Synthesis of colored calcium carbonate and its color

The synthesis of calcium carbonate (CaCO3) was conducted under the presence of food dye. A food dye was added into Ca(OH)2 suspension with citric acid aqueous solution, and CaCO3 was synthesized by reacting prepared Ca(OH)2 suspension with CO2 gas. Sunset yellow FCF and brilliant blue FCF were selected for food coloring. All products were calcite which is a stable phase. When the amount of citric acid aqueous solution added was 08 cm3, the crystallinity of calcite decreased with increasing the amount added by X-ray diffraction (XRD) patterns. Also, the crystal shapes using scanning electron microscope were observed. At the amount of citric acid aqueous solution 0, 5, and 8 cm3, the shapes of obtained calcite were fine calcite particles, elliptical particles, dumbbell-shaped, and rod-shaped particles. Various forms of calcite were synthesized by changing the amount of citric acid aqueous solution. In addition, the obtained samples were colored bright orange and blue. These products were called colored CaCO3 and colored by adsorption of dye on CaCO3 particles and incorporating dyes into CaCO3 crystals. It was possible to obtain various shapes CaCO3 colored by synthesizing under the presence of dye in the Ca(OH)2CO2H2O reaction system.