NOVEL CERAMIC PIGMENTS: SYNTHESIS, CHARACTERIZATION, ABSORPTION AND COLOUR PROPERTIES

Novel ceramic pigments containing B, Al, Cu, Ti, and Si oxides were prepared via the sol–gel method. Dark green ceramic pigments were obtained by varying the B/Cu molar ratio while maintaining constant ratios of other metal oxides. The structural and morphological characteristics of the ceramic pigments were investigated using XRD, FTIR, SEM and EDX analyses. UV–vis analyses were conducted in three different solvents to examine the effect of the solvent on the light absorption properties of the pigments. The CIELAB colorimetric system was employed to quantify the colour of the synthesized ceramic pigments. Variations in the metal ratios and the different molecular arrangements of all metal oxides within the pigment structure led to changes in the colour parameters (L*, a*, b*). In the visible-light region, the absorption band of the ceramic pigments shifted away from the centre of the green region toward the blue region, which is attributed to the acidic nature of the prepared solutions (pH = 1). The increase in proton concentration in the solution caused the absorption bands to shift toward shorter wavelengths.