Spatially resolving energy dissipation in molecular dynamics of polymer nanocomposites

Compared to nanoparticle-free elastomers, elastomeric nanocomposites have a larger toughness and feature an unusual mechanical response. This reinforcement is linked to an enhanced ability of nanocomposites to dissipate energy. Despite these materials' prevalence, the molecular mechanisms controlling this reinforcement remain poorly understood. In an effort to resolve this, here we describe a new approach to quantifying the location of dissipation in molecular dynamics simulations of nanoparticle-filled melts of bead springs. We describe analyses of our data that differentiate between multiple hypothesized mechanisms of enhanced dissipation in elastomeric nanocomposites. A better understanding of the origins of enhanced dissipation will lead to better lifetime prediction of many industrial products and enable new materials combining toughness with targeted functionalities such as high or low thermal or electrical conductivity, permeability, or ion conductivity - advances relevant to energy storage, thermal management, and separations.