uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Structural transitions in cholesterol-based wormlike micelles induced by encapsulating alkyl ester oils with varying architecture
Institute of Pharmaceutical Science, King’s College London, UK.
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
ISIS-CCLRC, Rutherford Appleton Laboratory, Chilton, UK.
Institute of Pharmaceutical Science, King’s College London, UK.
2012 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 378, no 1, 125-134 p.Article in journal (Refereed) Published
Abstract [en]

The effect of encapsulating oils on the phase behaviour and the microstructure of wormlike micelles formed by polyoxyethylene cholesteryl ether (ChEO10) and triethylene glycol monododecyl ether co-surfactant (C12EO3) was investigated using rheology, Cryo-TEM and small-angle neutron scattering measurements. Six alkyl ester oils bearing small, systematic variations in their molecular structure were encapsulated: ethyl butyrate (EB24), ethyl caproate (ECO26), ethyl caprylate (EC28), methyl enanthate (ME17), methyl caprylate (MC18) and butyl butyrate (BB44), where the subscripts refer to the length of the alkyl chain and fatty acid chain, respectively, on either sides of the ester link. The addition of alkyl ester oils to ChEO10/C12EO3 solutions promotes the longitudinal growth of the surfactant aggregates into wormlike micelles possessing an elliptical cross-section, with rminor 31 Â± 2 Ã… and rmajor varying from 45 to 70 Ã…. At fixed alkyl chain length, oils with longer fatty acid chains were found to be more efficient in inducing wormlike micelle formation or their elongation, following the order: EC28 > ECO26 > EB24. Instead, at fixed fatty acid chain length, increasing the alkyl chain has a negative effect on the longitudinal micellar growth (MC18 > EC28 and EB24 > BB44). At high co-surfactant concentrations and in the presence of EB24, an unusual phase of ring-like micelles was detected. Overall, the orientation of the oil molecules within the micelles enables them to act as co-surfactants with a small head-group, decreasing the average cross-section area and promoting longitudinal growth of the micelles into worms.

Place, publisher, year, edition, pages
2012. Vol. 378, no 1, 125-134 p.
Keyword [en]
Wormlike micelles, Polyoxyethylene cholesteryl ether, Oil encapsulation, Viscoelastic behaviour, Small-angle neutron scattering, Ring-like micelles
National Category
Chemical Sciences
URN: urn:nbn:se:uu:diva-176853DOI: 10.1016/j.jcis.2012.04.014ISI: 000305165500017OAI: oai:DiVA.org:uu-176853DiVA: diva2:537264
Available from: 2012-06-26 Created: 2012-06-26 Last updated: 2012-07-31Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Karlsson, Göran
By organisation
Analytical Chemistry
In the same journal
Journal of Colloid and Interface Science
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 384 hits
ReferencesLink to record
Permanent link

Direct link