Deposition of thin TiO 2 films on fluorophlogopite particle surface by CVD in fluidized bed reactor to prepare silver pearlescent pigments

Two critical parameters: Glossiness and chromaticity space of pearlescent pigments were evaluated based on crystallinity and grain size. Both the roughness and the vertical distance evolution along the surface of deposited TiO 2 film are affected by the crystallinity. The optimal crystallinity of TiO 2 was deposited at the temperature of 350 °C. The TiCl 4 concentration effectively changed the grain size. However, the high flow rate of fluidizing gas and optimal gas–solid ratio (<0.11 m 3 /(kg h)) restricted the change of TiCl 4 concentrations in fluidized bed reactor. In this case, the grain size of the deposited TiO 2 film was about 55 nm. Depending on the grain size, the color of pearlescent pigments was adjusted by controlling the film thickness based on TiO 2 concentration. Finally, the silver pearlescent pigment with high glossiness was prepared by chemical vapor deposition method in a fluidized bed reactor.