Abstract:
PROBLEM TO BE SOLVED: To provide cerium dioxide nanoparticles CeMOincluding at least one transition metal (M) and a method for preparing such particles.SOLUTION: In a process for forming cerium dioxide nanoparticles including at least one transition metal (M), a product flow including transition metal-containing cerium dioxide nanoparticles CeMO(x bears a value of approximately 0.3 to approximately 0.8) is generated by using a suspension of cerium hydroxide nanoparticles prepared by mechanically shearing an aqueous admixture including an oxidant at an amount effective for oxidizing trivalent cerium ions into tetravalent cerium ions. The nanoparticles thus obtained have a cubic fluorite-type structure, an average rheological diameter of approximately 1 to approximately 10 nm, and a geometric diameter of less than approximately 4 nm. A particle dispersion system within a non-polar medium can be prepared by using transition metal-containing crystalline cerium dioxide nanoparticles.
Abstract:
A method for forming a structured doped cerium oxide nanoparticle including the steps of forming a first aqueous cerium(lll) reaction mixture, with optional metal/s other than cerium, a base, and a stabilizer; introducing an oxidant to singly oxidize cerium (III), followed by thermal formation of a doped cerium oxide nanoparticle core; then providing a second reaction mixture of one or more metal ions other than cerium, and optionally cerium (III) ions and sufficient cerium (III) oxidant, followed by thermally converting the mixture into a shell around the doped cerium oxide nanoparticle core, wherein the ratio of metal ions in the core differs from the ratio of metal ions in the shell. The disclosed structured doped cerium oxide nanoparticle may exhibit cubic fluorite crystal structure and possess a diameter in the range 1 nm-20 nm. A dispersion of the developed nanoparticle may be used as a fuel additive.
Abstract:
Un proceso para hacer nanopartículas de dióxido de cerio que contienen al menos un material de transición (M) que comprende (a) proporcionar una mezcla de reacción acuosa que contiene una fuente de ión ceroso, una fuente de uno o más iones metálicos de transición (M), una fuente de ión de hidróxido, al menos un estabilizador de nanopartículas, y un oxidante a una temperatura inicial en un rango de alrededor de 200C alrededor de 950C; (b) cortar mecánicamente la mezcla y provocar que pase a través de una pantalla perforada, formando así una suspensión homogéneamente distribuída de nanopartículas de hidróxido de cerio; y (c) proporcionar condiciones de temperatura efectivas para lograr la oxidación de ión ceroso a ión cérico, formando así una corriente de producto que contiene nanopartículas de dióxido de cerio que contienen metal de transición, Ce1-xMxO2, en donde "x" tiene un valor de alrededor de 0.3 a alrededor de 0.8. Las nanopartículas así obtenidas, tienen una estructura de fluorita cúbica, una media de diámetro hidrodinámico en un rango de alrededor de 1 nm a alrededor de 10nm, y un diámetro geométrico menor a alrededor de 4 nm. Las nanopartículas cristalinas de dióxido de cerio que contienen metal de transición pueden usarse para preparar una dispersión de las partículas en un medio no polar.
Abstract:
A method for forming a structured doped cerium oxide nanoparticle including the steps of forming a first aqueous cerium(lll) reaction mixture, with optional metal/s other than cerium, a base, and a stabilizer; introducing an oxidant to singly oxidize cerium (III), followed by thermal formation of a doped cerium oxide nanoparticle core; then providing a second reaction mixture of one or more metal ions other than cerium, and optionally cerium (III) ions and sufficient cerium (III) oxidant, followed by thermally converting the mixture into a shell around the doped cerium oxide nanoparticle core, wherein the ratio of metal ions in the core differs from the ratio of metal ions in the shell. The disclosed structured doped cerium oxide nanoparticle may exhibit cubic fluorite crystal structure and possess a diameter in the range 1 nm-20 nm. A dispersion of the developed nanoparticle may be used as a fuel additive.
Abstract:
A process for making cerium dioxide nanoparticles containing at least one transition metal (M) utilizing a suspension of cerium hydroxide nanoparticles prepared by mechanical shearing of an aqueous mixture containing an oxidant in an amount effective to enable oxidation of cerous ion to eerie ion, thereby forming a product stream that contains transition metal-containing cerium dioxide nanoparticles, Cel-xMxO2, wherein "x" has a value from about 0.3 to about 0.8. The nanoparticles thus obtained have a cubic fluorite structure, a mean hydrodynamic diameter in the range of about 1 nm to about 10 nm, and a geometric diameter of less than about 4 run. The transition metal-containing crystalline cerium dioxide nanoparticles can be used to prepare a dispersion of the particles in a nonpolar medium.
Abstract:
A process for making cerium dioxide nanoparticles containing at least one transition metal (M) utilizing a suspension of cerium hydroxide nanoparticles prepared by mechanical shearing of an aqueous mixture containing an oxidant in an amount effective to enable oxidation of cerous ion to eerie ion, thereby forming a product stream that contains transition metal-containing cerium dioxide nanoparticles, Cel-xMxO2, wherein "x" has a value from about 0.3 to about 0.8. The nanoparticles thus obtained have a cubic fluorite structure, a mean hydrodynamic diameter in the range of about 1 nm to about 10 nm, and a geometric diameter of less than about 4 run. The transition metal-containing crystalline cerium dioxide nanoparticles can be used to prepare a dispersion of the particles in a nonpolar medium.
Abstract:
A method for forming a structured doped cerium oxide nanoparticle including the steps of forming a first aqueous cerium(lll) reaction mixture, with optional metal/s other than cerium, a base, and a stabilizer; introducing an oxidant to singly oxidize cerium (III), followed by thermal formation of a doped cerium oxide nanoparticle core; then providing a second reaction mixture of one or more metal ions other than cerium, and optionally cerium (III) ions and sufficient cerium (III) oxidant, followed by thermally converting the mixture into a shell around the doped cerium oxide nanoparticle core, wherein the ratio of metal ions in the core differs from the ratio of metal ions in the shell. The disclosed structured doped cerium oxide nanoparticle may exhibit cubic fluorite crystal structure and possess a diameter in the range 1 nm-20 nm. A dispersion of the developed nanoparticle may be used as a fuel additive.