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Preparation of Monodomain Liquid Crystal Elastomers and Liquid Crystal Elastomer Nanocomposites
Published on: February 6, 2016
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Adaptable liquid crystal elastomers with transesterification-based bond exchange reactions.
Drew W Hanzon1, Nicholas A Traugutt1, Matthew K McBride2
1Department of Mechanical Engineering, University of Colorado Denver, Denver, CO 80217, USA. kai.2.yu@ucdenver.edu.
Soft Matter
|January 11, 2018
Summary
New adaptable liquid crystal elastomers (LCEs) can be programmed with stress and bond exchange reactions (BERs) for two-way shape switching. These reprogrammable LCEs offer potential for sustainable recycling and advanced material applications.
Area of Science:
- Polymer Science
- Materials Science
- Soft Matter Physics
Background:
- Adaptable liquid crystal elastomers (LCEs) offer novel programming methods for monodomain samples.
- Active bond exchange reactions (BERs) enable polymer chain and mesogen alignment under constant stress.
Purpose of the Study:
- To develop a new adaptable main-chain LCE system utilizing thermally induced transesterification BERs.
- To investigate the programming, shape-switching behavior, and reprogrammability of these LCEs.
Main Methods:
- Development of a main-chain LCE system with thermally induced transesterification BERs.
- Application of constant stress and BERs for programming mesogen alignment.
- Polarized Fourier transform infrared spectroscopy to confirm alignment.
- Examination of factors influencing two-way shape switching strain amplitude.
Main Results:
- Successful programming of LCEs leading to two-way shape switching behavior.
- Demonstration of reprogrammability by disrupting mesogen alignment via heating.
- Confirmation of polymer chain and mesogen alignment using polarized FTIR.
- Investigation of creep stress, temperature, and time effects on shape switching.
Conclusions:
- The developed adaptable LCE system exhibits programmable and reversible shape-switching capabilities.
- The dynamic network allows for stress relaxation and reprogramming.
- Potential applications include surface welding and green recycling due to dissolvability.
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