Patent 8647510 was granted and assigned to 3M on February, 2014 by the United States Patent and Trademark Office.
A method of preparing zirconia-containing nanoparticles and a method of preparing a composite material that includes the zirconia-containing nanoparticles are provided. A method of treating a zirconium carboxylate salt solution to remove alkali metal ions and alkaline earth ions is provided. The treated solution can be used as a feedstock to prepare the zirconia-containing nanoparticles. Additionally, a continuous hydrothermal reactor system is provided that can be used, for example, to prepare the zirconia-containing nanoparticles.