Method for synthesis of colloidal nanoparticles
View Patent ↗A method for synthesis of high quality colloidal nanoparticles using comprises a high heating rate process. Irradiation of single mode, high power, microwave is a particularly well suited technique to realize high quality semiconductor nanoparticles. The use of microwave radiation effectively automates the synthesis, and more importantly, permits the use of a continuous flow microwave reactor for commercial preparation of the high quality colloidal nanoparticles.
1. A method for synthesizing nanoparticles, comprising:
preparing one or more constituent elements at a temperature below 100° C., wherein the constituent elements include ionic liquids that enhance formation rates of the nanoparticles;
heating the prepared constituent elements using microwave irradiation to an elevated temperature at a rate of 30° C./min or higher, in order to create a reaction mixture;
stabilizing the reaction mixture at the elevated temperature; and
cooling the stabilized reaction mixture to a reduced temperature at a rate of 80° C./min or higher, so that the nanoparticles are synthesized.
2. The method of claim 1 , wherein a dielectric constant of a main constituent element is 20 or lower.
3. The method of claim 1 , wherein the constituent elements are prepared at or near a room temperature below 100° C.
4. The method of claim 1 , wherein the heating step is performed using the microwave irradiation and one or more other heat sources.
5. The method of claim 1 , wherein the prepared constituent elements are selectively heated via absorption of the microwave irradiation to the elevated temperature at a rate of 34° C./min or higher.
6. The method of claim 1 , wherein the stabilized reaction mixture is cooled to the reduced temperature at a rate of 90° C./min or higher.
7. The method of claim 1 , wherein the nanoparticles' growth is controlled by adjustment of kinetic and thermodynamic barriers by power, temperature, time or additive.
8. The method of claim 1 , wherein the heating and cooling steps maintain an average diameter of 0.5 to 100 nm for the nanoparticles with a standard deviation of +/−20%.