Fluidized Bed Preparation Of Composite Particles

In order to modify the surface properties of the particles, composite particles are prepared by the process of Chemical Vapor Deposition (CVD) in a fluidized bed reactor. Silica gel particles loaded TiO₂ were obtained by using TiCU as precursor. The relation between the deposition weight of TiO₂ and time was studied. The photocatalytic performance of composite particles was also evaluated by the degradation of oxalic acid under the ultraviolet radiation. SEM and EDS were used to characterize the surface structural properties of composite particles. It was found that the deposited TiO₂ in nanometer and micrometer range, which was on the surface of Silica gel particles, was uniform. The deposition weight of TiO₂ increased as the reaction time prolonged, but a maximum existed in the process. The photocatalytic performance of composite particles was excellent. By using Ti(OC₄H₇)₄ and Si(OC₂H₅)₄ as precursors, silica particles coated by TiO₂ and SiO₂ film were prepared, respectively. But only fewer composite particles were obtained due to the little deposition quantity of TiO₂ and SiO₂. Aluminum particles coated by TiO₂ were prepared by using TiCU as precursor. The effect of the pretreatment of Aluminum particles by H₂O and C₄H₇OH on the composite particles was studied, respectively. SEM and EDS analysis indicated that aluminum particles had coated by TiO₂ successfully. The size of TiO₂ on the surface of modified aluminum particles was decreased and the coating was more uniform.