OPTICAL COATING COMPRISING POROUS SILICA NANOPARTICLES

• US 20130216807A1
• Filed: 08/19/2011
• Published: 08/22/2013
• Est. Priority Date: 08/20/2010
• Status: Abandoned Application

• Current Assignee: Quantum Energy Technologies
• Original Assignee: Quantum Energy Technologies
• Inventors: Wakefield, Gareth, Gardener, Martin, Ostrowski, Sasha
• Application Number:
  US13/817,268
• Publication Number:
  US 20130216807A1
• Time in Patent Office: Days
• US Class Current: 428/218
• CPC Class Codes: G02B 1/111 using layers comprising organic materials
• CPC Class Codes: G02B 1/113 using inorganic layer materials only
• CPC Class Codes: G02B 2207/107 Porous materials, e.g. for reducing the refractive index
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/24992 Density or compression of components
• CPC Class Codes: Y10T 428/249974 Metal- or silicon-containing element

Abstract

An optical coating comprising a binder and a plurality of porous silica nanoparticles in which the pores are randomly oriented, a solution for forming an optical coating comprising a solvent and a plurality of porous silica nanoparticles in which the pores are randomly oriented, a method for fabricating an optical coating, and the use of porous silica nanoparticles in which the pores are randomly oriented in the manufacture of an optical coating.

Claims

1. An optical coating comprising:

a binder; and

a plurality of porous silica nanoparticles in which the pores are randomly oriented.

4. The coating as claimed in claim 1, wherein the pores have an internal surface at least partially comprising a hydrophobic layer.

5. The coating as claimed in claim 4, wherein the binder is hydrophilic.

6. The coating as claimed in claim 5, wherein the binder is tetraethoxysilane or a siloxane-based hardcoat comprising 3-glycidoxypropyltrimethoxysilane.

7. The coating as claimed in claim 1, in which there is substantially no binder ingress into the pores.

8. The coating as claimed in claim 1, wherein at least 50% of the volume of the pores is air.

9. The coating as claimed in claim 1, wherein the nanoparticles have a mean pore diameter of less than 10 nm.

10. The coating as claimed in claim 1, wherein the nanoparticles have an average diameter in the range 20-30 nm.

12. The coating as claimed in claim 1, wherein the optical coating has an elastic modulus greater than half and less than twice the elastic modulus of the underlying substrate.

13. A solar cell, lens, lighting component, window or glass panel comprising an optical coating as claimed in claim 1.

14. The combination of a substrate and an optical coating as claimed in claim 1, wherein the coating has a refractive index of ±

20% of the square root of the refractive index of the substrate.

2. A solution for forming an optical coating comprising:

a solvent; and

a plurality of porous silica nanoparticles in which the pores are randomly oriented.

3. A method of fabricating an optical coating, said method comprising:

preparing either (i) a solution for forming an optical coating comprising a binder, a solvent, and a plurality of porous silica nanoparticles in which the pores are randomly oriented, or

(ii) two solutions for forming an optical coating, one comprising a binder and a solvent and one comprising a plurality of porous silica nanoparticles in which the pores are randomly oriented and a solvent;

applying the solution or solutions to a substrate; and

removing solvent from the solution or solutions to form the optical coating.

11. The method as claimed in claim 3, wherein a surface of the substrate to which the optical coating is to be applied is treated before application of the solution or solutions, the treatment increasing the surface energy of the substrate.

15. A use of porous silica nanoparticles in which the pores are randomly oriented in the manufacture of an optical coating.