S. Backlund et al., AGGREGATION STUDIES IN ALKANOIC ACID-ALKYLAMINE-WATER SYSTEMS, Colloids and surfaces. A, Physicochemical and engineering aspects, 123, 1997, pp. 125-133
Alkylamines show amphiphilic properties such as self-association in po
lar solvents and accumulation at interfaces. However, their complexati
on with alkanoic acids changes drastically their colloidal properties.
Phase equilibria at different temperatures in the systems hexanoic ac
id-hexylamine-water, heptanoic acid-heptylamine-water and octanoic aci
d-octylamine-water were determined in order to elucidate the structure
in the isotropic solution phases. Densities, surface tensions, electr
ical conductivities and viscosities were measured at 298.2 K. Self-dif
fusion coefficients were also determined both in the acid- and in the
amine-rich part of the phase diagram in order to confirm if a componen
t is confined to closed aggregates. The aim of this study was to contr
ibute to a better understanding of the complexation in relation to the
properties of catanionic surfactants.