Highly Stable Dispersibility in Water Induced by Surface Hydration Force of TiO₂ Nanocrystalline Mixtures During Phase Transformation

Abstract

Titania (TiO₂) nanoparticles were prepared by the alcohothermal method using tetra-n-butyl titanate [] as a precursor. The phase transformation from anatase to rutile happened when the nanoparticles were calcined at 800°C and 900°C in an oven, respectively. TiO₂ nanocrystalline mixtures had the highly stable dispersibility when they were dispersed in water medium. The zeta potentials of the different TiO₂ nanoparticles showed that the surface electrostatic forces were not crucial factors in such stable dispersibility. Other characterizations, including x-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR), indicated that the phase transformation was favor of the adsorption of water on TiO₂ surface. A visual model was presented to illustrate that the strong repulsive surface hydration force prevented TiO₂ nanoparticles from aggregation.

Keywords:

• Dispersibility
• heat treatment
• nanomaterials
• surface hydration force
• Titania

Acknowledgments

The present work was supported by the National Natural Science Foundation of China (Grant No. 20671028) and Nature Science Foundation of Hebei Province (Grant No. E2009000911).

Notes

^a Anatase (upper row), rutile (nether row).