Formation of middle-phase microemulsions using surfactants derived from a renewable resource: Ethoxylated tall oils

Abstract

The range of salinities over which a large number of multicomponent systems containing ethoxylated tall oils or tall-oil derivatives form middle-phase microemulsions was determined. n-Octane and n-decane were used as the hydrocarbons; 2 methyl-l-propanol and 2-butanol as the cosurfactants. It is possible, with an appropriate choice of surfactant, to produce systems with optimal salinities from 0 to ca. 17 wt% NaCl. Phase volume diagrams are presented for 24 of the systems investigated; interfacial tension measurements for selected systems show tensions in the millidyn/cm range at the optimal salinities.