Small-molecule in situ stabilization of TiO2 nanoparticles for the facile preparation of stable colloidal dispersions

Whilst numerous strategies for the controlled synthesis of TiO2 nanoparticles of different sizes and shapes have evolved within the last years, the preparation of stable colloidal dispersions from these nanoparticle products remains a challenge that needs to be overcome in order to realize targeted applications such as optically transparent functional thin films. Complementary to the mechanical dispersion of agglomerated nanopowders is the chemical stabilization strategy, which is most effective using in situ stabilizers that are present in the reaction medium from the first synthesis stages and can lead to optimum stabilization, often even to completely nonagglomerated nanoparticles. On the other hand, these stabilizers can interfere with the particle formation process, resulting in changed morphology and sometimes decreased crystallinity of the product as undesired side effects. Therefore, an understanding of the interactions and effects of in situ stabilizers is key to the development of fabrication routes to nanoparticle dispersions of highest stability for future applications. In this study, we show that TiO2 nanoparticle dispersions with high solid content can be obtained utilizing the concepts of in situ stabilization along with a chemical synthesis strategy, and provide insights into the effects of different small-molecule stabilizers on the resulting product. (C) 2010 Elsevier B.V. All rights reserved.