ELECTROCHEMICAL DETECTION OF ANISOTROPIC PROBE DIFFUSION IN THE LIQUID-CRYSTALLINE CESIUM PENTADECAFLUOROOCTANOATE D2O SYSTEM/

Anisotropic diffusion of electroactive probes incorporated into monodo main lamellar phases of 50 wt% cesium pentadecafluorooctanoate (CsPDFO )/D2O has been detected using cyclic voltammetry. The diffusional anis otropy ratios, D(perpendicular-to)/D(parallel-to), were 2.0 for the an ion [Fe(CN)6]4- and 19.3 for the positively charged (ferrocenylmethyl) trimethylammonium ion (FcMTMMA+). Differences in diffusional anisotrop ies for these two probes are attributed to hydrophobic and Coulombic i nteractions between the probe species and the ordered phase. Small tim e scale dependencies in the diffusion coefficients of [Fe(CN)6]4- in t he lamellar phase were observed, possibly due to a perturbation of the bulk order by the electrode surface.