Molecularly Informed Field Theories from Bottom-up Coarse-Graining

Polymer formulations possessing mesostructures or phase coexistence are challenging to simulate using atomistic particle-explicit approaches due to the disparate time and length scales, while the predictive capability of field-based simulations is hampered by the need to specify interactions at a coarser scale (e.g., chi-parameters). To overcome the weaknesses of both, we introduce a bottom-up coarsegraining methodology that leverages all-atom molecular dynamics to molecularly inform coarser field-theoretic models. Specifically, we use relative-entropy coarse-graining to parametrize particle models that are directly and analytically transformable into statistical field theories. We demonstrate the predictive capability of this approach by reproducing experimental aqueous poly(ethylene oxide) (PEO) cloud-point curves with no parameters fit to experimental data. This synergistic approach to multiscale polymer simulations opens the door to de novo exploration of phase behavior across a wide variety of polymer solutions and melt formulations.

Automated summary

This method leverages all-atom molecular dynamics to inform coarser field-theoretic models, successfully predicting experimental PEO cloud-point curves without fitting parameters to experimental data. This multiscale simulation approach opens up new avenues for studying phase behavior across different polymer solutions and melt formulations.