Flame spray pyrolysis synthesis of ceramic nanopigments CoCr2O4: The effect of key variables

Spinel structure CoCr2O4 was synthesized by the non-conventional method flame spray pyrolysis (FSP) and the traditional route solid state reaction, where the optical properties were evaluated. The influences of FSP conditions as pressure of dispersion air and ceramic load of the solution over optical properties were evaluated using a 22 full factorial design with one replica. The final products were applied in ceramic glazes to evaluate pigmenting power. Powders were characterized by X ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis-NIR spectroscopy and Colorimetry. Results show that ceramic pigments obtained by FSP have highest percent reflectance and brightness than solid state reaction powders; nevertheless, both pigments are adequate to ceramic application. Besides, experiments showed that ceramic load of the starting solution have a strong influence over particle properties.