Patent ID: 8409544

Claim:
A process of preparing magnetite nanoparticles, characterized in that it includes the following steps: 1) preparing a ferric salt mixed system, wherein a soluble ferric salt is dissolved in glycol at ambient temperature, and then urea and polyethylene glycol are added and mixed uniformly to obtain the ferric salt mixed system, the mass ratio of glycol to the ferric salt being 15:1 to 60:1, glycol to urea being 20:1 to 100:1, and glycol to polyethylene glycol being 20:1 to 100:1; 2) reacting, wherein the ferric salt mixed system is transferred into a reaction autoclave, sealed and placed into a heating device to react at a temperature of 200 to 300° C. for 8 to 72 hours; and 3) washing, wherein after the reaction system is naturally cooled down to ambient temperature, the product is taken out, and washed with anhydrous ethanol and water in turn to obtain the magnetite nanoparticles.