Titration of fatty acids solubilized in catonic, nonionic and anionic micelles: Theory and experiment.
Author
Summary, in English
The titration properties of a fatty acid solubilized in different types of micelles, cationic, anionic and nonionic, have been investigated experimentally and theoretically. The solution containing micelles, counterions, and added salt was treated as a dielectric continuum in the Monte Carlo simulations. The dielectric permittivity of the interior of the micelle can have a profound effect on the calculated pK shifts depending on how the dielectric discontinuity is chosen in the model. The simulated results are compared to data from Poisson-Boltzmann calculations and from experiments. The experimentally observed apparent pKa value changes from 7.6 to 4.9 when solubilizing lauric acid in anionic (SDS) and cationic (DoTAC) micelles, respectively. For the nonionic micelle it is found to be approximately 6.6. A significant ion specificity in the pKa value is observed for the DoTAC and DoTAB systems and surprisingly enough both systems show an upward pK shift.
Department/s
Publishing year
2002
Language
English
Pages
3515-3522
Publication/Series
The Journal of Physical Chemistry Part B
Volume
106
Issue
13
Document type
Journal article
Publisher
The American Chemical Society (ACS)
Topic
- Physical Chemistry
- Theoretical Chemistry
Status
Published
ISBN/ISSN/Other
- ISSN: 1520-5207