Surfaces of aqueous electrolytes

It is a well-known fact that bubbles produced by mechanical force in electrolyte solutions are much smaller than those in pure water. This can be explained by reduction of the rate of bubble coalescence due to an electrostatic potential at the surface of aqueous electrolyte solutions. Thus, k a values in aerated stirred tanks obtained by the sulfite oxidation method are larger than those obtained by physical absorption into pure water, in the same apparatus, and at the same gas rate and stirrer speed [3]. Quantitative relationships between k a values and the ionic strength are available [4]. Recently published data on were obtained mostly by physical absorption or desorption with pure water. 

Returning to traditional methods of investigation, the double layer at the surface of aqueous electrolytes described above by computer simulation and spectroscopic methods has long ago been probed by measuring the surface potential of the solutions relative to that of pure water (Randles 1957, 1977 Jarvis and Scheiman 1968). The... 

Monolayers at the surface of aqueous electrolyte solutions may be useful models for polyelectrolytes [11, 14] and for biological membranes [15]. The average distribution of the fixed charges, limited to a plane near the interface, is well defined and the variation of the interfacial potential may be measured. Thus the surface potential-pH plots resemble those of acid-base titrations of polyacids [16, 19]. From these curves the degree of dissociation of the fatty acid in the monolayer may be deduced [17, 18]. 

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