Chemical Physics Letters, Vol.699, 55-63, 2018
Insights into effects and mechanism of pre-dispersant on surface morphologies of silica or alumina coated rutile TiO2 particles
Silica and alumina coated rutile TiO2 samples with various surface morphologies were fabricated using four different pre-dispersants. Using sodium silicate nonahydrate (SSNH) as pre-dispersant, the received sample displayed the best acidic stability. The addition of SSNH could induce layer-by-layer growth of hydrous silica via enhancing the dispersion of hydrous silica nucleus and accelerating the dehydration condensation rate of silica film. Alumina coated rutile TiO2 sample obtained by polyethyleneglycol 1000 (PEG) presented the highest dispersion stability. The existence of PEG can induce the formation of fibrous hydrous alumina film, which would increase the steric hindrance and the promotion of dispersion stability. (C) 2018 Elsevier B.V. All rights reserved.
Keywords:Rutile TiO2;Pre-dispersant;Silica and alumina films;Surface morphology;Film forming kinetics