Patent ID: 8846785

Claim:
A method for manufacturing spherical, monodispersed core-shell type ceria-polymer hybrid nanoparticles having a coefficient of variation of diameter of less than 0.10 comprising: a mixing step which comprises mixing a cerium salt and a polymer in a high-boiling-point organic solvent to obtain a mixture, a heating and reflux step which comprises heating and refluxing the mixture at a temperature of 110° C. or more to thereby generate a boiling phenomenon, and a rapid cooling step which comprises rapidly cooling the mixture after the heating and reflux step, wherein the cooling rate down to 110° C. in the rapid cooling step is at least 0.5° C./sec, and wherein the cerium salt is cerium nitrate hydrate, the polymer is polyvinyl pyrrolidone, hydroxypropyl cellulose, or hydroxypropyl methylcellulose, and the high-boiling-point organic solvent is ethylene glycol, diethylene glycol glycelin, or propylene glycol, and wherein the spherical, monodispersed core-shell type ceria-polymer hybrid nanoparticles have structure composed of a core part comprising secondary particles of spherical aggregation of primary cerium oxide particles and a layer of polymer forming a shell part on the surface of the secondary particles, and the size of the secondary particles is 30-200 nm, the size of the primary particles is 1-10 nm, the percentage of shell part is 15-25% by weight, the density is 4-5 g/cm 3 , and the specific surface area is 10-200 m 2 /g.