Encapsulated polymer stabilized cholesteric texture light shutter

Patent metadata

Field	Value
Publication number	US-9835894-B2
Application number	US-201615065047-A
Country	US
Kind code	B2
Filing date	Mar 9, 2016
Priority date	Jun 1, 2012
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

An encapsulated polymer stabilized cholesteric texture (EPSCT) light shutter is formed from a cholesteric liquid crystal and monomer that is encapsulated into micron sized, polymer-coated droplets by either an emulsification or phase separation process. The polymer-coated droplets are disposed between transparent electrodes, where they are irradiated by ultra-violet (UV) light to polymerize the monomer.

First claim

What is claimed is:

1. A method of forming a light shutter comprising:
providing a polymer material;
fully encapsulating a liquid crystal material and a monomer material into one or more shells formed by the polymer material;
disposing the polymer material and the shells included therein between a pair of conductive at least partially light transparent electrodes; and
polymerizing the monomer material to form a polymer network within the shells.

2. The method of claim 1 , wherein the polymer material comprises a mixture of water and a water soluble polymer, and
wherein the encapsulating step is carried out by:
mixing the liquid crystal material, the monomer material, and the polymer material together.

3. The method of claim 2 , wherein the disposing step is carried out by coating the mixed liquid crystal material, the monomer material, and the polymer material onto one of the electrodes.

4. The method of claim 1 , wherein the polymer material comprises a thermoplastic polymer, and wherein the encapsulating step is carried out by:
heating a mixture of the liquid crystal material, the monomer material, and the thermoplastic polymer; and cooling the mixture.

5. The method of claim 1 , wherein the electrodes comprise indium-tin-oxide (ITO).

6. The method of claim 1 , wherein the polymerizing step is carried out by exposing the monomer material to UV (ultraviolet) light.

7. The method of claim 6 , wherein the polymerizing step further includes:
exposing the monomer material to an electric field.

8. The method of claim 1 , wherein the size of the one or more shells is about 1 to 100 μm.

9. The method of claim 1 , wherein the disposing step is performed by a roll-to-roll process.

10. The method of claim 1 , wherein the liquid crystal material comprises nematic liquid crystal material.

11. The method of claim 1 , wherein the liquid crystal material is chiral nematic liquid crystal material or cholesteric liquid crystal material.

12. A light shutter comprising:
a pair of at least partially light transparent electrodes;
a polymer material disposed between the electrodes;
a plurality of shells entirely formed by the polymeric material; and
liquid crystal material stabilized within the shells by a polymer network.

13. The light shutter of claim 12 , wherein the electrodes are formed of indium-tin-oxide (ITO).

14. The light shutter of claim 12 , wherein the liquid crystal material comprises nematic liquid crystal material.

15. The light shutter of claim 12 , wherein the light shutter is self-adhesive.

16. The light shutter of claim 12 , wherein the polymer network is substantially perpendicular to at least one of the electrodes and divides the liquid crystal material into a plurality of domains.

17. The method of claim 12 , wherein the liquid crystal material is chiral nematic liquid crystal material or cholesteric liquid crystal material.

18. A method of forming a light shutter comprising:
providing a polymer material;
fully encapsulating liquid crystal material into a plurality of shells within the polymer material; and
stabilizing the liquid crystal material within the shells by a polymer network.

19. The method of claim 18 , wherein the liquid crystal material comprises nematic liquid crystal material.

20. The method of claim 18 , further comprising:
disposing the polymer between a pair of at least partially light transparent electrodes.

Assignees

• Yang Deng-Ke
• Cui Yue
• Zhang Cuiyu
• Univ Kent State Ohio

Inventors

• Yang Deng-Ke
• Cui Yue
• Zhang Cuiyu

Classifications

• G02F1/137

  characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering · CPC title

• B05D5/065

  having colour interferences or colour shifts or opalescent looking, flip-flop, two tones · CPC title

• G02F1/1334 Primary

  based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals · CPC title

• G02F2001/13775

  Physics · mapped topic

• G02F1/13439

  characterised by their electrical, optical, physical properties; materials therefor; method of making · CPC title