A Mechanisms of Adsorption and Aggregation

There are a number of mechanisms by which surface-active solutes may adsorb onto solid substrates from aqueous solution. In general, adsorption of surfactants involves single ions (Kolbel, 1959 Griffith, 1967) rather than micelles (Chapter 3). 

FIGURE 2-6 Ion pairing. Reprinted with permission from M. J. rosen, J. Am. Oil Chem. Soc. 52, 431 (1975). 

Adsorption by Polarization of n Electrons. Occurs when the adsorbate contains electron-rich aromatic nuclei and the solid adsorbent has strongly positive sites. Attraction between electron-rich aromatic nuclei of the adsorbate and positive sites on the substrate results in adsorption (Snyder, 1968). 

FIGURE 2-8 Adsorption via Lewis acid-Lewis base interaction. 

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