Evidence of Wormlike Micellar Behavior in Chromonic Liquid Crystals: Rheological, X-ray, and Dielectric Studies
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...
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| Format: | Article |
| Language: | English |
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American Chemical Society
2007
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| Online Access: | http://umpir.ump.edu.my/id/eprint/5431/ http://umpir.ump.edu.my/id/eprint/5431/1/J.Phys_Chem_B.pdf |
| _version_ | 1848817593321783296 |
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| author | Hegde, Gurumurthy Prasad, S. Krishna Nair, Geetha G. Jayalakshmi, Jayalakshmi |
| author_facet | Hegde, Gurumurthy Prasad, S. Krishna Nair, Geetha G. Jayalakshmi, Jayalakshmi |
| author_sort | Hegde, Gurumurthy |
| building | UMP Institutional Repository |
| collection | Online Access |
| description | 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. |
| first_indexed | 2025-11-15T01:24:14Z |
| format | Article |
| id | ump-5431 |
| institution | Universiti Malaysia Pahang |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T01:24:14Z |
| publishDate | 2007 |
| publisher | American Chemical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | ump-54312018-05-18T01:33:29Z http://umpir.ump.edu.my/id/eprint/5431/ Evidence of Wormlike Micellar Behavior in Chromonic Liquid Crystals: Rheological, X-ray, and Dielectric Studies Hegde, Gurumurthy Prasad, S. Krishna Nair, Geetha G. Jayalakshmi, Jayalakshmi QC Physics 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. American Chemical Society 2007-06-22 Article PeerReviewed application/pdf en http://umpir.ump.edu.my/id/eprint/5431/1/J.Phys_Chem_B.pdf 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) http://pubs.acs.org/doi/pdf/10.1021/jp073190%2B DOI: 10.1021/jp073190+ |
| spellingShingle | QC Physics Hegde, Gurumurthy Prasad, S. Krishna Nair, Geetha G. Jayalakshmi, Jayalakshmi Evidence of Wormlike Micellar Behavior in Chromonic Liquid Crystals: Rheological, X-ray, and Dielectric Studies |
| title | Evidence of Wormlike Micellar Behavior in Chromonic Liquid Crystals: Rheological, X-ray, and Dielectric Studies |
| title_full | Evidence of Wormlike Micellar Behavior in Chromonic Liquid Crystals: Rheological, X-ray, and Dielectric Studies |
| title_fullStr | Evidence of Wormlike Micellar Behavior in Chromonic Liquid Crystals: Rheological, X-ray, and Dielectric Studies |
| title_full_unstemmed | Evidence of Wormlike Micellar Behavior in Chromonic Liquid Crystals: Rheological, X-ray, and Dielectric Studies |
| title_short | Evidence of Wormlike Micellar Behavior in Chromonic Liquid Crystals: Rheological, X-ray, and Dielectric Studies |
| title_sort | evidence of wormlike micellar behavior in chromonic liquid crystals: rheological, x-ray, and dielectric studies |
| topic | QC Physics |
| url | http://umpir.ump.edu.my/id/eprint/5431/ http://umpir.ump.edu.my/id/eprint/5431/ http://umpir.ump.edu.my/id/eprint/5431/ http://umpir.ump.edu.my/id/eprint/5431/1/J.Phys_Chem_B.pdf |