Effect of ethoxylated nonyl-phenols on interfacial rheological properties of oil/water systems

Interfacial rheological properties of different Hungarian crude oil/water systems were determined in wide temperature and shear rate range and in presence of ethoxylated nonyl-phenols with ethoxy group number between 10 and 40. The fundamental conclusion of the experimental results is that the interfacial viscosity, the non-Newtonian flow behavior and the activation energy of the viscous flow drastically decrease in presence of non-ionic surfactants. Modification of these interfacial rheological properties increase with decreasing ethoxy group number and increasing tenside concentration and temperature. The most radical change was observed in presence of NPEO10. As a summary it was evidenced that the interfacial rheology is an efficient and powerful detection technique, which may enhance our knowledge on formation, structure, properties and behavior of interfacial layers formed in oil/water systems. Thus, similar studies will probably accelerate the progress significantly not only in oil recovery but also in all areas of colloid science and technology.