Effect pigments and structural colorants incorporating fluorescent particles

1. An effect pigment comprising:

a substrate;

an outer layer disposed above the substrate;

an intermediate layer disposed between the outer layer and the substrate, optionally wherein the intermediate layer comprises a plurality of layers disposed between the substrate and the outer layer; and

particles disposed above the substrate;

wherein:

the particles comprise quantum dots; and

the particles are:

disposed as a layer between the intermediate layer and the outer layer,

disposed as a layer between the substrate and the intermediate layer, or are embedded within the intermediate layer.

2. The effect pigment of claim 1 , wherein the quantum dots have an average diameter from about 0.1 nanometer to about 200 nanometers.

3. The effect pigment of claim 1 , wherein the quantum dots comprise zinc oxide quantum dots.

4. The effect pigment of claim 1 , wherein the outer layer comprises a metal oxide selected from the group consisting of SiO 2 , TiO 2 , In 2 O 3 , ZrO 2 , Fe 2 O 3 , Fe 3 O 4 , Al 2 O 3 , Cr 2 O 3 , CeO 2 , ZnO, SnO 2 , and a combination of any two or more thereof.

5. The effect pigment of claim 1 , wherein the outer layer comprises one or more of SiO 2 or TiO 2 .

6. The effect pigment of claim 1 , wherein the particles are present in the effect pigment from about 0.10 wt. % to about 50 wt. % based on a total weight of the substrate.

7. The effect pigment of claim 1 , wherein the substrate is a platy substrate selected from the group consisting of iron oxide, synthetic mica, natural mica, basic lead carbonate, flaky barium sulfate, SiO 2 , Al 2 O 3 , TiO 2 , glass, ZnO, ZrO 2 , SnO 2 , BiOCl, chromium oxide, BN, MgO flakes, Si 3 N 4 , graphite, aluminum, titanium, aluminum alloys, bronzes, iron, and perlite.

8. The effect pigment of claim 1 , wherein the intermediate layer comprises the plurality of layers disposed between the substrate and the outer layer and the particles are embedded within one or more of the plurality of layers.

9. The effect pigment of claim 1 , wherein the intermediate layer comprises the plurality of intermediate layers disposed between the substrate and the outer layer, wherein the substrate, the particles, the plurality of intermediate layers, and the outer layer collectively define a layer structure of the effect pigment selected from a group consisting of:

substrate/SiO 2 /TiO 2 /particles/Fe 2 O 3 ,

substrate/SnO 2 /TiO 2 /particles/TiO 2 ,

substrate/TiO 2 /SiO 2 /particles/Fe 2 O 3 ,

substrate/TiO 2 /SiO 2 /particles/TiO 2 ,

substrate/Fe 2 O 3 /SiO 2 /particles/Fe 2 O 3 ,

substrate/Fe 2 O 3 /SiO 2 /particles/TiO 2 ,

substrate/TiO 2 /SiO 2 /particles/Cr 2 O 3 ,

substrate/TiO 2 /SiO 2 /TiO 2 /particles/TiO 2 ,

substrate/TiO 2 /SiO 2 /particles/TiO 2 ,

substrate/TiO 2 /SiO 2 /TiO 2 /particles/SiO 2 , and

substrate/TiO 2 /SiO 2 /particles/SiO 2 .

10. A method of producing an effect pigment according to claim 1 , the method comprising:

providing a substrate;

depositing an intermediate layer;

depositing particles;

and

depositing an outer layer;

wherein:

the particles are deposited before or after the intermediate layer,

or are embedded in the intermediate layer.

11. The method of claim 10 , wherein depositing the particles comprises depositing the particles via wet chemical deposition.

12. An inverse opal structure comprising a framework defining a plurality of periodically spaced pores, wherein the framework comprises a solid material having quantum dots dispersed therein, and wherein the quantum dots comprise zinc oxide quantum dots.

13. The effect pigment of claim 1 , wherein the particles are disposed as a layer between the intermediate layer and the outer layer.

14. The effect pigment of claim 1 , wherein the particles are disposed as a layer between the substrate and the intermediate layer.