NMR-STUDIES ON MICELLAR SOLUTIONS OF PYRIDINIUM OCTYLHYDROGEN PHOSPHATE

For surfactant concentrations between 0. 07 mole/liter (CMC) and 2 moles/liter the pyridinium octylhydrogen phosphate forms a micellar solution which has been investigated by **1H, **2H, **3**1P, and **1**3C NMR in wide frequency ranges. The self-diffusion coefficients of the components of this solution have been determined by pulsed gradient spin-echo experiments on protons, showing in particular a rapid decrease of the monomer concentration above the CMC and a binding coefficient of 0. 7 for the pyridinium counterions. The aggregate size has been obtained from proton longitudinal relaxation experiments at frequencies ranging from 6 to 500 MHz. The order parameter profile and the rate of segmental motions of the micellized amphiphile have been determined by **3**1P and **1**3C relaxation and compared to the sodium octylhydrogen phosphate.