Abstract:

An ultrafine TiO₂ dispersion slurry was prepared using ultrafine TiO₂ as the raw material, PEG-10 polydimethylsiloxane as the dispersant, and decamethylcyclopentasiloxane as the solvent. The effects of the amount of dispersant on the stability and viscosity of the dispersion slurry were studied in detail. The results indicated that, at a solid content of 30% and a dispersant dosage of 6%, the viscosity of the dispersion slurry was only 57.20 mPa·s, which had small thixotropy and high stability and was not easy to flocculate and settle. The sun protection factor （SPF） of the dispersion slurry was 11 with the active ingredient content of 5% in vaseline. The UV protective property of the slurry was significantly improved when compared with TiO₂ powder whose SPF was merely 9. Rheological studies showed that the dispersion slurry was a pseudoplastic fluid with shear thinning characteristics. And the flow behavior could be fitted into the power law model. The effects of temperature on viscosity could be well described by the Arrhenius equation. It was found that the viscosity decreased with the increase of temperature. Moreover, the higher the solid content, the more sensitive the viscosity as changed with temperature.

Key words: TiO₂ dispersion slurry, UV protection, sun protection factor, rheology, viscosity