Anti-fingerprint photocatalytic nanostructure for transparent surfaces

Patent metadata

Field	Value
Publication number	US-10478802-B2
Application number	US-201414274642-A
Country	US
Kind code	B2
Filing date	May 9, 2014
Priority date	May 9, 2013
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

Titania-based porous nanoparticle coatings are mechanically robust, with low haze, which exhibit short time scales for decomposition of fingerprint oils under ultraviolet light. The mechanism by which a typical dactylogram is consumed combines wicking of the sebum into the nanoporous titania structure followed by photocatalytic degradation. These TiO2 nanostructured surfaces are also anti-fogging, anti-bacterial, and compatible with flexible glass substrates and remain photocatalytically active in natural sunlight.

First claim

What is claimed is:

1. A structure comprising:
a transparent substrate; and
a multi-layer optically transmissive nanoparticle structure residing on the substrate comprising an outermost layer of titanium dioxide nanoparticles wherein the outermost layer of titanium dioxide nanoparticles of the multi-layer structure is superhydrophilic and oleophilic, and alternating layers of low and high index of refraction materials below the outermost layer to provide broadband anti-reflectivity
wherein the alternating layers of low and high index of refraction materials form a nanoporous coating and have a smaller refractive index than the substrate and
the optically transmissive nanoparticle structure capable of wicking sebum into the nanoporous coating of the nanoparticle structure followed by photocatalytic degradation.

2. The structure of claim 1 , wherein the outermost layer of titanium dioxide nanoparticle is porous.

3. The structure of claim 1 , wherein the multi-layer structure comprises material selected from the group consisting of silicon dioxide, titanium dioxide, silicon, metallic glass, polymer, metal, or combinations thereof to provide a selected functionality.

4. The structure of claim 3 , wherein the selected functionality is anti-reflectivity, anti-fogging, anti-scratch, or anti-bacterial.

5. The structure of claim 1 , wherein the substrate is flexible.

6. The structure of claim 1 , wherein the nanoparticle size and thickness of the multi-layer structure are selected to maximize a photocatalytic effect and to minimize light scattering.

7. The structure of claim 1 , wherein an oil deposition on the outermost layer of titanium dioxide nanoparticles of the structure is degraded after exposure to sunlight.

8. The structure of claim 7 , wherein the oil deposition is degraded within 3 hours of exposure to sunlight.

9. The structure of claim 1 , wherein an oil deposition on the outer most layer of titanium dioxide nanoparticles of the structure is degraded after exposure to UV light.

10. The structure of claim 9 , wherein the oil deposition is degraded within 3 hours of exposure to sunlight.

11. The structure of claim 1 , wherein the size of the titanium dioxide nanoparticles is less than 1 nm.

Assignees

• Cohen Robert E
• Rubner Michael F
• Mckinley Gareth H
• Barbastathis George
• Choi Hyungryul Johnny
• Park Kyu Chul
• Lee Hyo Min
• Massachusetts Inst Technology

Inventors

• Cohen Robert E
• Rubner Michael F
• Mckinley Gareth H
• Barbastathis George
• Choi Hyungryul Johnny
• Park Kyu Chul
• Lee Hyo Min

Classifications

• C03C2217/75

  Hydrophilic and oleophilic coatings · CPC title

• C03C17/007

  containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase · CPC title

• B01J37/0219

  the coating containing organic compounds · CPC title

• B01J37/0244

  Coatings comprising several layers · CPC title

• C09D1/00

  Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances · CPC title