Evidence of Wormlike Micellar Behavior in Chromonic Liquid Crystals: Rheological, X-ray, and Dielectric Studies

Hegde, Gurumurthy and Prasad, S. Krishna and Nair, Geetha G. and Jayalakshmi, Jayalakshmi (2007) Evidence of Wormlike Micellar Behavior in Chromonic Liquid Crystals: Rheological, X-ray, and Dielectric Studies. Journal of Physical Chemistry B, 111 (33). pp. 9741-9746. ISSN 1520-6106 (print); 1520-5207 (online). (Published)

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Abstract

We report rheological, X-ray, and dielectric investigations on a chromonic liquid-crystalline system formed by aqueous solutions of a food coloring agent, Sunset Yellow, in the absence and upon addition of salt. The salt-concentration dependence of the steady-state viscosity at low shear rates has a non-monotonic variation and is qualitatively similar to the behavior seen in wormlike micellar systems, a surprising result since chromonic systems are expected to be non-micellar in character. More interestingly, for a particular low concentration of the salt (20 mM), the viscosity increases by 3 orders of magnitude in comparison with that of the pure chromonic material. The dynamic (oscillatory) rheological data bring out features which can be described in terms of a microstructure formation. X-ray and dielectric studies show that certain characters of the aggregates formed by the Sunset Yellow molecules are not altered by the addition of salt.

Item Type:	Article
Subjects:	Q Science > QC Physics
Faculty/Division:	Faculty of Industrial Sciences And Technology
Depositing User:	Dr. Gurumurthy Hegde
Date Deposited:	09 May 2014 03:57
Last Modified:	18 May 2018 01:33
URI:	http://umpir.ump.edu.my/id/eprint/5431
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