In situ characterization of electrochemical processes at the solid/liquid interface using the quartz crystal microbalance

The electrochemically modulated adsorption of four ferrocene surfactants is described. The adsorption and desorption of these redox surfactants are studied as functions of alkyl chain length and concentration of the surfactant. The redox surfactants are studied in situ using Electrochemical-Quartz Crystal Microbalance (EQCM) techniques. The reduced forms of the surfactants are shown to be more strongly adsorbed than the oxidized ferricenium forms. The more positive formal potentials of the adsorbed forms relative to those in solution as well as the adsorption isotherms for each allow for calculation of the adsorption energies of both forms of each surfactant. The formal potentials for the redox surfactants in micelles and as monomers is shown to be a function of the ;The electrochemical polymerization of thin films of a difunctional ferrocene is achieved by disulfide coupling, induced by electrocatalyzed oxidation of thiol groups. The EQCM technique is used to monitor the total amount of poly(1-1;The synthesis and monolayer formation of three different viologen surfactants that are irreversibly bound to gold electrodes through thiol or disulfide groups are reported. The EQCM technique will be shown to be an excellent method to determine ion and solvent transport within the assembled monolayer. Ion mobility within the monolayer will be shown to be very influential in the electron transfer rate.