| Inorganic nanofilm composites have potentially commercial applications due to their distinguished electric, magnetic, and optical properties in integrated circuits, sensors, optical filters, cosmetics, plastics, inks, and coatings. Inorganic nanofilm composites have attracted more researcher's attention. In this thesis, the structures of inorganic nanofilms on lamellar sericite surfaces were analyzed by using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy(XPS). The morphologies of the inorganic nanofilms were characterized by using scan electron micrographs (SEM). The evolution mechanisms of the inorganic nanofilms on lamellar sericite surface were investigated. The optical properties of lamellar sericite inorganic nanofilm composites were analyzed by CIE optical system. And the structure-activity relationship between the structures of lamellar sericite inorganic nanofilm composites and their optical properties was discussed.Anatase titania/serisite nanocomposites were prepared by liquid chemical deposition method in the presence of La3+. While in the absence of La3+ cations, anatase TiO2 coating layers anchored at the sericite surface via Ti-O-Si and Ti-O-Al bonding. When La3+ cations were present in the reaction solution, the small-sized TiO2 nanoparticles formed since that the formation of Ti-O-La bonds at the TiO2 surfaces inhibited the TiO2 crystal growth. La3+ cations anchored at the sericite surface by formation of La-O-Al and La-O-Si bonds and the aluminum sites on the sericite surface were dominantly occupied by La3+ TiO2 coating layers subsequently anchored at the sericite surface via Ti-O-Si bonds, giving a higher dispersibility of the resultant TiO2 nanoparticles. The light scattering indexes of the TiO2/sericite nanocomposites prepared in the presence of La3+ were higher than that prepared in the absence of La3+Rutile TiO2/sericite nanocomposites were prepared by the chemical deposition method starting from lamellar sericite and TiCl4 in the presence of crystal modifier. The presence of Sn4+induced the phase transformation of amorphous to rutile TiO2. It can be explained as being due to that at a high calcination temperature, Sn4+ ions can replace lattice Ti4+ ions, subsequently, rutile SnO2 crystals evolved. Rutile TiO2 and SnO2 both have tetragonal crystal structure with similar lattice constants. Therefore, SnO2 crystals act as seeds for the phase transformation of amorphous to rutile TiO2. XPS analysis shows that Sn4+ cations anchored at the sericite surfaces by formation of Al-O-Sn and Si-O-Sn bonds, and the aluminum and silicon sites on the sericite surfaces were dominantly occupied by Sn4+ cations. TiO2 coating layers were subsequently anchored at the sericite surfaces via Ti-O-Sn bonds. The TiO2/sericite nanocomposites had higher light scattering indexes than the naked sericite powders. The brightness, whiteness, and light scattering index of the rutile TiO2/sericite nanocomposites were slightly higher than those of the anatase TiO2/sericite nanocomposites.The inorganic nanocomposites, 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 inorganic nanofilms of Fe2O3 uniformly and tightly anchored at sericite surfaces via Fe-O-Si and Fe-O-Al bonds. Bi2O3 and CoAl2O4 nanosheets perpendicularly anchored at sericite surfaces to form nanofilms via Bi-O-Si, Bi-O-Al; Co-O-Si, Co-O-Al bonds. The optical performances of the colored inorganic nanocomposites were significantly affected by the morphology and thickness of inorganic coating films.The inorganic nanocomposites, such as Fe2O3, Bi4Ti3O12, and CoAl2O4/sericite-titania nanocomposites, were prepared by liquid chemical deposition method and using FeCl3, Bi(NO3)3, and Co(NO3)2/Al(NO3)3 as precursors. The inorganic nanofilms of Fe2O3 uniformly and tightly anchored at sericite-titania surfaces via Fe-O-Ti bonds. Bi4Ti3O12, and CoAl2O4 nanosheets perpendicularly anchored at sericite-titania surfaces to form nanofilms via Bi-O-Ti; Co-O-Ti, Al-O-Ti bonds. The optical performances of the colored inorganic nanocomposites were significantly affected by the morphology and thickness of inorganic coating films.The present results show that the surface structure, morphology, and optical property of sericite-based inorganic nanocomposites are related to the physicochemical property of the inorganic films. The present work has theoretical guidance meaning for constructing inorganic nanofilms on the surface of lamellar sericite. Sericite-based inorganic nanocomposites are potential candidates for organic pigments with poor weatherability, which usually cause high pollution during their production processes. |
