Surface charge density silver electrodes

FIG. 8. Frequency shift versus surface charge density on gold and silver electrodes in 0.1 M solution of LiC104 in water (a) and in butanol (b). (Fig. 8a from Ref 98.)... 

While in the mentioned work on PABA on a charged silver electrode also the adsorption degree of the molecules was controlled by surface charge, Lahann et al. showed a concept in which molecules immobilized as a low-density self-assembled monolayer on a gold surface were electrically stimulated to undergo conformational transitions between a hydrophilic and a hydrophobic state (Lahann et al., 2003). Such a surface wetting switch may then be used to immobilize, for example, enzymes, as was discussed in the previous section. This is an example of switching both the orientation and the activity of adsorbed molecules. 

Recently, Toney et al. [140] published the results of X-ray reflectivity measurements on dilute aqueous sodium fluoride solutions near positively and negatively charged silver electrodes with (111) surface geometry. The analysis shows an oscillatory density profile with three or four density maxima near the interface, qualitatively similar to the results in Fig. 7. They also found a very large shift of the distance of the first... 

Even in dilute electrolyte solutions, many properties of water are strongly modified in the immediate vicinity of a charged interface, especially its density. This effect has chiefly been studied by electrochemists interested in charged metallic surfaces water close to a silver electrode bearing a surface charge of 0.25 Coulomb/m reaches a density of 2.0 i.e., close to that of... 

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