Multiscale Modeling of Binary Polymer Mixtures: Scale Bridging in the Athermal and Thermal Regime

TL;DR

This paper introduces a multiscale modeling approach that efficiently links atomistic and coarse-grained simulations to predict the static structure of binary polymer blends, incorporating thermal effects through an effective chi parameter.

Contribution

A novel multiscale modeling procedure combining simulations at different length scales with inverse mapping for binary polymer mixtures, including thermal fluctuations.

Findings

Efficient calculation of static structural properties of polymer blends.

Validation of the coarse-grained approach against full atomistic simulations.

Extension of the method to include thermal fluctuations via an effective chi parameter.

Abstract

Obtaining a rigorous and reliable method for linking computer simulations of polymer blends and composites at different length scales of interest is a highly desirable goal in soft matter physics. In this paper a multiscale modeling procedure is presented for the efficient calculation of the static structural properties of binary homopolymer blends. The procedure combines computer simulations of polymer chains on two different length scales, using a united atom representation for the finer structure and a highly coarse-grained approach on the meso-scale, where chains are represented as soft colloidal particles interacting through an effective potential. A method for combining the structural information by inverse mapping is discussed, allowing for the efficient calculation of partial correlation functions, which are compared with results from full united atom simulations. The structure of several polymer mixtures is obtained in an efficient manner for several mixtures in the homogeneous region of the phase diagram. The method is then extended to incorporate thermal fluctuations through an effective chi parameter. Since the approach is analytical, it is fully transferable to numerous systems.