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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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Structure-rheology relationship in monoolein liquid crystals
Shweta Mistry1, Philipp L Fuhrmann2, Auke de Vries3
1Department of Physics, Toronto Metropolitan University, 350 Victoria Street, Toronto, Ontario M5B 2K3, Canada.
Journal of Colloid and Interface Science
|November 10, 2022
Summary
Liquid crystal symmetry dictates the mechanical properties of monoolein phases, influencing yielding and deformation. Strain rate frequency superposition (SRFS) can reveal mesophase relaxation times.
Area of Science:
- Materials Science
- Soft Matter Physics
- Rheology
Background:
- Monoolein liquid crystals are utilized in food and pharmaceutical applications.
- Understanding the relationship between microstructure and rheology is crucial for these applications.
Purpose of the Study:
- To investigate how liquid crystal symmetry influences the yielding and large deformation behavior of monoolein phases.
- To explore the applicability of strain rate frequency superposition (SRFS) for determining mesophase relaxation times.
Main Methods:
- Characterization of liquid crystal microstructure using small-angle X-ray scattering (SAXS) and polarized light microscopy.
- Rheological analysis including frequency and amplitude sweeps, large amplitude oscillatory shear tests, and SRFS.
- Correlation of structural and rheological data with temperature and composition.
Main Results:
- Established structure-rheology relationships for lamellar, cubic, and hexagonal monoolein-water mesophases.
- Cubic phases exhibited the highest elasticity and abrupt yielding, followed by lamellar and hexagonal phases.
- Liquid crystal symmetry was identified as the defining factor for rheological behavior under large deformation.
Conclusions:
- Liquid crystal symmetry is a dominant factor controlling yielding and large deformation properties.
- SRFS is a viable method for determining mesophase relaxation times.
- The study provides insights into tailoring monoolein liquid crystal properties for specific applications.
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