What question did this study set out to answer?

To evaluate the phase behavior and characterize potential liquid crystalline structures in aqueous solutions of ultrasonically degraded κ-carrageenan.

January 1, 1996Macromolecules

A Novel Chiral Nematic Phase in Aqueous κ-Carrageenan

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Authors

JBJohan BorgströmWrexham University PQPer-Ola QuistAstraZeneca (Sweden)LPLennart PiculellLund University

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Implication

Experimental study demonstrates a chiral nematic liquid crystalline phase in degraded aqueous kappa-carrageenan, indicating thermodynamic equilibrium under macroscopic phase separation.

Key Points

To evaluate the phase behavior and characterize potential liquid crystalline structures in aqueous solutions of ultrasonically degraded κ-carrageenan.
Prepared solutions of ultrasonically degraded κ-carrageenan in 0.1 M NaI at concentrations between 5% and 11% (w/w) via direct mixing and osmotic compression.
Analyzed phase structures and transitions using small-angle X-ray scattering (SAXS), 23Na NMR, and polarized light microscopy.
Tested thermodynamic equilibrium by thermally melting the anisotropic phase at 65 °C and observing room-temperature phase reformation, comparing results with intact κ-carrageenan.
Ultrasonically degraded κ-carrageenan underwent macroscopic phase separation into an isotropic upper phase and an anisotropic, chiral nematic lower phase between 5% and 11% (w/w).
The anisotropic phase melted completely at 65 °C into an isotropic liquid and re-formed upon standing at room temperature, confirming thermodynamic equilibrium.
Intact κ-carrageenan failed to display macroscopic liquid crystalline phase separation, yielding birefringent gels at concentrations exceeding 2%.

Cite This Study

Borgström et al. (1996) studied this question.

synapsesocial.com/papers/6a9a9bc2734e2f6aba347402 https://doi.org/10.1021/ma960315s

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Implication

Experimental study demonstrates a chiral nematic liquid crystalline phase in degraded aqueous kappa-carrageenan, indicating thermodynamic equilibrium under macroscopic phase separation.

A Novel Chiral Nematic Phase in Aqueous κ-Carrageenan

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Implication

Key Points

Cite This Study

A Novel Chiral Nematic Phase in Aqueous κ-Carrageenan

Discussion

Member takes

Implication

Key Points

Cite This Study

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