Composite film, device including, and method of forming the same

Patent metadata

Field	Value
Publication number	US-10996496-B2
Application number	US-201716323984-A
Country	US
Kind code	B2
Filing date	Aug 18, 2017
Priority date	Aug 19, 2016
Publication date	May 4, 2021
Grant date	May 4, 2021

Abstract

In present invention, various embodiments provide a photothermotropic composite film. The composite film comprises a matrix and one or more nanostructures comprising a metal oxide semiconductor which is configured to convert radiant energy to thermal energy. The matrix has a property which is changeable based on the thermal energy received by the matrix from the metal oxide semiconductor. In a preferred embodiment, hybridization of the poly(N-isopropylacrylamide) (PNIPAM) hydrogel and antimony-tin oxide (ATO) is provided as the composite film. In this film, the ATO absorbs at near-infrared (NIR) region and acts as nanoheater to induce the optical switching of the hydrogel. The behaviour of this composite film can be used as a new generation of autonomous passive smart windows for climate-adaptable solar modulation.

First claim

The invention claimed is:

1. A composite film comprising:
a matrix; and
one or more nanostructures comprising a metal oxide semiconductor configured to convert radiant energy to thermal energy,
wherein the matrix comprises poly(N-isopropylacrylamide) hydrogel, the poly(N-isopropylacrylamide) hydrogel having a property which is changeable based on the thermal energy received by the matrix from the metal oxide semiconductor,
wherein the poly(N-isopropylacrylamide) hydrogel is configured to be switched to a first phase allowing less visible light to pass through in response to the thermal energy received by the poly(N-isopropylacrylamide) hydrogel greater than a predetermined level, and to a second phase allowing more visible light to pass through in response to the thermal energy received by the poly(N-isopropylacrylamide) hydrogel less than the predetermined level, and
wherein the metal oxide semiconductor is tin oxide with a doping of antimony in an amount from 5 atomic percent to 10 atomic percent.

2. The composite film according to claim 1 , wherein the poly(N-isopropylacrylamide) hydrogel is configured to undergo a phase transition based on the thermal energy received by the matrix from the metal oxide semiconductor.

3. The composite film according to claim 1 , wherein the one or more nanostructures are embedded in the matrix.

4. The composite film according to claim 1 , wherein the one or more nanostructures are coated or laminated onto the matrix.

5. The composite film according to claim 1 , wherein the metal oxide semiconductor is configured to convert radiant energy of electromagnetic waves in infrared region.

6. The composite film according to claim 1 , wherein the metal oxide semiconductor is configured to convert radiant energy of electromagnetic waves in ultraviolet region.

7. The composite film according to claim 1 , wherein the metal oxide semiconductor is configured to convert radiant energy to thermal energy based on a localized surface plasmon resonance effect.

8. The composite film according to claim 1 , wherein the composite film is configured to allow at least some visible light to pass through.

9. A device comprising a composite film comprising:
a matrix; and
one or more nanostructures comprising a metal oxide semiconductor configured to convert radiant energy to thermal energy;
wherein the matrix comprises poly(N-isopropylacrylamide) hydrogel, the poly(N-isopropylacrylamide) hydrogel having a property which is changeable based on the thermal energy received by the matrix from the metal oxide semiconductor,
wherein the poly(N-isopropylacrylamide) hydrogel is configured to be switched to a first phase allowing less visible light to pass through in response to the thermal energy received by the poly(N-isopropylacrylamide) hydrogel greater than a predetermined level, and to a second phase allowing more visible light to pass through in response to the thermal energy received by the poly(N-isopropylacrylamide) hydrogel less than the predetermined level, and
wherein the metal oxide semiconductor is tin oxide with a doping of antimony in an amount from 5 atomic percent to 10 atomic percent.

10. The device according to claim 9 , wherein the device is any one selected from a group consisting of a smart window, a thermochromic device, and a shape memory device.

11. A method of forming a composite film, the method comprising:
forming a matrix; and
forming one or more nanostructures comprising a metal oxide semiconductor configured to convert radiant energy to thermal energy;
wherein the matrix comprises poly(N-isopropylacrylamide) hydrogel, the poly(N-isopropylacrylamide) hydrogel having a property which is changeable based on the thermal energy received by the matrix from the metal oxide semiconductor,
wherein the poly(N-isopropylacrylamide) hydrogel is configured to be switched to a first phase allowing less visible light to pass through in response to the thermal energy received by the poly(N-isopropylacrylamide) hydrogel greater than a predetermined level, and to a second phase allowing more visible light to pass through in response to the thermal energy received by the poly(N-isopropylacrylamide) hydrogel less than the predetermined level, and
wherein the metal oxide semiconductor is tin oxide with a doping of antimony in an amount from 5 atomic percent to 10 atomic percent.

12. The method according to claim 11 , further comprising:
dispersing the one or more nanostructures in the matrix.

13. The method according to claim 11 , further comprising:
coating or laminating the one or more nanostructures onto the matrix.

14. The method according to claim 11 , wherein the poly(N-isopropylacrylamide) hydrogel is formed via free-radical polymerization.

Assignees

• Univ Nanyang Tech

Inventors

• Hu Xiao
• Lee Heng Yeong

Classifications

• B32B2255/06

  on metal layer · CPC title

• B32B27/28

  comprising synthetic resins not wholly covered by any one of the sub-groups {B32B27/30 - B32B27/42} · CPC title

• B32B2260/046

  Synthetic resin · CPC title

• G02F2201/083

  infrared absorbing · CPC title

• B32B25/042

  of natural rubber or synthetic rubber · CPC title