PARTITIONING OF ETHOXYLATED ALKYLPHENOL SURFACTANTS IN MICROEMULSION-OIL-WATER SYSTEMS - PART II - INFLUENCE OF HYDROPHOBE BRANCHING

Ethoxylated alkylphenol surfactants fractionation between oil and wate r is best studied in three-phase so-called optimum formulation systems , in which a microemulsion is in equilibrium with both oil and water e xcess phases. The partitioning is found to be slightly affected by the structure of the surfactant hydrophobe. It is found that the more the branching the more the surfactant tends to partition into the water p hase, and less into the oil phase. The study includes data for linear and branched alkylate species as well as multiple alkyl group species. (C) 1998 Elsevier Science B.V.