Multi-Scale Simulations of Thermodynamics and Transport in Polymeric, Colloidal, and Surfactant Self-assembling Materials

Continuum-level thermodynamic and transport properties relevant to long time and length scales can now be computed from molecular-scale interactions using multi-scale molecular dynamics (MD) simulations and Brownian dynamics (BD) simulations, along with biasing methods, such as umbrella sampling, and forward flux sampling. We demonstrate the power of these methods by computing the dynamics and rheology of “polymer-like” worm-like surfactant solutions and colloid-polymer mixtures used in consumer and industrial products, namely shampoos and paints. The complex structures and rheology of these fluids require multi-scale modeling that include atomistic and coarse-grained molecular simulations, as well as colloidal scale simulations, and model-reduction schemes to connect commercially important rheological properties to chemical composition. We also compare the predicted results to experimental data, and extract information, that is unavailable, or not easily available, from experiments.