Coarse-grained simulations of concentration-dependent molecular self-assembly of Polysorbate 80 in water

Surfactant molecules are known to self-assemble into micellar structures due to their amphiphilic nature of interactions with the solvent molecules. This ubiquitous phenomenon has been largely understood through the qualitative description of forces that govern these events. However, computational models that provide an accurate quantitative characterization of the process of micelle formation are still limited. In this study, we develop a coarse-grained computational model for Polysorbate 80 surfactant molecules that captures the phenomenon of aggregation at concentrations ranging from 0.1% to 10% in water. Here, we use a dissipative particle dynamics scheme to describe the interactions between the coarse-grained beads in the system. This computational model is able to reproduce the characteristics of micelle formation with increasing surfactant concentration. Our results demonstrate that despite loss in the degrees of freedom, the coarse-grained model predicts the structural and transport properties of the surfactant system with sufficient accuracy. The presented coarse-grained modeling technique offers a new window to uncover the molecular mechanisms of self-organization in the biophysical systems over a wide range of lengths and time scales.