The effect of surfactant structure on the rate of oil solubilization into aqueous surfactant solutions

Abstract

AbstractReduced washing temperatures decrease the rate of the various processes in a laundry cleaning cycle. This implies that fast acting detergents are needed if acceptable washing performance is to be maintained within a realistic period of time. An important factor is the rate of oily soil removal which, among other things, is a function of the molecular structure of the surfactants used in the detergent. To support the selection of proper surfactants we have established relationships between chemical structure and rate of oil solubilization for a series of alkylarenesulfonates with various alkyl chain lengths, points of attachment of the phenyl group at the alkyl chain, and aromatic substitution patterns. It is shown that oil solubilization kinetics are very sensitive to the geometry of the surfactant structure: for a set of isomeric alkylarenesulfonates the rate of oil solubilization can be made to by more than an order of magnitude by changing the substitution pattern around the aromatic ring. The results offer a predictive tool for the design of molecules with the proper surface activity under a wide set of experimental conditions.