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Effect of short-chain xanthate on electrostatic interactions and equilibrium thickness of foam films from aqueous solutions of non-ionic frother

✍ Scribed by E. D. Manev; R. J. Pugh


Book ID
104592788
Publisher
John Wiley and Sons
Year
1991
Tongue
English
Weight
493 KB
Volume
17
Category
Article
ISSN
0142-2421

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✦ Synopsis


Abstract

The equilibrium thickness of free thin films produced from aqueous solutions of C~12~(EO)~5~ surfactant (a model frother) with potassium ethylxanthate—KEX (a model collector)—was studied in a wide range of concentrations (from 10^−7^ M to 2 × 10^−2^ M C~12~(EO)~5~; up to 10^−2^ M xanthate).

The xanthate was found to behave in a similar way to common electrolytes and upon its addition the equilibrium film thickness was reduced, apparently due to the suppression of the electrostatic repulsion. However, at higher C~12~(EO)~5~ concentrations (≥10^−5^ M) the equilibrium thickness of the film increased relative to the thickness established with simple inorganic electrolytes at the same ionic strenght. This was explained by the negatively charged xanthate interacting with the non‐ionic frother at the interface and causing a build‐up of charge.

Higher frother concentrations were necessary to produce non‐rupturing films upon increasing the KEX content. This ‘antifoaming’ effect of the xanthate compliments its influence on the electrostatic interactions in the film.