Layer-charge distribution

Due to its high charge density and homogenous layer charge distribution synthetic fluorohectorite is one of the few available clays suitable for PCH formation. However, even this clay proved to have some disadvantages. Synthetic fluorohectorite is obtained from molten fluxes and is unstable with respect to calcination (partial defluorination) at 350 °C. 

The double layer charge distribution (eq 11) was employed in the derivation of the last equation. 

Figure 1.14. Basal plane spacings of N-alkylammonium complexes with a Vertisol clay fraction and the corresponding layer charge distribution. ...

Wang, J. and Bard, A.J. (2001) Direct atomic force microscopic determination of surface charge at the gold/electrolyte interface - the inadequacy of classical GCS theory in describing the double-layer charge distribution. Journal of Physical Chemistry B, 105, 5217. 

Usually, the main factors governing the adsorption on smectites are concentration or vapor pressure, pH, interlayer cation, layer charge and temperature. Many other factors can also be operative the layer charge distribution [23], pretreatment of the smectites, degree of dispersion [24], presence of salts not only concentration or ionic strength, but also the very nature of the ions [20, 23, 25]. 

The above discussion also applies to the thin double layer systems with surface conductance considered in the previous section. The surface conductance alters the double layer charge distribution, and so it gives rise to double layer distortion. 

From polarization curves the protectiveness of a passive film in a certain environment can be estimated from the passive current density in figure C2.8.4 which reflects the layer s resistance to ion transport tlirough the film, and chemical dissolution of the film. It is clear that a variety of factors can influence ion transport tlirough the film, such as the film s chemical composition, stmcture, number of grain boundaries and the extent of flaws and pores. The protectiveness and stability of passive films has, for instance, been based on percolation arguments [67, 681, stmctural arguments [69], ion/defect mobility [56, 57] and charge distribution [70, 71]. 

On the electrode side of the double layer the excess charges are concentrated in the plane of the surface of the electronic conductor. On the electrolyte side of the double layer the charge distribution is quite complex. The potential drop occurs over several atomic dimensions and depends on the specific reactivity and atomic stmcture of the electrode surface and the electrolyte composition. The electrical double layer strongly influences the rate and pathway of electrode reactions. The reader is referred to several excellent discussions of the electrical double layer at the electrode—solution interface (26-28). 

C. Importance of the Native Charge Distribution for the Integrity of S-Layer Lattices... 

The EDL charge distribution can be modeled by a Poisson-Boltzmann equation (see, e.g., [46]). In many practical cases values for the layer thickness between 1 and 100 nm are obtained [47]. 

The diffuse charge distribution in the semiconductor s surface layer leads to a drastically lower cell capacitance at the semiconductor-electrolyte interface. Typical... 

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