White light quantum dot complex particle and process for preparing same

1. A white light quantum dot complex particle, comprising a seed particle in a core, and a first shell layer, a second shell layer and a third shell layer wrapped around the seed particle in order,

wherein in the first shell layer, the second shell layer and the third shell layer are respectively one of a red light quantum dot layer, a green light quantum dot layer and a blue light quantum dot layer, and are different from one another;

wherein the seed particle has a particle size of 10-500 nm, and a range of a thickness of the first shell layer, the second shell layer and the third shell layer is 5-50 nm;

a ratio of amounts of the red light, green light and blue light quantum dots in the complex particle is 0.5˜0.8: 1:1.2˜1.5;

the red light quantum dots comprise CdSe quantum dots with an emission wavelength of 600˜700 nm; the green light quantum dots comprise CdSe quantum dots with an emission wavelength of 490˜570 nm; and the blue light quantum dots comprise CdSe quantum dots with an emission wavelength of 430˜460 nm.

2. The white light quantum dot complex particle according to claim 1 , wherein the seed particle is a silicon dioxide nanoparticle, an Al 2 O 3 nanoparticle or a ZnO nanoparticle.

3. The white light quantum dot complex particle according to claim 1 , wherein the seed particle is a silicon dioxide nanoparticle having its surface modified with polymerizable double bonds.

4. The white light quantum dot complex particle according to claim 1 , wherein the seed particle has a particle size of 20-50 nm; and a range of a thickness of the first shell layer, the second shell layer and the third shell layer is 10-20 nm.

5. The white light quantum dot complex particle according to claim 1 , wherein the ratio of amount of the red light, green light and blue light quantum dots in the complex particle is 0.65˜0.74:1:1.25˜1.35.

6. The white light quantum dot complex particle according to claim 1 , wherein the red light quantum dots comprise CdSe quantum dots with an emission wavelength of 613 nm; the green light quantum dots comprise CdSe quantum dots with an emission wavelength of 555 nm; and the blue light quantum dots comprise CdSe quantum dots with an emission wavelength of 452 nm.

7. A process for preparing a white light quantum dot complex particle according to claim 1 , comprising:

dispersing a seed particle in water to obtain a seed suspension;

mixing red light quantum dots, green light quantum dots and blue light quantum dots with a monomer, an initiator, a surfactant and water, respectively, for emulsification to obtain three emulsion systems respectively, which are designated as the emulsion system A, the emulsion system B and the emulsion system C, respectively;

heating the seed suspension to 60-90° C., to which the emulsion system A is dripped, and then reacting with constant temperature for 2-10 h; then dripping the emulsion system B into the seed suspension, and then reacting with constant temperature for 2-10 h; then dripping the emulsion system C into the seed suspension, and then reacting with constant temperature for 2-10 h, to form the first shell layer, second shell layer and third shell layer in order; and

washing the product after conclusion of the reaction to obtain the white light quantum dot complex particle.

8. The preparative process according to claim 7 , wherein a weight percent concentration of the seed particle in the seed suspension is 5-8%.

9. The preparative process according to claim 8 , wherein the weight percent concentration of the seed particle in the seed suspension is 5.5-7%.

10. The preparative process according to claim 7 , wherein the monomer is at least one of the alkenes having a total of 4-24 carbon atoms, and a weight percentage of the monomer in each emulsion system is 0.1-20%.

11. The preparative process according to claim 10 , wherein the monomer is styrene, and the weight percentage of the monomer in each emulsion system is 0.2-10%.

12. The preparative process according to claim 7 , wherein the initiator is at least one of potassium persulfate, ammonium persulfate, sodium persulfate or hydrogen peroxide, and a weight percentage of the initiator is 0.1%-8% by weight of the monomer.

13. The preparative process according to claim 12 , wherein the initiator is at least one of potassium persulfate, ammonium persulfate, sodium persulfate or hydrogen peroxide, and a weight percentage of the initiator is 0.5%-4% by weight of the monomer.

14. The preparative process according to claim 7 , wherein the surfactant is at least one of sodium dodecyl sulfate, sodium dodecyl sulfonate or cetyltrimethylammonium bromide, and a weight percentage of the surfactant in each emulsion system is 0.1-10%.

15. The preparative process according to claim 14 , wherein the surfactant is sodium dodecyl sulfate, sodium dodecyl sulfonate or cetyltrimethylammonium bromide, and a weight percentage of the surfactant in each emulsion system is 0.5-5%.

16. The preparative process according to claim 7 , wherein a weight percentage of the red light quantum dots, the blue light quantum dots and the green light quantum dots in each emulsion system is 0.08-12%.

17. The preparative process according to claim 7 , wherein a weight ratio between the seed particle and the green light quantum dots is 10-12.5:1.

18. The preparative process according to claim 7 , wherein a rate for dripping each emulsion system is 0.01-5ml/min.

19. The preparative process according to claim 18 , wherein a rate for dripping each emulsion system is 0.1-0.5ml/min.