Partitioning of a polydisperse nonionic surfactant (nonyl phenol ethoxylate) between water and hexane

Abstract

The partitioning behavior of a polydisperse nonyl phenol polyethoxylate of an average ethylene oxide (EO) chain length of 7.3 units (N7.3) between water and hexane has been studied as a function of temperature and total surfactant concentration. A complete analysis of all components of the polydisperse mixture in both the oil and water phases was made using a high-resolution capillary GC column and on column injection. Thermodynamic parameters ΔGW→Oo, ΔHW→Oo and ΔSW→Oo have been obtained for the total surfactant system and the individual components. An ideal mixing, phase separation model has been applied to calculate theoretical partitioning behavior as a function of temperature and surfact..