Accessibility navigation


Effect of ethanol on the micellization and gelation of Pluronic P123

Chaibundit, C., Ricardo, N., Nadja, R., Costa, F., Wong, M.D., Hermida-Merino, D., Rodriguez-Perez, D.J., Hamley, I.W., Yeates, S. and Booth, C. (2008) Effect of ethanol on the micellization and gelation of Pluronic P123. Langmuir, 24 (21). pp. 12260-12266. ISSN 0743-7463

Full text not archived in this repository.

To link to this article DOI: 10.1021/la8022425

Abstract/Summary

In certain applications copolymer P123 (E21P67E21) is dissolved in water-ethanol mixtures, initially to form micellar solutions and eventually to gel. For P123 in 10, 20, and 30 wt % aqueous ethanol we used dynamic light scattering from dilute solutions to confirm micellization, oscillatory rheometry, and visual observation of mobility (tube inversion) to determine gel formation in concentrated solutions and small-angle X-ray scattering (SAXS) to determine gel structure. Except for solutions in 30 wt % aqueous ethanol, a clear-turbid transition was encountered on heating dilute and concentrated micellar solutions alike, and as for solutions in water alone (Chaibundit et al. Langmuir 2007, 23, 9229) this could be ascribed to formation of wormlike micelles. Dense clouding, typical of phase separation, was observed at higher temperatures. Regions of isotropic and birefringent gel were defined for concentrated solutions and shown (by SAXS) to have Cubic (fcc and hcp) and hexagonal structures, consistent with packed spherical and elongated micelles, respectively. The cubic gels (0, 10, and 20 wt % ethanol) were clear, while the hex gels were either turbid (0 and 10 wt % ethanol), turbid enclosing a clear region (20 wt % ethanol), or entirely clear (30 wt % ethanol). The SAXS profile was unchanged between turbid and clear regions of the 20 wt % ethanol gel. Temperature scans of dynamic moduli showed (as expected) a clear distinction between high-modulus cubic gels (G'(max) approximate to 20-30 kPa) and lower modulus hex gels (G'(max) < 10 kPa).

Item Type:Article
Refereed:Yes
Divisions:Faculty of Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
ID Code:11110
Uncontrolled Keywords:ANGLE NEUTRON-SCATTERING, TRIBLOCK COPOLYMER MICELLES, DYNAMIC LIGHT-SCATTERING, AQUEOUS-SOLUTION, BLOCK-COPOLYMERS, ETHYLENE-OXIDE, 1,2-BUTYLENE OXIDE, ASSOCIATION PROPERTIES, WORMLIKE MICELLES, DIBLOCK COPOLYMER

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation