Preparation of Quantum Dot Beads Having a Silyl Surface Shell

• US 20140264193A1
• Filed: 03/13/2014
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Nanoco Technologies Limited (Nanoco Group Plc)
• Original Assignee: Nanoco Technologies Limited (Nanoco Group Plc)
• Inventors: Naasani, Imad, Daniels, Siobhan
• Granted Patent: US 9,783,733 B2
• Time in Patent Office: Days
• US Class Current: 252/519.31
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C09K 11/02 Use of particular materials as binders, particle coatings or suspension media therefor
• CPC Class Codes: C09K 11/70 containing phosphorus
• CPC Class Codes: Y10S 977/779 Possessing nanosized particles, powders, flakes, or clusters other than simple atomic impurity doping

Abstract

Quantum dots (QDs) are encapsulated within microbeads having a silyl surface shell. The microbeads are prepared by copolymerizing unsaturated resins and an unsaturated organosilane in the presence of QDs. During the copolymerization, the unsaturated resin and the organosilane phase separate, forming beads having a silyl surface shell surrounding an essentially unsilylated interior. The QDs are encapsulated within the interior. The silyl shell provides a barrier against oxygen and other contaminants diffusing into the bead and reacting with the QDs.

Claims

1. A method for preparing quantum dot-containing microbeads, the method comprising:

preparing a mixture comprising quantum dots (QDs), organosilane monomer, acrylic monomer, crosslinking agent, and initiator, and

polymerizing the mixture such that the organosilane monomers phase separate from the acrylic monomers, yielding polymer microbeads having a silyl surface shell.

2. The method of claim 1, wherein the mixture further comprises polyvinyl alcohol.

3. The method of claim 1, wherein the acrylic monomer is lauryl methacrylate.

4. The method of claim 1, wherein the organosilane monomer is 3-(trimethoxysilyl) propyl methacrylate.

5. The method of claim 1, wherein the cross linking agent is trimethylol propane trimethacrylate.

6. The method of claim 1, wherein the QDs comprise a core semiconductor material comprising indium and phosphorus.

7. A method as recited in 2 wherein the ratio of acrylic monomer to organosilane monomer is about 1:

1 to about 4;

1.

8. A microbead comprising:

an polymer interior;

a silyl surface shell disposed upon the polymer interior; and

quantum dots encapsulated within the polymer interior.

9. The microbead of claim 8, wherein the polymer interior comprises acrylic polymer.

10. The microbead of claim 9, wherein the acrylic polymer is lauryl methacrylate.

11. The microbead of claim 8, wherein the microbead has a diameter of about 0.2 to about 1000 microns.

12. The microbead of claim 8, wherein the microbead has a diameter of about 2 to about 100 microns.

13. The microbead of claim 8, wherein the silyl surface has a thickness of about 0.01 to about 300 microns.

14. The microbead of claim 8, wherein the silyl surface has a thickness of about 0.1 to about 40 microns.

15. The microbead of claim 8, wherein the quantum dots are substantially free of heavy metals.

16. The microbead of claim 8, wherein the quantum dots are substantially free of carbon.

17. The microbead of claim 8, wherein the quantum dots each comprise a core comprising indium and phosphorus and a shell comprising zinc and sulfur.