Surface-Modified Nanoparticles
The surfaces of nanoparticles (QDs) are modified with amphiphilic macromolecules, for example, amphiphilic copolymers. The surface modification renders the QDs more compatible with oxygen-excluding matrices, such as epoxy resin, polyurethane resin, polyester resins or any hydrophilic inorganic/organic hybrid resin such as (meth)acrylate-functionalized polyhedral oligomeric silsesquioxane (POSS).
1 . A surface-modified nanoparticle comprising:
a nanoparticle having a core and an external surface;
a plurality of amphiphilic macromolecules on the external surface.
2 . The surface-modified nanoparticle recited in claim 1 wherein the amphiphilic macromolecules are adsorbed on the external surface of the nanoparticle.
3 . The surface-modified nanoparticle recited in claim 1 wherein the amphiphilic macromolecules have a first, polar portion and a second, non-polar portion.
4 . The surface-modified nanoparticle recited in claim 1 wherein the nanoparticle is a metal oxide.
5 . The surface-modified nanoparticle recited in claim 4 wherein the nanoparticle is selected from the group consisting of: iron oxides, titanium oxides, zinc oxide, zirconium oxide, and aluminum oxide.
6 . The surface-modified nanoparticle recited in claim 1 wherein the nanoparticle is a magnetic nanoparticle.
7 . The surface-modified nanoparticle recited in claim 1 wherein the nanoparticle is a gold nanoparticle.
8 . The surface-modified nanoparticle recited in claim 1 wherein the nanoparticle is a silver nanoparticle.
9 . The surface-modified nanoparticle recited in claim 1 wherein the nanoparticle comprises a luminescent semiconductor material.
10 . The surface-modified nanoparticle recited in claim 1 wherein the nanoparticle is selected from the group consisting of: CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, InP, InAs, InSb, AlP, AlS, AlAs, AlSb, GaN, GaP, GaAs, GaSb, PbS, PbSe, Si, Ge and combinations thereof.
11 . The surface-modified nanoparticle recited in claim 1 wherein the nanoparticle is a cadmium-free nanoparticle.
12 . The surface-modified nanoparticle recited in claim 1 wherein the nanoparticle is a core-shell nanoparticle wherein the core is substantially comprised of a first material and the shell is substantially comprised of a second material different from the first material.
13 . The surface-modified nanoparticle recited in claim 12 wherein the core-shell nanoparticle comprises a plurality of shells with adjacent shells substantially comprised of different materials.
14 . The surface-modified nanoparticle recited in claim 12 wherein the core-shell nanoparticle comprises a shell material selected from the group consisting of ZnS, ZnO, MgS, MgSe, MgTe and GaN.
15 . The surface-modified nanoparticle recited in claim 12 wherein the core-shell nanoparticle comprises a core comprised substantially of InP, first shell comprised substantially of ZnS, and a second shell comprised substantially of ZnO.
16 . The surface-modified nanoparticle recited in claim 1 wherein the amphiphilic macromolecules comprise a block copolymer.
17 . The surface-modified nanoparticle recited in claim 16 wherein the block copolymer comprises a first block having an affinity for the external surface of the nanoparticle.
18 . The surface-modified nanoparticle recited in claim 17 wherein the block copolymer comprises a second block that is more polar than the first block.
19 . The surface-modified nanoparticle recited in claim 17 wherein the block copolymer comprises a second block that has affinity for an epoxide resin.
20 . The surface-modified nanoparticle recited in claim 16 wherein the block copolymer comprises a first block that incorporates at least two monomers each of which including at least one atom having affinity for the nanoparticle surface.
21 . The surface-modified nanoparticle recited in claim 18 wherein the block copolymer comprises a second block that comprises a polyalkylene oxide.
22 . The surface-modified nanoparticle recited in claim 18 wherein the block copolymer comprises a second block that comprises polyethylene oxide.
23 . The surface-modified nanoparticle recited in claim 16 wherein the block copolymer comprises a polyalkylene glycol-poly(alkylene sulfide) block copolymer.
24 . The surface-modified nanoparticle recited in claim 23 wherein the block copolymer has the general formula
where m and n are integers.
25 . The surface-modified nanoparticle recited in claim 16 wherein the block copolymer comprises a first block that is a reversible addition fragmentation chain transfer agent (RAFT-CTA) and a second block that is a polyalkylene glycol.
26 . The surface-modified nanoparticle recited in claim 25 wherein the block copolymer has the general formula
where n is a positive integer.
27 . A method for modifying the surface of nanoparticles comprising:
preparing a solution of nanoparticles in a solvent;
exposing the nanoparticle solution to a solution of an amphiphilic macromolecule in a solvent.
28 . The method for modifying the surface of nanoparticles recited in claim 27 wherein the solvent is toluene.
29 . The method for modifying the surface of nanoparticles recited in claim 27 wherein exposing the nanoparticle solution to a solution of an amphiphilic macromolecule is performed under an inert atmosphere.
30 . The method for modifying the surface of nanoparticles recited in claim 27 wherein exposing the nanoparticle solution to a solution of an amphiphilic macromolecule is accomplished with an excess of amphiphilic macromolecules.
31 . The method for modifying the surface of nanoparticles recited in claim 27 further comprising:
adding epoxy resin components to the mixture of nanoparticles and amphiphilic macromolecules.
32 . The method recited in claim 32 further comprising:
depositing a film of the nanoparticle-containing resin on a substrate.