Abstract: A process for making cerium-containing oxide nanoparticles includes providing an aqueous reaction mixture containing a source of cerous ion, optionally a source of one or more metal ions (M) other than cerium, a source of hydroxide ion, at least one monoether carboxylic acid nanoparticle stabilizer wherein the molar ratio of said monoether carboxylic acid nanoparticle stabilizers to total metal ions is greater than 0.2, and an oxidant at an initial temperature in the range of about 20° C. to about 95° C. Temperature conditions are provided effective to enable oxidation of cerous ion to ceric ion, thereby forming a product dispersion of cerium-containing oxide nanoparticles, optionally containing one or more metal ions (M), Ce1-xMxO2-?, wherein “x” has a value from about 0.0 to about 0.95. The nanoparticles may have a mean hydrodynamic diameter from about 1 nm to about 50 nm, and a geometric diameter of less than about 45 nm.

Abstract: A process for replacing the continuous phase of a nanoparticle dispersion with a less polar phase, includes filtering the dispersion through a semi-permeable membrane filter to remove the continuous phase, and introducing a less polar phase.

Abstract: A method of improving the efficiency of a diesel engine provided with a source of diesel fuel includes the steps of: a) adding to the diesel fuel a reverse-micellar composition having an aqueous first disperse phase that includes a free radical initiator and a first continuous phase that includes a first hydrocarbon liquid, a first surfactant, and optionally a co-surfactant, thereby producing a modified diesel fuel, and b) operating the engine, thereby combusting the modified diesel fuel. The efficiency of a diesel engine provided with a source of diesel fuel and a source of lubricating oil can also be improved by modifying the lubricating oil by the addition of a stabilized nanoparticulate composition of cerium dioxide. The efficiency of a diesel engine can also be improved by adding to the diesel fuel a reverse-micellar composition that includes an aqueous disperse phase containing boric acid or a borate salt.

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: 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: 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.

Abstract: A method of making a structured, doped, cerium oxide nanoparticle includes (a) forming a first reaction mixture including cerium(III), an optional metal ion other than cerium, a base, a stabilizer, and a solvent, (b) contacting the first reaction mixture with an oxidant, (c) forming a cerium oxide nanoparticle core by heating the product of step (b), (d) forming a second reaction mixture by combining with the first reaction mixture one or more metal ions other than cerium, and an optional additional quantity of cerium(III), and (e) forming a shell surrounding the core of cerium oxide by heating the second reaction mixture to produce a product dispersion of structured cerium oxide nanoparticles.

Abstract: A method of improving the efficiency of a diesel engine provided with a source of diesel fuel includes the steps of: a) adding to the diesel fuel a reverse-micellar composition having an aqueous first disperse phase that includes a free radical initiator and a first continuous phase that includes a first hydrocarbon liquid, a first surfactant, and optionally a co-surfactant, thereby producing a modified diesel fuel; and b) operating the engine, thereby combusting the modified diesel fuel. The efficiency of a diesel engine provided with a source of diesel fuel and a source of lubricating oil can also be improved by modifying the lubricating oil by the addition of a stabilized nanoparticulate composition of cerium dioxide. The efficiency of a diesel engine can also be improved by adding to the diesel fuel a reverse-micellar composition that includes an aqueous disperse phase containing boric acid or a borate salt.

Abstract: A method of making cerium dioxide nanoparticles includes: a) providing an aqueous reaction mixture having a source of cerous ion, a source of hydroxide ion, a nanoparticle stabilizer, and an oxidant at an initial temperature no higher than about 20° C.; b) mechanically shearing the mixture and causing it to pass through a perforated screen, thereby forming a suspension of cerium hydroxide nanoparticles; and c) raising the initial temperature to achieve oxidation of cerous ion to eerie ion and thereby form cerium dioxide nanoparticles having a mean diameter in the range of about 1 nm to about 15 nm. The cerium dioxide nanoparticles may be formed in a continuous process.

Abstract: A process for making cerium-containing oxide nanoparticles includes providing an aqueous reaction mixture containing a source of cerous ion, optionally a source of one or more metal ions (M) other than cerium, a source of hydroxide ion, at least one monoether carboxylic acid nanoparticle stabilizer wherein the molar ratio of said monoether carboxylic acid nanoparticle stabilizers to total metal ions is greater than 0.2, and an oxidant at an initial temperature in the range of about 20° C. to about 95° C. Temperature conditions are provided effective to enable oxidation of cerous ion to ceric ion, thereby forming a product dispersion of cerium-containing oxide nanoparticles, optionally containing one or more metal ions (M), Ce1-xMxO2-?, wherein “x” has a value from about 0.0 to about 0.95. The nanoparticles may have a mean hydrodynamic diameter from about 1 nm to about 50 nm, and a geometric diameter of less than about 45 nm.

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 steps 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.

Abstract: A method of Improving the efficiency of a diesel engine provided with a source of diesel fuel includes the steps of: a) adding to the diesel fuel a reverse-micellar composition having an aqueous first disperse phase that includes a free radical initiator and a first continuous phase that includes a first hydrocarbon liquid, a first surfactant, and optionally a co-surfactant, thereby producing a modified diesel fuel; and b) operating the engine, thereby combusting the modified diesel fuel. The efficiency of a diesel engine provided with a source of diesel fuel and a source of lubricating oil can also be improved by modifying the lubricating oil by the addition of a stabilized nanoparticulate composition of cerium dioxide. The efficiency of a diesel engine can also be improved by adding to the diesel fuel a reverse-micellar composition that includes an aqueous disperse phase containing boric acid or a borate salt.