Magnetic core—ceramic shell nanocrystals and manufacturing method thereof
AssigneeKorea University Foundation
InventorsYoung Keun Kim, Hong Ling Liu, Jun Hua Wu, Ji Hyun Min, You Song Kim
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Abstract
Provided are magnetic core-ceramic shell (e.g., magnetite (Fe3O4) core-calcium phosphate (Ca3(PO4)2) shell) nanocrystals with high crystallization degree, uniform size, and high chemical stability and a method for synthesizing the same. A core-shell structure is synthesized in a process of forming magnetite seeds corresponding to cores by the reduction of magnetite precursors and then, sequentially, coating the magnetite with Ca3(PO4)2 by the reduction of Ca3(PO4)2 precursors.
Claims6
A method for manufacturing bifunctional magnetic core-ceramic shell nanocrystals in a sequential process, the method comprising:
- mixing magnetic core material precursors with a reducing agent for the core material precursors;
- mixing the magnetic core material precursors and the reducing agent with an organic solvent for the magnetic core material precursors and the reducing agent and with a surfactant Poly(Ethylene Oxide)-Poly(Propylene Oxide)-Poly(Ethylene Oxide) (PEO-PPO-PEO) and forming a first mixture solution;
- heating the first mixture solution to a first temperature above 200° C. and maintaining the first mixture solution for a first time;
- cooling the first mixture solution to room temperature and forming magnetic core materials;
- mixing the magnetic core materials with ceramic shell material precursors and a reducing agent for the ceramic shell material precursors and forming a second mixture solution;
- heating the second mixture solution to a second temperature and maintaining the second mixture solution for a second time;
- and
- cooling the second mixture solution to room temperature and coating the magnetic core materials with the ceramic shell materials,
- wherein the core is Fe3O4 and the shell is Ca3(PO4)2.
A method for manufacturing bifunctional magnetic core-ceramic shell nanocrystals in a sequential process, the method comprising:
- mixing Fe3O4 precursor, FeIII(acac)3, with a reducing agent for the Fe3O4 precursor;
- mixing the Fe3O4 precursor and the reducing agent with dioctyl ether, an organic solvent, and with a surfactant Poly(Ethylene Oxide)-Poly(Propylene Oxide)-Poly(Ethylene Oxide) (PEO-PPO-PEO) and forming a first mixture solution;
- heating the first mixture solution to about 300° C. and maintaining the first mixture solution for 1 to 2 hours;
- cooling the first mixture solution to room temperature and forming Fe3O4 cores;
- mixing the Fe3O4 cores with calcium acetate, ammonium phosphate, and reducing agents for the Fe3O4 cores, calcium acetate and ammonium phosphate and forming a second mixture solution;
- heating the second mixture solution to 80° C. and maintaining the second mixture solution for 30 minutes;
- and
- cooling the second mixture solution to room temperature and coating the Fe3O4 cores with the ceramic shells, wherein the shells are Ca3(PO4)2.
Dependencies are inferred from the claim text.