Frothing Behavior of Nonionic Surfactant Solutions in the Presence of Organic and Inorganic Electrolytes.

The influence of inorganic salts (KCl, KBr, NaI, KI) and organic salts, tetrapentyl ammonium bromide (TPeAB) and tetrabutyl ammonium bromide (TBuAB), on the decay of a foam column from aqueous solutions of octaethyleneglycol mono-n-decylether (C(10)E(8)) has been investigated. The salt concentration in all cases was maintained constant (0.01 M). The results from the measurements of the foam decay rates indicate that, of the inorganic electrolytes, KBr is a foam destabilizer, KCl does not influence the froth stability, and NaI and KI act as foam stabilizers. Both TBuAB and TPeAB generate greater initial quantities of foam. Concurrently, both organic salts accelerate the destruction of the foam in the initial stage of drainage, the effect of TBuAB being stronger. It was established also that in the later stage of drainage, where black films form (here C(10)E(8) bulk concentration is 5 x 10(-4) M and its C(bl)=10(-4) M), TPeAB acts as foam destabilizer, while TBuAB does not influence the foam stability. Copyright 2001 Academic Press.