Swelling Dynamics of Liquid Crystalline Elastomers

Jun GengLquid Crystal InstituteKent State University

Advisor: Dr. Peter Palffy-Muhoray

Outline Liquid crystal elastomer (LCE) sample

details and preparation Analysis of swelling based on Van der Waals

intermolecular potential Solvent swelling experiment Solvent vapor swelling experiment

2Liquid Crystal Institute, KSU

LCE Details & Preparation

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Finkelmann Spin Cast Nematic side chain LCE

Si O

CH3

H

O C

O

O OCH3

O

O

O

O C

O

O

CH3

CH3

CH3CH3

CH3

n

9

9

9

1

2

3

4

100 mol.%

72 mol.%

18 mol.%

10 mol.%

Si O

CH3

H

O C

O

O OCH3

O

O

O

O C

O

O

CH3

CH3

CH3CH3

CH3

n

9

9

9

1

2

3

4

100 mol.%

72 mol.%

18 mol.%

10 mol.%

Si O

CH3

H

O C

O

O OCH3

O

O

O

O C

O

O

CH3

CH3

CH3CH3

CH3

n

9

9

9

1

2

3

4

100 mol.%

72 mol.%

18 mol.%

10 mol.%

Si O

CH3

H

O C

O

O OCH3

O

O

O

O C

O

O

CH3

CH3

CH3CH3

CH3

n

9

9

9

1

2

3

4

100 mol.%

72 mol.%

18 mol.%

10 mol.%

Si O

85

CH3

H

methylsiloxane backbone

tri-functional crosslinker

biphenyl mesogen(side group)

Simple Analysis

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¢ f = ¢ fnem atic+ ¢ fm ix + ¢ felastic

Solvent Swelling Experiment Designed measurement cell

to simultaneously monitor Initial problems:

Solvent leaking UV glue degradation

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Swelling Experiment

solvent reservoir

solvent pump sample

holder

L1

L2

L3director

LCE

Solvent Vapor Swelling

LCE Bi-Rubber Strip Swelling

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Normal Rubber: RTV

Liquid Crystal Elastomer

Toluene

Toluene Vapor

Conclusion

Thanks to:

Jeremy taught me how to use those machines in machine shop and

supervised my activities, Paul who showed me how to make the

elastomers, Michele who lent me a

key to the lab, and Jake who told jokes sometimes.