TRANSPORT PROCESSES AT HYDROPHOBIZED MONTMORILLONITE-MODIFIED ELECTRODES

The transport properties of ionic (Fe(CN)(6)(3-) and Ru(NH3)(6)(3+)) a nd nonionic (p-benzoquinone and nitrobenzene) probes within hydrophobi zed montmorillonite Ams have been investigated by cyclic voltammetric methods. The rate of hydrophobization was one third less than CEC (cat ion exchange capacity). Flms permeability was altered by changing the concentration of the supporting NaCl electrolyte and also by creating different rates of hydrophobization. Structural changes can be interpr eted by non-DLVO ''hydration forces'' theories. Diffusional transport exhibited similar properties in the cases of Fc(CN)(6)(3-) and p-benzo quinone probes, which both have no interactions with the hydrophilic c lay film. Permeation rates were changed in the cases of Ru(NH3)(6)(3+) and nitrobenzene probes. Causes were different, however: electrostati c interactions played their part with Ru(NH3)(6)(3+) ions, while adsor ption and partition made the difference in the case of nitrobenzene.