Journal article
Inverted Micelle‐in‐Micelle Configuration in Cationic/Carbohydrate Surfactant Mixtures
Chemphyschem, Vol.18(1), pp.79-86
01/04/2017
DOI: 10.1002/cphc.201600908
PMID: 27788284
Abstract
Nuclear magnetic resonance is applied to investigate the relative positions and interactions between cationic and non‐ionic carbohydrate‐based surfactants in mixed micelles with D2O as the solvent. This is accomplished by using relaxation measurements [spin‐lattice (T1) and spin‐spin (T2) analysis] and nuclear Overhauser effect spectroscopy (NOESY). This study focuses on the interactions of n‐octyl β‐d‐glucopyranoside (C8G1) and β‐d‐xylopyranoside (C8X1) with the cationic surfactant hexadecyltrimethylammonium bromide (C16TAB). Whereas the interactions between carbohydrate and cationic surfactants are thermodynamically favorable, the NOESY results suggest that both of the sugar head groups are located preferentially at the interior core of the mixed micelles, so that they are not directly exposed to the bulk solution. The more hydrophilic sugar headgroups of C8G1 have more mobility than sugar heads of C8X1 owing to increased hydration. Herein, an inverted carbohydrate configuration in mixed micelles is proposed for the first time and supported by fluorescence spectroscopy experiments. This inverted carbohydrate headgroup configuration would limit the use of these mixed surfactants when access to the carbohydrate headgroup is important, but may present new opportunities where the carbohydrate‐rich core of the micelles can be exploited.
Sweet Surprise: NMR and fluorescence spectroscopy show that the surfactant n‐octyl β‐d‐glucopyranoside (C8G1) segregates with its sugar headgroups clustered at the interior of mixed micelles formed with the cationic surfactant hexadecyltrimethylammonium bromide (C16TAB) (see picture). This configuration is a surprise because favorable thermodynamics of mixing might suggest that the headgroups should mix at the exterior of micelles.
Details
- Title: Subtitle
- Inverted Micelle‐in‐Micelle Configuration in Cationic/Carbohydrate Surfactant Mixtures
- Creators
- Saikat Das - University of KentuckyWenjin Xu - University of IowaHans‐Joachim Lehmler - University of IowaAnne‐Frances Miller - University of KentuckyBarbara L Knutson - University of KentuckyStephen E Rankin - University of Kentucky
- Resource Type
- Journal article
- Publication Details
- Chemphyschem, Vol.18(1), pp.79-86
- DOI
- 10.1002/cphc.201600908
- PMID
- 27788284
- NLM abbreviation
- Chemphyschem
- ISSN
- 1439-4235
- eISSN
- 1439-7641
- Number of pages
- 8
- Language
- English
- Date published
- 01/04/2017
- Academic Unit
- Occupational and Environmental Health; Iowa Neuroscience Institute
- Record Identifier
- 9984001078702771
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