high voltage insulating materials (11). In all these applica-Dye molecules are frequently used to determine the specific tions, the interface between organic compound and filler can surface area and the ion exchange capacity of high-surface-area play an important role in the resulting mechanical properties materials such as mica. The organic molecules are often considered and the chemical and environmental stability of the composto be planar and to adsorb in a flat orientation. In the present ite systems. Thus the nature of the bond between polymers study we have investigated the orientation and electronic structure (organic species) and mica is of significant importance, and of crystal violet (CV) and malachite green (MG) on muscovite possibilities for the modification of mica surfaces are of mica, prepared by immersing the substrates for extended periods considerable interest for technological applications. Hence into aqueous solutions of the dyes of various concentrations. The the configuration in the adsorbed state as well as the orienta-K / ions of the mica surface are replaced by the organic cations via ion exchange. X-ray photoelectron spectroscopy reveals that tion of organic molecules on these surfaces play a crucial only one amino group is involved in the interaction of CV and role in both fundamental and applied sciences.
MG with the muscovite surface, i.e., certain resonance structures
The orientation of adsorbates is of particular interest in are abolished upon adsorption. With near edge X-ray absorption view of the determination of the specific surface area of fine structure spectroscopy a significant tilt angle with respect to silicates, powders or flakes. Among other techniques such the surface was found for all investigated species. A flat orientaas the BET method, cationic organic dye molecules are used tion, as has often been proposed before, can effectively be ruled to determine the specific surface area. Dissolved in water, out. Hence, our results are in marked contrast to the often quoted the organic cations replace the potassium cations of the susorientation and suggest that the specific surface areas determined pended mica (2, 5). The dyes are generally considered as with dyes may, in general, be overestimated. ᭧ 1998 Academic Press planar molecules that adsorb in a flat orientation (12-15).