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High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
External field-induced switching in nematic elastomers: a Monte Carlo study
1Dipartimento di Chimica Fisica ed Inorganica and INSTM, Università di Bologna, Viale Risorgimento 4, I-40136, Bologna, Italy. gregor.skacej@fmf.uni-lj.si
The European Physical Journal. E, Soft Matter
|July 21, 2006
Summary
We studied external field effects on nematic elastomers using a lattice model. Unlike typical nematics, these elastomers show a full-wavelength Fréedericksz transition, with significant shear deformation accompanying molecular reorientation.
Area of Science:
- Soft Matter Physics
- Materials Science
- Polymer Chemistry
Background:
- Nematic elastomers are liquid crystals with unique mechanical properties.
- Understanding their response to external fields is crucial for applications.
- Previous studies on ordinary nematics show a half-wavelength Fréedericksz effect.
Purpose of the Study:
- To investigate external field-induced switching in nematic elastomers.
- To characterize the Fréedericksz transition in these materials.
- To explore the relationship between molecular reorientation and mechanical deformation.
Main Methods:
- Monte Carlo simulations.
- Coarse-grained shearable lattice model.
- Analysis of simulated polarized light textures.
- Deuterium magnetic resonance spectroscopy.
Main Results:
- Observation of a full-wavelength Fréedericksz effect in large systems.
- Distinct polarized light textures and NMR spectra confirming the effect.
- Pronounced shear deformations accompanying mesogenic unit reorientation.
Conclusions:
- Nematic elastomers exhibit a distinct full-wavelength Fréedericksz transition.
- This transition is coupled with significant shear deformation.
- The findings provide insights into the electromechanical coupling in nematic elastomers.
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