Preparation of water-dispersible TiO2 nanoparticles

Water-dispersible TiO₂ nanoparticles with narrow size distribution and good crystallinity were synthesised in a solvothermal process using lactic acid as the capping agent. X-ray diffraction, transmission electron microscopy and nitrogen adsorption-desorption isotherm were used to characterise the products. Meanwhile, the dispersion behaviour of the as-prepared TiO₂ nanoparticles was investigated. The as-prepared powder can be easily redispersed in water to form a stable solution-like suspension with a concentration of 60 mg·ml^-1. Moreover, the dispersion mechanism was also preliminarily discussed, suggesting that the excellent dispersibility of the as-prepared TiO₂ nanoparticles is probably because of electrostatic repulsion from lactic acid molecules covalently linked to TiO₂ nanoparticles.