题 目：Dynamics and Rheology of Entangled Polymer Melts: Multiscale Modelling and Simulations

报告人： Dr. Zuowei Wang 
School of Mathematical and Physical Sciences
University of Reading

Abstract
 

Theoretical works on entangled polymers have been for over forty years primarily based on the tube or reptation model, which is subject to continuous examination and improvement. In this talk, we will present our multiscale theoretical and simulation works on entangled linear and branched polymer melts, with particular interests on testing and applying tube theories in describing their dynamical and rheological behaviour. We start with using fine-grained molecular dynamics and coarse-grained slip-springs model simulations to explore the segmental dynamics of entangled linear polymers over a wide range of chain lengths and time scales, and compare the simulation results with tube model predictions and recent experimental measurements. Then we present an updated version of the tube-based hierarchical model, which allows the prediction of the linear rheology of general mixtures of polydisperse branched polymers. A detailed overview of the performance of this and some other tube-based computational models confirms their prediction power, but also indicate that microscopic understandings of entanglement dynamics are still highly desired for developing quantitative theories without ad hoc assumptions. Anyhow, at this stage, one can take advantage of the existing multiple models and incorporate them into the so-called multimodel superensemble model (MMSE) to generate a consensus forecast that can easily outperform the best constituent model.