Compression induced stiffening and alignment of liquid crystal elastomers

Patent metadata

Field	Value
Publication number	US-9260570-B2
Application number	US-201313860392-A
Country	US
Kind code	B2
Filing date	Apr 10, 2013
Priority date	Apr 10, 2012
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

In some embodiments, the present disclosure provides methods of strengthening liquid crystal elastomers. In some embodiments, such methods include a step of placing the liquid crystal elastomer in an environment that applies dynamic stress to the liquid crystal elastomer. In further embodiments, the methods of the present disclosure also include a step of providing liquid crystal elastomers for placement in an environment that applies dynamic stress. In some embodiments, the liquid crystal elastomer is in a nematic phase before or during the application of dynamic stress. In some embodiments, the application of dynamic stress enhances the stiffness of the liquid crystal elastomer by more than about 10%. Further embodiments of the present disclosure pertain to liquid crystal elastomers that are made by the methods of the present disclosure.

First claim

What is claimed is:

1. A liquid crystal elastomer with enhanced stiffness,
wherein the liquid crystal elastomer comprises a mobile nematic director capable of rotating or re-orienting in response to dynamic stress, and a mesogen associated with a polymer,
wherein the stiffness of the liquid crystal elastomer is enhanced by placing the liquid crystal elastomer in an environment that applies dynamic stress to the liquid crystal elastomer,
wherein the liquid crystal elastomer is in a nematic phase before or during the application of dynamic stress, and
wherein the application of dynamic stress enhances the stiffness of the liquid crystal elastomer by more than about 10%.

2. The liquid crystal elastomer of claim 1 , wherein the dynamic stress is applied by dynamic compression.

3. The liquid crystal elastomer of claim 1 , wherein the dynamic stress is applied below the nematic to isotropic transition temperature (T NI ) of the liquid crystal elastomer.

4. The liquid crystal elastomer of claim 1 , wherein the liquid crystal elastomer is a polydomain liquid crystal elastomer.

5. The liquid crystal elastomer of claim 1 , wherein the liquid crystal elastomer has a mesogen content ranging from about 20% molar content to about 90% molar content of the liquid crystal elastomer.

6. The liquid crystal elastomer of claim 1 , wherein the mesogen is selected from the group consisting of aromatic rings, aliphatic rings, poly aromatic rings, poly aliphatic rings, phenyls, biphenyls, benzenes, and combinations thereof.

7. The liquid crystal elastomer of claim 1 , wherein the mesogen is functionalized with one or more functional groups, wherein the functional groups are selected from the group consisting of alkenes, alkanes, alkynes, carboxyl groups, esters, halogens, and combinations thereof.

8. The liquid crystal elastomer of claim 1 , wherein the polymer is selected from the group consisting of polysiloxanes, poly(methyl)siloxanes (PMS), poly(dimethyl)siloxanes (PDMS), poly(hydrogen methyl)siloxanes (PHMS), and combinations thereof.

9. The liquid crystal elastomer of claim 1 , wherein the mesogen is cross-linked to the polymer.

10. The liquid crystal elastomer of claim 1 , wherein the application of dynamic stress enhances the stiffness of the liquid crystal elastomer by between about 10% to about 90%.

Assignees

• Verduzco Rafael
• Agrawal Aditya
• Chipara Alin Cristian
• Univ Rice William M

Inventors

• Verduzco Rafael
• Agrawal Aditya
• Chipara Alin Cristian

Classifications

• B29K2105/0079

  Liquid crystals · CPC title

• C09K19/3833

  with mesogenic groups in the side chain · CPC title

• B29C71/00 Primary

  After-treatment of articles without altering their shape; Apparatus therefor (B29C44/56, B29C73/00 take precedence; surface shaping B29C59/00 {; for joined or sealed parts B29C66/03; after-treatment specially adapted for vulcanising tyres B29D30/0633}) · CPC title

• C09K19/408

  Polysiloxanes · CPC title

• C08G77/398

  containing boron or metal atoms · CPC title