K. Thalberg et B. Lindman, SEGREGATION IN AQUEOUS SYSTEMS OF A POLYELECTROLYTE AND AN IONIC SURFACTANT, Colloids and surfaces. A, Physicochemical and engineering aspects, 76, 1993, pp. 283-288
Phase diagram studies have been carried out for systems of a polyelect
rolyte and an oppositely charged surfactant in the presence of high co
ncentrations of salt, and for systems of a polyelectrolyte and a surfa
ctant with the same charge. All the systems studied display phase sepa
ration of the segregative type. In the former case, phase separation i
s facilitated by increasing either the alkyl chain length of the surfa
ctant or the molecular weight of the polyelectrolyte. In the latter ca
se, phase separation takes place in the absence of salt but is markedl
y enhanced by salt addition. An increased surfactant chain length and
an increased polyelectrolyte molecular weight facilitates phase separa
tion also in this case. For both types of system the tie lines are mar
kedly skewed, an observation which cannot be explained by Flory-Huggin
gs-type models.