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Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions
Published on: April 19, 2018
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Structural Rheology of the Smectic Phase
Shuji Fujii1,2, Shigeyuki Komura3, Chun-Yi David Lu4
1Department of Chemistry, Nagaoka University of Technology, Nagaoka 940-2188, Japan. sfujii@mst.nagaokaut.ac.jp.
Materials (Basel, Switzerland)
|August 10, 2017
Summary
Dislocation unbinding in liquid crystals significantly impacts focal conic domain size and rheological properties. This structural change in smectic phases offers insights into layered systems and elasticity origins.
Area of Science:
- Materials Science
- Soft Matter Physics
- Rheology
Background:
- Thermotropic smectic liquid crystals exhibit complex rheological behaviors.
- Focal conic domains (FCDs) are characteristic microstructures in smectic liquid crystals.
- Dislocation loop unbinding is a key phenomenon driving phase transitions in smectic liquid crystals.
Purpose of the Study:
- To review the rheological properties of 8CB smectic liquid crystals with FCDs.
- To explore the influence of dislocation loop unbinding on FCD evolution and rheology.
- To investigate the role of dislocations in the structural development of layered systems.
Main Methods:
- Structural rheology analysis of thermotropic smectic liquid crystals.
- Examination of FCD formation from perpendicularly oriented smectic layers.
- Comparative rheological analysis of smectic FCDs and lyotropic lamellar onion structures.
Main Results:
- Dislocation loop unbinding affects FCD size evolution and both linear and nonlinear rheological behaviors.
- Dislocations are crucial for structural development in layered systems.
- Similarities in rheology between smectic FCDs and lyotropic onion structures suggest a common physical origin for elasticity.
Conclusions:
- The unbinding of dislocation loops is a critical factor governing the rheological properties of smectic liquid crystals.
- Dislocations play a fundamental role in the structural organization and evolution of layered soft matter systems.
- Elasticity in both smectic FCDs and lyotropic onion structures may stem from shared physical principles.
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