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An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation
Published on: February 27, 2019
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Tunable and Switchable Thermochromism in Cholesteric Liquid Crystalline Elastomers
Kyle R Schlafmann1, Mohammed S Alahmed1, Harrison M Pearl1
1Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80303, United States.
ACS Applied Materials & Interfaces
|April 26, 2024
Summary
Researchers developed novel thermochromic materials using liquid crystalline elastomers (CLCEs). These CLCEs offer a unique, reversible color change mechanism based on temperature, distinct from traditional leuco dyes.
Area of Science:
- Materials Science
- Polymer Chemistry
- Optics
Background:
- Thermochromic materials are widely used as temperature indicators, typically employing leuco dyes in polymeric resins.
- These conventional materials change color with temperature but offer limited tunability and distinct mechanisms.
- Liquid crystalline elastomers (LCEs) present an alternative platform for thermochromism through structural changes.
Purpose of the Study:
- To explore a novel thermochromic approach using cholesteric liquid crystalline elastomers (CLCEs).
- To systematically prepare and investigate CLCEs with reversible thermochromic responses.
- To tune thermochromic properties by controlling cross-link density and liquid crystalline composition.
Main Methods:
- Preparation of CLCEs by incorporating chiral and achiral liquid crystalline monomers.
- Systematic variation of cross-link density and liquid crystalline composition.
- Characterization of thermochromic response based on selective reflection changes with temperature.
Main Results:
- CLCEs exhibited reversible thermochromic behavior due to temperature-induced changes in helicoidal structure, birefringence, and thickness.
- Tuning cross-link density and composition allowed for control over the nematic-isotropic transition temperature.
- Low birefringence compositions enabled tunable thermochromic reflection and switching.
Conclusions:
- CLCEs offer a distinct and tunable mechanism for thermochromism based on structural transitions.
- The developed CLCEs provide a promising alternative to conventional thermochromic materials for temperature indication.
- Further research can leverage these CLCEs for advanced optical applications requiring precise temperature-dependent color changes.
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