in air and subsequently dry ball-milling at 300 rpm for 1 h. The surface of the lamellar-structured silver was coated with small particles of hydroxides, oxyhydroxides and oxides of Fe, Co, Ni, Ce and Pr. Appearance of golden color depended on the combination of metal species and heat-treatment temperature, and CeO2-coated silver gave golden color after calcination at 800 and 900 oC. The golden color of CeO2-coated silver could be controlled by the loading amount and particle size of CeO2 for color tone and relative area of naked surface of Ag for luster.
Alan K.T. Lau, J. Lu, Vijay K. Varadan, F.K. Chang, J.P. Tu and P.M. Lam
Y. Tateishi et al., "Preparation and Characterization of Golden-Colored Pigments Based on Silver Coated with Metal Oxides", Advanced Materials Research, Vols. 47-50, pp. 1462-1465, 2008