EQUILIBRIUM AND KINETIC-PROPERTIES OF ALKYLPYRIDINIUM SULFATE MICELLES

Equilibrium and kinetic measurements on tetradecyl- and pentadecylpyridinium sulfate micelles have been carried out. The value of the degree of counter ion dissociation alpha is seen to be highly dependent on the method used for its determination. The critical micelle concentrations and the mean aggregation numbers are close to those of the corresponding bromides. The fast and slow relaxation times for the two substances were also measured and the different values of alpha were used for the calculation of the parameters obtainable from the relaxation times. The rate constants and the width of the micelle size distributions determined from the fast relaxation time are seen to be rather insensitive to the value of alpha , while the parameters characterizing the submicellar aggregates are highly dependent on the degree of dissociation. Furthermore, an explanation is given for the very different concentration dependences of the slow relaxation time for the alkylpyridinium sulfate and sodium alkyl sulfate micelles.