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Transport Properties of Ibuprofen Encapsulated in Cyclodextrin Nanosponge Hydrogels: A Proton HR-MAS NMR Spectroscopy Study
Published on: August 15, 2016
Inclusion complexes between beta-cyclodextrin and a Gemini surfactant in aqueous solution: an NMR study
Andrés Guerrero-Martínez1, Gustavo González-Gaitano, Montserrat H Viñas
1Departamento de Química-Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040, Madrid, Spain.
The Journal of Physical Chemistry. B
|July 14, 2006
Summary
Beta-cyclodextrin (beta-CD) forms 1:1 and 2:1 complexes with gemini surfactants, influencing micellization. The surfactant
Area of Science:
- Supramolecular Chemistry
- Colloid and Surface Science
Background:
- Gemini surfactants exhibit unique properties due to their structure.
- Beta-cyclodextrin (beta-CD) is a cyclic oligosaccharide capable of forming inclusion complexes.
Purpose of the Study:
- To characterize the gemini surfactant bis(dodecyl dimethylammonium)diethyl ether dibromide (12-EO(1)-12).
- To investigate the effects of beta-cyclodextrin complexation on gemini surfactant micellization.
Main Methods:
- Proton Nuclear Magnetic Resonance ((1)H NMR) spectroscopy.
- Diffusion-Ordered NMR (DOSY) experiments.
- 2D Rotating-Frame Overhauser Enhancement Spectroscopy (ROESY).
Main Results:
- Characterization of the binary system (gemini surfactant alone) including critical micelle concentration (cmc) and aggregation number.
- Identification of 1:1 and 2:1 (beta-CD:gemini) complex formation in the ternary system.
- Determination of stability constants and hydrodynamic radii of the complexes.
- Observation that beta-CD modifies cmc, primarily indicating 2:1 complex formation.
- Surfactant chemical shifts suggest complexes do not participate in micelles.
- ROE enhancements reveal differential binding of hydrocarbon chains to beta-CD based on stoichiometry.
Conclusions:
- Beta-cyclodextrin significantly influences gemini surfactant micellization through complex formation.
- The stoichiometry of beta-CD:gemini complexation dictates the binding mode of the surfactant's hydrocarbon chains.
- Understanding these interactions is crucial for designing advanced surfactant systems.
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