US 9,669,375 B2 · Method for production of stable cerium oxide organic colloids

Abstract

An improved process for producing substantially non-polar doped or un-doped cerium oxide nanoparticle dispersions is disclosed. The cerium-containing oxide nanoparticles of an aqueous colloid are transferred to a substantially non-polar liquid comprising one or more amphiphilic materials, one or more low-polarity solvents, and one or more glycol ether promoter materials. The transfer is achieved by mixing the aqueous and substantially non-polar materials, forming an emulsion, followed by a phase separation into a remnant polar solution phase and a substantially non-polar organic colloid phase. The organic colloid phase is then collected. The promoter functions to speed the transfer of nanoparticles to the low-polarity phase. The promoter accelerates the phase separation, and also provides improved colloidal stability of the final substantially non-polar colloidal dispersion. Importantly, the glycol ether promoter reduces the temperature necessary to achieve the phase separation, while providing high extraction yield of nanoparticles into the low-polarity organic phase.

Claims12

Dependent claims

A process for preparing a colloidal dispersion, comprising:

(a) preparing an aqueous colloidal dispersion of cerium-containing oxide nanoparticles;
(b) adding a substantially non-polar solvent and an amphiphilic material;
(c) mixing the liquid mixture of step (b) to form an emulsion;
(d) heating the emulsion to a temperature ranging from about 20° C. to less than 60° C. for a predetermined time, whereafter the emulsion separates into a substantially non-polar colloidal phase and a remnant aqueous phase;
and,
(e) collecting the separated substantially nonpolar colloidal dispersion of cerium-containing oxide nanoparticles
wherein the process further comprises adding at least one glycol ether prior to step (e) in step (b), after step (c), or during step (d), and adding at least one glycol ether to the collected substantially non-polar colloidal dispersion of cerium-containing oxide nanoparticles after step (e),
wherein said glycol ether is selected from the group consisting of diethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol methyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol rnonopropyl ether, and combinations thereof.

5 more elements

Dependencies are inferred from the claim text.

Method for production of stable cerium oxide organic colloids

Life of this patent

Method for production of stable cerium oxide organic colloids

Life of this patent

Abstract

Claims12