Effect of aggregation on the reactivity of dodecylammonium propionate in organic solvents
| Autor: | Bernard Valeur, Eric Monnier |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
chemistry.chemical_classification
Chemistry Vapor pressure osmometry Kinetics Inorganic chemistry Surfaces Coatings and Films Electronic Optical and Magnetic Materials Biomaterials Chemical kinetics Colloid and Surface Chemistry Reaction rate constant Pulmonary surfactant Propionate Reactivity (chemistry) Equilibrium constant |
| Zdroj: | Journal of Colloid and Interface Science. 150:473-485 |
| ISSN: | 0021-9797 |
| Popis: | Dodecylammonium propionate (DAP) is a surfactant that undergoes sequential self-association in organic solvents. Its reactivity as a nucleophilic agent depends on the aggregation state. The kinetics of esterolysis of three allophanic esters and p-nitrophenylacetate were studied in benzene and 1,2-dichloroethane as a function of surfactant concentration. After demonstrating by FTIR experiments that the monomeric form of DAP consists of dodecylamine and propionic acid, various kinetics models were developed. Excellent agreement of the experimental data was found with a model in which two rate constants, k1 (for the monomeric form) and ka (for a surfactant molecule in an aggregate, whatever the size of the aggregate), are considered. Analysis of the data also provides the equilibrium constant K of self-association. The validity of the kinetic model is further supported by the fact that the value found for K in benzene is the same for the four esters and in agreement with the value reported in the literature (determined by vapor pressure osmometry). Furthermore, this agreement means that the self-association of a surfactant like DAP can be studied by chemical kinetics. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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