Em. Kutschmann et al., INTERFACIAL-TENSION OF ALKYLGLUCOSIDES IN DIFFERENT APG OIL/WATER SYSTEMS/, Colloid and polymer science, 273(6), 1995, pp. 565-571
The interfacial performance of pure alkylglucosides (C(8)G(1), C(10)G(
1) and C(12)G(1)) and of technical grade alkylpolyglucoside (APG) surf
actants was investigated in three different water/oil systems (decane,
isopropylmyristate and 2-octyldodecanol). From the dependence of the
interfacial tension on the surfactant concentration below the CMC the
cross-sectional area of the molecules at the decane/water interface wa
s estimated. The plateau values of the interfacial tension at the CMC
(sigma(c)) are independent of temperature and almost independent of ad
ded electrolyte in the decane/water system. The ability of the surfact
ants to lower the oil/water interfacial tension is most pronounced for
the nonpolar oil. The partition coefficient of the surfactant between
oil and water phase (k(c)) was estimated from the CMC and the observe
d break point of the interfacial tension after equilibration of the tw
o phases. In decane/water, k(c) is nearly zero for all surfactants stu
died. For the polar oils, k(c) increases with the chain length of the
surfactant up to k(c) approximate to 10 for C(12)G(1) in octyldodecano
l/water. The values of sigma(c) in the different oil/water systems app
ear to be correlated with k(c) and exhibit a minimum near k(c) = 1.