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Isotropic to smectic-C phase transition in liquid-crystalline elastomers.
1Department of Physics, Presidency University, 86/1 College Street, Kolkata 700 073, India. pkmuk1966@gmail.com
The Journal of Chemical Physics
|April 17, 2012
Summary
This study models the isotropic-smectic-C phase transition in liquid-crystalline elastomers, finding mechanical stress doesn't alter the transition order. Theoretical calculations align well with experimental data for heat capacity and dielectric effects.
Area of Science:
- Materials Science
- Polymer Science
- Condensed Matter Physics
Background:
- Liquid-crystalline elastomers exhibit unique phase transitions influenced by molecular structure and external stimuli.
- The isotropic-smectic-C phase transition is a key phenomenon in liquid crystals, typically first-order in low-molecular-weight systems.
- Understanding the behavior of these transitions in elastomers is crucial for developing advanced materials.
Purpose of the Study:
- To develop a phenomenological model for the isotropic-smectic-C phase transition in liquid-crystalline side-chain elastomers.
- To investigate the impact of external mechanical stress on this phase transition.
- To calculate thermodynamic properties like heat capacity and nonlinear dielectric effect in the isotropic phase.
Main Methods:
- Development of a phenomenological model.
- Analysis of the influence of external mechanical stress.
- Calculation of temperature dependence of heat capacity.
- Calculation of nonlinear dielectric effect in the isotropic phase.
Main Results:
- The isotropic-smectic-C phase transition in liquid-crystalline elastomers remains first-order, unaffected by mechanical stress.
- Theoretical predictions for heat capacity and nonlinear dielectric effect show good agreement with experimental observations.
- The model successfully describes the behavior of liquid-crystalline elastomers near the phase transition.
Conclusions:
- The developed model accurately captures the isotropic-smectic-C phase transition in liquid-crystalline elastomers.
- External mechanical stress does not alter the fundamental order of this transition in these materials.
- The findings provide valuable insights into the physics of liquid-crystalline elastomers and their response to external fields.
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