Investigation of Surfactant-Polymer Interactions Using Rheology and Surface Tension Measurements

Jia Yang,Rajinder Pal

doi:10.3390/polym12102302

Abstract

The interactions between surfactants and a drag-reducing polymer were investigated at a low polymer concentration of 500 ppm, using measurements of the rheology and surface activity of surfactant-polymer solutions. A well-known drag-reducing polymer (anionic sodium carboxymethyl cellulose) and five different surfactants (two anionic, two non-ionic, and one zwitterionic) were selected for the interaction studies. The surfactant-polymer solutions were shear thinning in nature, and they followed the power law model. The interaction between the surfactant and polymer had a strong effect on the consistency index of the solution and a marginal effect on the flow behavior index. The surface tension versus surfactant concentration plots were interpreted in terms of the interactions between surfactant and polymer. The critical aggregation concentration (CAC) of the surfactant was estimated based on the surface tension and rheological data. The CAC values of the same charge surfactants as that of the polymer were found to be significantly higher than other combinations of surfactant and polymer, such as non-ionic surfactant/anionic polymer, and zwitterionic surfactant/anionic polymer.

Highlights

Mixtures of polymers and surfactants are used in a variety of applications, such as drug delivery [1,2,3], oil recovery [4], cosmetics, and more [5,6]
The broad objective of this work was to explore the interactions between different surfactants and a polymer, with frictional drag reduction in turbulent flows as the final application
All polymer solutions are shear-thinning, in that the viscosity decreases with the increase in shear rate

Summary

Introduction

Mixtures of polymers and surfactants are used in a variety of applications, such as drug delivery [1,2,3], oil recovery [4], cosmetics, and more [5,6]. The mixtures of polymers and surfactants are used to control the rheology of the solution, and to manipulate surface adsorption of the surfactant. The combination of surfactant and polymer allows easy manipulation and control of the solution rheology. The presence of polymer can speed up the micellization process, resulting in a decrease in the free surfactant concentration. This property is often exploited in skin formulations, as any free surfactant molecules tend to harm the skin and cause irritation

Objectives

Results

Discussion

Conclusion