title: Dispersion characteristics of TiO2 particles coated with the SiO2 nano-film by atomic layer deposition.
abstract: Deposition of SiO2 nanofilm on TiO2 particles using atomic layer deposition method is reported. The SiO2 film was prepared at the room temperature using the chemicals Si(OC2H5)4, C2H5N and H2O as precursor, catalyst and reactant gas, respectively. The thickness, composition and uniformity of the SiO2 coating on TiO2 surface were characterized by FESEM, HRTEM, EDS and XPS measurements. In HRTEM analysis, the growth rate was about 0.33 angstroms/cycle. EDS and XPS analysis showed the surface composition of TiO2 nanoparticles was silicon oxide. Zeta potential, particle size distribution and sedimentation test results indicated that dispersibility of coated nanoparticles was higher than that of uncoated nanoparticles because of the electrostatic repulsion between the SiO2-coated layers on the surface of TiO2 nanoparticles. These results suggested that the SiO2 coating could modify the surface characteristics of the TiO2 nanoparticles and improve the dispersibility of the TiO2 primary nanoparticles.
authors.affiliation: School of Advanced Materials and Systems Engineering, Kumoh National Institute of Technology, Gumi Gyungbuk 730-701, Republic of Korea.
authors.forename: Hyug Jong
authors.initials: HJ
authors.lastname: Kim
authors.forename: In Gu
authors.initials: IG
authors.lastname: Kang
authors.forename: Doe Hyoung
authors.initials: DH
authors.lastname: Kim
authors.forename: Byung Ho
authors.initials: BH
authors.lastname: Choi