Surfactant-Assisted Hydrothermal Synthesis of Water-Dispersible Hafnium Oxide Nanoparticles in Highly Alkaline Media

Hafnium oxide nanoparticles were synthesized via a short-duration (10 min) hydrothermal reaction. The reaction was found to produce three differently shaped nanoparticles: flower-like nanostructures (20 nm diameter), polycrystalline nanoagglomerates (25 nm diameter), and water-dispersible single nanoparticles (4 nm diameter). The mechanisms by which these different shapes form were then investigated by examining the effects of precursor alkalinity and the presence of an organic capping agent. The synthesized water-dispersible nanoparticles showed a very high affinity for water-soluble polymers, thus demonstrating their potential for fabrication of transparent nanocomposite films.