A self-diffusion study of poly(ethylene-oxide) alkyl alcohols

The self-diffusioncoefficients of HDO and some surfactants in aqueous mixtures at different concentrations, below the critical micelle concentration, have been determined by means of the NMR, spin-echo pulsed field gradient method. The surfactant solutes chosen were ethylene glycol-pentyl alcohol (diethylene glycol- pentylalcohol, ethylene glycol-hexyalcohol, diethylene glycol-hexyl alcohol, tri- ethylene glycol-hexyl alcohol, tetraethylene glycol-hexyl alcohol, pentaethylene glycol-hexyl alcohol). The interactions in solution are studied by analyzing the solute self-diffusion coefficients extrapolated to infinite dilution. These values are comparedwith those of 1-alkanols.The slope of the self diffusioncoefficients vs. the solute concentration are correlated with the microscopic friction coeffi- cients. A model for interpreting the experimental data is suggested.