A conductimetric study of the association between cyclodextrins and surfactants—application to the electrochemical study of a mixed aqueous system: Substrate, cyclodextrin, surfactant
| Autor: | Eric Saint Aman, Denis Serve |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
chemistry.chemical_classification
Aqueous solution Cyclodextrin Inorganic chemistry Substrate (chemistry) Surfaces Coatings and Films Electronic Optical and Magnetic Materials Biomaterials Colloid and Surface Chemistry Pulmonary surfactant Radical ion chemistry Critical micelle concentration Fluorocarbon Alkyl |
| Zdroj: | Journal of Colloid and Interface Science. 138:365-375 |
| ISSN: | 0021-9797 |
| DOI: | 10.1016/0021-9797(90)90219-e |
| Popis: | The associations between the α- or β-cyclodextrin (CD) and some surfactants (alkyl sulfates, C 6 -C 12 ; fluorocarbon surfactants, C 3 -C 9 ) have been studied by conductimetry and the corresponding association constants have been determined. The association process involves the inclusion phenomena and the critical micelle concentration is shifted to the higher concentrations. The surfactant and the CD form mainly a 1:1 complex when the chain length is smaller than that of C 10 , except for the fluorocarbon surfactants which form 1:2 (surfactant:CD) complexes with α-CD. The interactions increase with the surfactant size up to the CD cavity saturation. The electrochemical study of a hydrophobic substrate, 3-(10-phenothiazinyl) propionic acid, in the presence of β-CD and surfactant, has confirmed the conductimetric results. The more hydrophobic environment of the cavity in the surfactant-β-CD complex allows the formation of a 1:1:1 substrate-surfactant-β-CD complex, which is stronger than the 1:1 substrate-β-CD complex. The stability of the electrogenerated radical cation is significantly improved in surfactant solutions and more slightly improved in β-CD solution. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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