Encapsulated quantum dots in porous particles
The invention provides a process for the production of a (particulate) luminescent material comprising particles, especially substantially spherical particles, having a porous inorganic material core with pores, especially macro pores, which are at least partly filled with a polymeric material with luminescent quantum dots embedded therein, wherein the process comprises (i) impregnating the particles of a particulate porous inorganic material with pores with a first liquid (“ink”) comprising the luminescent quantum dots and a curable or polymerizable precursor of the polymeric material, to provide pores that are at least partly filled with said luminescent quantum dots and curable or polymerizable precursor; and (ii) curing or polymerizing the curable or polymerizable precursor within pores of the porous material, as well as a product obtainable thereby.
1. A process for the production of a luminescent material, the luminescent material comprising particles having a porous inorganic material core with pores which are at least partly filled with a polymeric material with luminescent quantum dots embedded therein, the process comprising:
impregnating the particles of the particulate porous inorganic material with a first liquid comprising the luminescent quantum dots and a curable or polymerizable precursor of the polymeric material, to provide pores that are at least partly filled with said luminescent quantum dots and curable or polymerizable precursor; and curing or polymerizing the curable or polymerizable precursor within pores of the porous material.
2. The process according to claim 1 , wherein before curing or polymerizing but after impregnating the particles, the impregnated particles and first liquid are separated.
3. The process according to claim 1 , wherein the pores of the porous inorganic material are hydrophobized.
4. The process according to claim 1 , wherein the particles have particle sizes in the range of 1-500 μm.
5. The process according to claim 1 , wherein the process further comprises applying an encapsulation to the particles obtained after curing or polymerizing.
6. The process according to claim 5 , wherein the process further comprises providing the encapsulation by at least partly coating the particles with an inorganic coating selected from the group consisting of a silicon containing oxide, an aluminum containing oxide, a zirconium containing oxide, a glass, a titanium containing oxide, a hafnium containing oxide and an yttrium containing oxide.
7. The process according to claim 5 , wherein the process further comprises providing the encapsulation by multi-layer coating the particles, wherein the thus obtained multi-layer coating comprises an organic polymer coating and an inorganic coating, or at least two coatings selected from the group consisting of a silicon containing oxide, an aluminum containing oxide, a zirconium containing oxide, a glass, a titanium containing oxide, a hafnium containing oxide and an yttrium containing oxide.
8. The process according to claim 5 , wherein the process further comprises providing the encapsulation by at least partly coating the particles by atomic layer deposition.
9. The process according to claim 5 , wherein the process further comprises one or more of providing the encapsulation by embedding the particles in a light transmissive solid matrix, or providing the encapsulation by at least partly coating the particles and subsequently embedding the particles in a light transmissive solid matrix.
10. The process according to claim 1 , wherein the porous inorganic material comprises porous silica.
11. The process according to claim 1 , wherein the porous inorganic material comprises porous alumina.
12. The process according to claim 1 , wherein the porous inorganic material comprises porous glass.
13. The process according to claim 1 , wherein the porous inorganic material comprises porous zirconia.
14. The process according to claim 1 , wherein the porous inorganic material comprises porous titania.
15. The process according to claim 1 , wherein the pores have mean pore sizes in the range of 0.1-10 μm.
16. The process according to claim 1 , wherein the precursor comprises a curable acrylate.
17. The process according to claim 1 , wherein the precursor comprises silicone.