Deposition of colored inorganic coating layers on lamellar sericite surface and the pigmentary performances

The inorganic composite pigments, Fe2O3/sericite, Bi2O3/sericite, and CoAl2O4/sericite, were prepared by the homogeneous hydrolysis of metal salts, such as FeCl3, Bi(NO3)3, and Co(NO3)2/Al(NO3)3. The deposition of the inorganic coating layers on sericite surfaces was explored by X-ray diffraction, scanning electron microscopy, Fourier transform infrared, and X-ray photoelectron spectroscopy. The inorganic coating layers were uniformly and tightly anchored at sericite surfaces via chemical bonding at the interface between the coating layer and the sericite substrate. The pigmentary performances of the inorganic composite pigments were analyzed by CIE, indicating that red, yellow, and blue colored pigments were achieved by coating Fe2O3, Bi2O3, and CoAl2O4 on sericite surfaces, respectively. The pigmentary performances of the inorganic composite pigments were significantly affected by the morphology and thickness of inorganic coating layers.