Microspheres of metal oxides and methods
AssigneeRegents of the University of Minnesota
InventorsPeter W. Carr, Alon V. McCormick, Bingwen Yan, Clayton V. McNeff, Fang Chen
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Abstract
Metal oxide microspheres, particularly zirconia microspheres, produced by a method of hydrolysis of metal alkoxides in alcohol solutions in the presence of an organic acid or salt thereof with washing step or addition of a surfactant.
Claims65
A method of preparing metal oxide microspheres, the method comprising:
- combining a metal alkoxide, water, an organic acid or salt thereof in an organic solvent to form a reaction mixture;
- allowing microspheres to form in the reaction mixture;
- removing the microspheres from the reaction mixture, wherein the microspheres have a reactive gel thereon;
- and
- washing the microspheres to remove at least a portion of the reactive gel.
A method of preparing substantially nonporous, metal oxide microspheres, the method comprising:
- combining a metal alkoxide, water, a C6-C30 carboxylic acid in an alcohol to form a reaction mixture;
- agitating the reaction mixture to produce microspheres;
- allowing the microspheres to age;
- removing the microspheres from the reaction mixture, wherein the microspheres have a reactive gel thereon;
- washing the microspheres to remove the reactive gel;
- and
- heating the washed microspheres under conditions and for a time to form substantially nonporous microspheres.
A method of preparing metal oxide microspheres, the method comprising:
- combining a metal alkoxide, water, an organic acid or salt thereof in an organic solvent to form a reaction mixture;
- allowing microspheres to form in the reaction mixture;
- adding a surfactant to the reaction mixture;
- and
- removing the microspheres from the reaction mixture.
A sample of as-produced, substantially nonporous, metal oxide microspheres having an average particle diameter of about 0.1 micron to about 10 microns with a standard deviation of no more than about 30 percent of the mean.
53 The stationary phase material of claim 52 wherein the metal oxide is selected from the group consisting of zirconia, titania, hafnia, alumina, niobia, yttria, magnesia, and mixtures thereof.
Dependencies are inferred from the claim text.