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Holzheu, Stefan ; Behrends, Thilo ; Herrmann, Reimer:
Determination of Distribution Ratios of Aromatic Compounds between Aqueous Solution and Surfactant-Covered Silica by a Chromatographic Method.
In: Scamehorn, John F. ; Harwell, Jeffrey H.
(Hrsg.):
Surfactant-Based Separations : Science and Technology. -
Washington, DC
: American Chemical Society
,
2009
. - S. 314-328
. - (ACS Symposium Series
; 740
)
ISBN 9780841236189
DOI: https://doi.org/10.1021/bk-2000-0740.ch019
Abstract
The knowledge of distribution constants between aqueous solution and surfactant covered solid phases is important for the understanding of the process of adsolubilization and for applications based on this process. In this work equilibrium constants of 26 aromatic compounds were determined by a chromatographic method as a function of pH and of the adsorption density of hexadecyltrimethylammonium-bromide (HDTMAB) on silica. The dependency of the retention times on surfactant adsorption changes with increasing HDTMA coverage and is modified by pH. The changes can be explained by the transition of electrostatically driven surfactant adsorption to hydrophobic aggregation. Formation of core regions in the surfactant aggregates due to hydrophobic aggregation favors adsolubilization of non-polar compounds. At the same time equilibrium constants of polar organic compounds decrease because of the reduced interfacial area per surfactant molecule. Facilitated deprotonation of carboxylic and phenolic groups at higher pH results in an increasing adsolubilization efficiency when hydrophobic aggregation is considered and superequivalent adsorption is enabled.
Weitere Angaben
| Publikationsform: | Aufsatz in einem Buch |
|---|---|
| Begutachteter Beitrag: | Ja |
| Institutionen der Universität: | Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Geowissenschaften > Lehrstuhl Hydrologie |
| Titel an der UBT entstanden: | Ja |
| Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Eingestellt am: | 21 Nov 2023 09:27 |
| Letzte Änderung: | 21 Nov 2023 09:27 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/87825 |