Topology, Length Scales and Energetics of Surfactant Micelles

TL;DR

This study uses coarse-grained molecular dynamics to analyze surfactant micelles, revealing how their structure and energetics influence viscosity and enabling the first reliable prediction of micelle end-cap energy.

Contribution

It introduces a novel algorithm for micelle contour tracking and provides new insights into micelle morphology, energetics, and their effects on viscosity.

Findings

Branched micelle structures affect viscosity behavior.

End-cap energy of micelles can be reliably predicted from simulations.

Microstructural features like contour length and mesh size are quantified.

Abstract

We investigate the morphology and energetics of a self-associating model cationic surfactant in water using coarse-grained molecular dynamics simulations. We develop an algorithm to track micelles contours and quantify various microstructural features, such as contour length, persistence length, mesh size, and entanglement-length. We demonstrate that branched and multiconnected structures govern the anomalous dependence of zero-shear viscosity on salt concentration. We predict reliably the end-cap energy of micelles, for the first time, from simulations.