Structurally colored materials with spectrally selective absorbing components and methods for making the same

Patent metadata

Field	Value
Publication number	US-2016168386-A1
Application number	US-201414907197-A
Country	US
Kind code	A1
Filing date	Jul 13, 2014
Priority date	Jul 31, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

A structurally colored pigment is described that contains a plurality of photonic crystal particles dispersed in a medium, where each photonic crystal particles contains a plurality of spectrally selective absorbing components dispersed within the photonic crystal particle. In certain embodiments, each photonic crystal particle has a predetermined minimum number of repeat units of the photonic crystal structure. The structurally colored material provides improved reflectance, long-term stability, and control of the desired optical effects. The fabrication techniques described herein also provide high throughput and high yield allowing use in wide ranging applications from cosmetics, paints, signs, sensors, to packaging material.

First claim

1 . A pigment comprising:
a plurality of photonic crystal particles dispersed in a medium, each photonic crystal particles containing a plurality of spectrally selective absorbing components dispersed within the photonic crystal particle that selectively absorb electromagnetic radiation without substantially absorbing electromagnetic radiation near the resonant wavelength of the photonic crystal particle, wherein each photonic crystal particle has a predetermined minimum number of repeat units of the photonic crystal structure, wherein the predetermined minimum number of repeat units is related to the resonant wavelength, the full-width at half maximum of the resonant wavelength, and the refractive index contrast in the photonic crystal.

2 . The pigment of claim 1 , wherein the photonic crystal structure is an inverse or a direct opal structure.

3 . The pigment of claim 1 , wherein the spectrally selective absorbing components are gold nanoparticles or silver nanoparticles.

4 . The pigment of claim 1 , wherein the collection exhibits a red structural color.

5 . The pigment of claim 1 , wherein the photonic crystal particles are bricks or spheres.

6 . The pigment of claim 1 , wherein the photonic crystal structure is an inverse opal structure and the spectrally selective absorbing components are gold nanoparticles and the structurally colored material exhibits a red structural color.

7 . The pigment of claim 1 , wherein the spectrally selective absorbing components comprise gold nanoparticles, silver nanoparticles copper nanoparticles, aluminum nanoparticles, inorganic semiconductor nanoparticles, or combinations thereof.

8 . The pigment of claim 1 , wherein the spectrally selective absorbing components are rods, plates or quantum dots.

9 . The pigment of claim 1 , wherein said photonic crystal particles comprise silica, titania, zirconia, alumina, polymeric materials, silicone, carbonates, sulfates, phosphates, inorganic salts, quartz, sapphire, silicon, and combinations thereof.

10 . The pigment of claim 1 , wherein the photonic crystals particles have a coating that provides UV protection properties, antimicrobial properties, anti-inflammatory properties, controlled release of desired molecules, photocatalytic properties or combinations thereof.

11 . The pigment of claim 1 , wherein the plurality of particles provide an angular independent structural color to an observer regardless of angles of observation.

12 . The pigment of claim 1 , wherein the pigment is used in paints, cosmetics, pastes or combinations thereof.

13 . The pigment of claim 1 , wherein the predetermined minimum number of repeat units of the photonic crystal structure is 12 repeat units.

14 . The pigment of claim 1 , wherein the spectrally selective absorbing components reduce the reflectance of the resonant wavelength by no more than 0.2.

15 . A method for forming a pigment of claim 1 , the method comprising:
forming a sacrificial layer over a substrate; forming one or more channel walls over said sacrificial layer; forming a plurality of photonic crystal particles within said one or more channel walls, wherein said plurality of photonic crystal particles comprise a spectrally selective absorbing component that selectively absorb electromagnetic radiation without substantially absorbing electromagnetic radiation near the resonant wavelength of the photonic crystal particle, and wherein each photonic crystal particle has at least a predetermined minimum number of repeat units of the photonic crystal structure, wherein the predetermined minimum number of repeat units is related to the resonant wavelength, the full-width at half maximum of the resonant wavelength, and the refractive index contrast in the photonic crystal; removing said sacrificial layer and said one or more channel walls to obtain a plurality of photonic crystal particles; and dispersing the plurality of photonic crystal particles into a medium.

16 . The method of claim 15 , wherein said sacrificial layer and said one or more channel walls are formed using a photoresist.

17 . The method of claim 15 , wherein said forming a photonic crystal structure comprises providing one or more colloidal particles within said one or more channel walls.

18 . The method of claim 17 , wherein said forming a photonic crystal structure further comprises providing a matrix material surrounding said one or more colloidal particles and removing said one or more colloidal particles.

19 . The method of claim 15 , wherein said removing comprises dissolution or heating of said sacrificial layer and said on or more channel walls.

20 . The method of claim 15 , wherein the predetermined minimum number of repeat units is 12.

21 . A method for forming a pigment of claim 1 , the method comprising:
forming an aqueous mixture of colloidal particles and spectrally selective absorbing components;
mixing said aqueous mixture with an oil to form emulsion droplets, each droplet comprising water, colloidal particles and spectrally selective absorbing components; and
removing said water from said emulsion droplets to form a plurality of photonic crystal particles, and
dipersing the plurality of photonic crystal particles into a medium, wherein said plurality of photonic crystal particles comprise a spectrally selective absorbing component that selectively absorb electromagnetic radiation without substantially absorbing electromagnetic radiation near the resonant wavelength of the photonic crystal particle and
wherein each photonic crystal particle has a predetermined minimum number of repeat units of the photonic crystal structure, wherein the predetermined minimum number of repeat units is related to the resonant wavelength, the full-width at half maximum of the resonant wavelength, and the refractive index contrast in the photonic crystal.

22 . The method of claim 21 , wherein said aqueous mixture further comprises a matrix material.

23 . The method of claim 21 , further comprising:
removing said colloidal particles.

24 . The method of claim 21 , wherein each photonic crystal particles comprise an inverse opal structures and said spectrally selective absorbing components comprise gold nanoparticles or silver nanoparticles.

25 . The method of claim 21 , wherein said photonic crystal particles comprise silica, titania, zirconia, alumina, polymeric materials, silicone, carbonates, sulfates, phosphates, inorganic salts, quartz, sapphire, silicon, and combinations thereof.

26 . The method of claim 21 , wherein the predetermined minimum number of repeat units is 12.

Assignees

• Harvard College

Inventors

• Aizenberg Joanna
• Vogel Nicolas
• Burgess Ian
• Kolle Mathias
• Shirman Tanya
• Utech Stefanie
• Phillips Katherine
• Weitz David A
• Koay Natalie

Classifications

• A61Q1/02

  Preparations containing skin colorants, e.g. pigments (preparations in powder form A61Q1/12) · CPC title

• A61K8/0283

  Matrix particles · CPC title

• A61K2800/412

  Microsized, i.e. having sizes between 0.1 and 100 microns · CPC title

• A61K8/8176

  Homopolymers of N-vinyl-pyrrolidones. Compositions of derivatives of such polymers · CPC title

• A61Q1/06

  Lipsticks · CPC title