Characteristics of the bound polymer layer in polymer nanocomposites

In polymer nanocomposites (PNCs), the dynamics of polymers adjacent to the nanoparticles often greatly impacts the properties, performance, and processability. When polymer-nanoparticle interactions are favorable, a bound layer of polymer forms next to the nanoparticle. In the past decade, significant strides were made to develop our understanding of the polymer dynamics in the bound layer. However, a comprehensive study that examines the effects of nanoparticle size, polymer-nanoparticle interaction, and the solvent quality of the bulk polymer solution on the polymer conformation and adsorption dynamics between the bound layer and the surrounding free polymer chains in solution is still missing. In this study, we used classical density functional theory (DFT) calculations and molecular dynamics (MD) simulations to characterize the effect of polymer-nanoparticle interaction, polymer chain length, and nanoparticle size on the polymer conformation and adsorption thermodynamics and dynamics in the bound polymer layer. We expect that our results will have an important impact on our fundamental understanding of limits of kinetics and thermodynamic dispersion of nanoparticles in PNCs.