A COMPARATIVE-STUDY OF THE EFFECT OF READY-MADE AND IN SITU-FORMED SURFACTANTS ON INTERFACIAL-TENSION MEASURED BY DROP VOLUME TENSIOMETRY

Interfacial tension between paraffin oil and water was investigated in the presence of surface-active additives using drop volume tensiometr y, Two systems in particular were compared, In the first, sodium linol eate, a ready-made surfactant, was added to the aqueous phase, In the other, the oil phase was acidified with linoleic acid and sodium hydro xide was dissolved in the aqueous phase in order that the same surfact ant be formed in situ via an interfacial reaction, The dynamic interfa cial tension trends exhibited by the two systems were qualitatively co mparable, Under similar conditions in terms of effective surfactant co ncentration and salinity, the equilibrium interfacial tensions observe d were also of a similar magnitude. (C) 1996 Academic Press, Inc.