Preparation and characterization of inorganic colored coating layers on lamellar mica-titania substrate

摘要

The inorganic colored composite pigments, such as Fe_2O_(3-), Bi_4Ti_3O_(12)-, and CoAl_2O_4-coated mica-titania composites, were prepared by hydrolysis of FeCl_3, Bi(NO_3)_3, and Co(NO_3)_2/Al(NO_3)_3 in the presence of mica-titania substrate and calcination at different temperatures. The inorganic coating layers on mica-titania substrate surfaces were explored by X-ray diffraction, scanning electron microscopy, Fourier transform infrared, and X-ray photoelectron spectroscopy. Dense and uniform Fe_2O_3 coating layers were formed on the surfaces of mica-titania substrates. At lower Bi2O_3 loading, Bi_4Ti_3O_(12) nanoparticles were formed on the surfaces of mica-titania substrates. But at higher Bi2O_3 loading, Bi_4Ti_3O_(12) nanosheets were formed and perpendicularly oriented to the substrate surfaces. CoAl_2O_4 nanosheets were formed on the mica-titania substrates and perpendicularly oriented to the substrate surfaces. The pigmentary performances of the inorganic composite pigments were analyzed by CIE, indicating that red, yellow, and blue colored pigments were achieved by coating Fe2O_3, Bi_4Ti_3O_(12), and CoAl_2O_4 on mica-titania substrate surfaces, respectively. The pigmentary performances of the inorganic composite pigments were significantly affected by the morphology and loading of inorganic coating layers.