Dynamic interfacial tension of nonanoic acid/hexadecane/water system in response to pH adjustment

Abstract

The ability to accurately model dynamic interfacial tension offers valuable predictive power in non-equilibrium multiphase systems. In this study, a recently-developed technique was employed to experimentally monitor the interfacial tension during neutralization of the adsorbed nonanoic acid at an oil/water interface. The transient oil/water interfacial tension was successfully obtained during reaction, for more than one hour, by fitting the Young-Laplace equation to the holm meridian. Subsequently, the dynamic data was effectively described by a dynamic model based on the underpinning physical principle: diffusion of hydronium ions. The experimental and modelling methods are applicable to mixtures of alkane/carboxylic acid/water, which are often found in industrial processes.