Photoalignment of materials including liquid crystals

Patent metadata

Field	Value
Publication number	US-9441163-B2
Application number	US-201313786904-A
Country	US
Kind code	B2
Filing date	Mar 6, 2013
Priority date	Jun 4, 2012
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

Embodiments described herein relate to compositions, devices, and methods for the alignment of certain materials including liquid crystals. In some cases, a photoresponsive material include a moiety capable of undergoing a di-pi-methane rearrangement. Methods described herein may provide chemically and/or thermally stable alignment materials for use in a various technologies, including transistors, luminescent devices, and liquid crystal devices.

First claim

What is claimed:

1. A polymer, comprising:
a photoreactive species comprising an sp 3 -hybridized carbon covalently bonded to at least two carbon-carbon double bond groups, wherein the photoreactive species is able to undergo a di-pi-methane rearrangement upon exposure to electromagnetic radiation.

2. A device, comprising:
an anisotropic material; and
a photoreactive material in contact with the anisotropic material, the photoreactive material comprising a species comprising an sp 3 -hybridized carbon covalently bonded to at least two carbon-carbon double bond groups, wherein the species undergoes a di-pi-methane rearrangement upon exposure to electromagnetic radiation.

3. A polymer, comprising:
a group having the following structure,

wherein:
R 1 and R 2 can be the same or different and are hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, a carbonyl group, halo, hydroxyl, amino, nitro, or cyano, any of which is optionally substituted, or, R 1 and R 2 are joined together to form an optionally substituted ring; and
R 3-8 can be the same or different and are hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, a carbonyl group, halo, hydroxyl, amino, nitro, or cyano, any of which is optionally substituted.

4. A device, comprising:
an anisotropic material; and
an alignment material comprising a photoproduct of a di-pi-methane rearrangement in physical contact with the anisotropic material.

5. A method, comprising:
providing a polymer comprising a photoreactive species comprising an sp 3 -hybridized carbon covalently bonded to at least two carbon-carbon double bond groups; and
exposing the polymer to electromagnetic radiation under conditions sufficient to promote a di-pi-methane rearrangement, thereby forming a photoproduct.

6. A method for alignment of an anisotropic material, comprising:
exposing a material comprising a photoreactive species to electromagnetic radiation to produce a photoproduct via a di-pi-methane rearrangement of the photoreactive species; and
arranging an anisotropic material in contact with the material.

7. A polymer as in claim 1 , wherein the photoreactive species is attached to the polymer via at least two atoms of the photoreactive species.

8. A polymer as in claim 1 , wherein the polymer backbone exhibits a glass transition temperature above room temperature.

9. A polymer as in claim 1 , further comprising a sensitizer group.

10. A polymer as in claim 1 , having the following structure:

wherein:
A is an aromatic group and comprises the photoreactive species;
C is a sensitizer group;
B and D can be the same or different and are absent, optionally substituted carbon-carbon double bonds, or carbon-carbon triple bonds; and
n is greater than 1.

11. A polymer as in claim 1 , wherein the photoreactive species has the following structure:

wherein:
R 1 and R 2 can be the same or different and are hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, a carbonyl group, halo, hydroxyl, amino, nitro, or cyano, any of which is optionally substituted, or, R 1 and R 2 are joined together to form an optionally substituted ring; and
R 3-8 can be the same or different and are hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, a carbonyl group, halo, hydroxyl, amino, nitro, or cyano, any of which is optionally substituted.

12. A polymer as in claim 1 , comprising the structure:

wherein:
R 1 and R 2 can be the same or different and are hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, a carbonyl group, halo, hydroxyl, amino, nitro, or cyano, any of which is optionally substituted, or, R 1 and R 2 are joined together to form an optionally substituted ring; and
n is greater than 1.

13. A polymer as in claim 12 , comprising the structure:

14. A polymer as in claim 3 , wherein:
R 1 and R 2 can be the same or different and are hydrogen, alkyl, aryl, or a carbonyl group, any of which is optionally substituted, or, R 1 and R 2 are joined together to form an optionally substituted ring; and
R 3-8 can be the same or different and are hydrogen, alkyl, aryl, or a carbonyl group, any of which is optionally substituted.

15. A polymer as in claim 3 , wherein the polymer has the following structure,

wherein:
C is a sensitizer group;
B and D can be the same or different and are absent, optionally substituted carbon-carbon double bonds, or carbon-carbon triple bonds; and
n is greater than 1.

16. A polymer as in claim 3 , comprising the structure:

wherein:
R 1 and R 2 can be the same or different and are hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, a carbonyl group, halo, hydroxyl, amino, nitro, or cyano, any of which is optionally substituted, or, R 1 and R 2 are joined together to form an optionally substituted ring; and
n is greater than 1.

17. A polymer as in claim 16 , comprising the structure:

18. A method as in claim 5 , further comprising subjecting the photoproduct to thermal treatment, wherein the thermal treatment of the photoproduct results in a change in the chemical structure of the photoproduct.

19. A method as in claim 5 , wherein the polymer has the following structure:

wherein:
A is an aromatic group and comprises the photoreactive species;
C is a sensitizer group;
B and D can be the same or different and are absent, optionally substituted carbon-carbon double bonds, or carbon-carbon triple bonds; and
n is greater than 1.

20. A method as in claim 5 , wherein the photoreactive species has the following structure:

wherein:
R 1 and R 2 can be the same or different and are hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, a carbonyl group, halo, hydroxyl, amino, nitro, or cyano, any of which is optionally substituted, or, R 1 and R 2 are joined together to form an optionally substituted ring; and
R 3-8 can be the same or different and are hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, a carbonyl group, halo, hydroxyl, amino, nitro, or cyano, any of which is optionally substituted.

21. A method as in claim 5 , wherein, upon formation of the photoproduct via the di-pi-methane rearrangement, a directional change in the polymer occurs that substantially does not relax thro

Assignees

• Massachusetts Inst Technology

Inventors

• Swager Timothy M
• Cox Jason R

Classifications

• C08G16/00

  Condensation polymers of aldehydes or ketones with monomers not provided for in the groups C08G4/00 - C08G14/00 (with polynitriles C08G69/38) · CPC title

• C08G2261/92

  TFT applications · CPC title

• C08G2261/3422

  conjugated, e.g. PPV-type · CPC title

• C09K19/56 Primary

  Aligning agents · CPC title

• C08G2261/72

  Derivatisation · CPC title