Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 4, pp. 636−640.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
I.I. Goncharik, F.F. Mozheilo, A.I. Voitenko, O.A. Kudina, 2010, published in Zhurnal Prikladnoi Khimii, 2010, Vol. 83, No. 4,
OF SYSTEMS AND PROCESSES
Effect of Inorganic Electrolytes and Aliphatic Alcohols
on the Foaming Capacity of Sodium Salts of Carboxylic Acids
I. I. Goncharik, F. F. Mozheilo, A. I. Voitenko, and O. A. Kudina
Institute of General and Inorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
Received March 19, 2009
Abstract—Foaming and stabilizing capacities of sodium salts of carboxylic acids (lauric, myristic, palmitic) in
the presence of aliphatic alcohols (hexanol, butanol) and inorganic electrolytes was studied.
One of factors determining the efﬁ ciency of surfactants
is their ability to form foams. Sodium salts of carboxylic
acids (sodium soaps) are widely used as foaming agents,
both in the individual state and with various additives.
For example, numerous technological processes and,
in particular, mineral dressing by ﬂ otation use mixtures
of sodium soaps with aliphatic alcohols, which are more
active than individual substances. Therefore, it was of
interest to study the foaming of binary aqueous solutions
of sodium soaps and aliphatic alcohols.
Because foaming occurs in many cases in the
presence of inorganic electrolytes, it was of interest
to also examine their effect on the formation of foams
produced with sodium salts of carboxylic acids (lauric,
myristic, palmitic) both in solutions of individual
sodium soaps and in mixtures with aliphatic alcohols.
Sodium, potassium, calcium, magnesium, and aluminum
chlorides, as well as sodium phosphate, were used as
Previously , the foaming capacity of individual
sodium salts of carboxylic acids (butyric, pentanoic,
octanoic, lauric, myristic, palmitic) has been studied.
It was found that their foaming capacity depends on
the chain length in the homological series of saturated
sodium salts of carboxylic acids and on reagent
concentrations. An increase in the hydrocarbon chain
length in the homologous series of soaps ﬁ rst leads to
an increase in their foaming activity, which reaches
a maximum for sodium myristate.
It was shown that raising the concentration of soaps
in an aqueous system favors an increase in the height
of the foam column, which reaches a maximum at the
critical micelle concentration (CMC) and then decreases.
The reason is that the formation of an adsorption layer
at the liquid–gas interface in complete at around the
CMC and this adsorption layer acquires the maximum
mechanical strength, and just this circumstance causes
It has been shown  that foaming of surfactant
solutions begins at a volume concentration corresponding
to the saturation of the adsorption layer, c
. It is also
known that the saturation of the adsorption layer is
reached in the presence of electrolytes at lower volume
concentrations of surfactants. It has been demonstrated
 that the decrease in c
with increasing concentration
of the counter ion for micelle-forming surfactants is
described by the equation
= –a log c
i.e., an increase in the electrolyte concentration makes
lower the surfactant concentration at which the foaming
The effect of electrolytes on the c
and CMC is