Abstract: Improved methods for producing colloidal dispersions of cerium-containing oxide nanoparticles in substantially non-polar solvents 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, optionally, 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.

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.

Abstract: A fuel additive composition includes: a) a reverse-micellar composition having an aqueous disperse phase that includes cerium dioxide nanoparticles in a continuous phase that includes a hydrocarbon liquid, a surfactant, and optionally a co-surfactant and b) a reverse micellar composition having an aqueous disperse phase that includes a cetane improver effective for improving engine power during fuel combustion. A method of making a cerium-containing fuel additive includes the step of: a) providing a mixture of a nonpolar solvent, a surfactant, and a co-surfactant; and b) combining the mixture with an aqueous suspension of stabilized cerium dioxide nanoparticles.