Adsorption electro-diffusion control

This is an important difference with the cases of adsorption under diffusion and electro-diffusion control, for which Ao(t) oc cf. Equations 4.70, 4.76, and 4.78. Thus, a test to check whether or not the adsorption occurs under purely barrier control is to plot data for In[Ao(t)] versus t and to check if the plot complies with a straight Une. 

D. Electro-Diffusion Control (Adsorption of Ionic Surfactants)... 

Many practical processes (foaming, emulsification, dispersing, wetting, washing, solubilization) are influenced by the rate of adsorption from surfactant solutions. This rate depends on whether the adsorption takes place under diffusion, electro-diffusion, barrier, or convective control. The presence of surfactant micelles, which serve as carriers, and a reservoir of surfactants can strongly accelerate the kinetics of adsorption see Secs. 

The kinetics of stabilization must match the kinetics of aggregation. While ion diffusion and adsorption is fast (electrostatic stabilization), the diffusion and adsorption of polymers (steric stabilization) is slow and may be a limiting factor which can only be overcome by applying high polymer concentrations. The stability of the electrostatic stabilized suspension in moderately fast processes can for example be monitored and controlled in-line by modem electro-acoustic techniques [13]. 

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