Morphology and Dynamics of Polymer Nanocomposites for Varying Polymer Filler Interactions

In this paper, we explore the thermodynamic and dynamic properties of polymer nanocomposites using stochastic molecular dynamics simulation in the canonical ensemble. One of the major parameters that determines the properties of nanocomposites is the filler-monomer interfacial interaction strengths. By varying the interaction strengths as well as temperature of the system we could capture the dynamical response of the system from a fluid-fluid to bridging induced 'network' states The structural properties when analyzed show a strongly networked 'solid-like' transition which has been augmented using dynamical analysis. Calculations show the slowing down of nanoparticle diffusion in the network phase due to 'jamming' of the nanoparticles. At certain parameter range, the equilibrium stress-stress autocorrelation function does not decay confirming the existence of 'solid-like' behavior. The change in mechanical properties is supported by the morphological observations.