Microphase separation in cross-linked polymer blends: Efficient replica RPA post-processing of simulation data for homopolymer networks

TL;DR

This paper combines replica theory and molecular dynamics simulations to analyze microphase separation in cross-linked polymer blends, providing an efficient method to interpret neutron scattering data without detailed microscopic assumptions.

Contribution

It introduces an efficient replica RPA post-processing method for simulation data of homopolymer networks, linking theory with experimental scattering results.

Findings

Demonstrates microphase separation in polymer networks

Provides structure function data with intrinsic length scales

Enables interpretation of neutron scattering without microscopic detail

Abstract

We investigate the behaviour of randomly cross-linked (co)polymer blends using a combination of replica theory and large-scale molecular dynamics simulations. In particular, we derive the analogue of the random phase approximation for systems with quenched disorder and show how the required correlation functions can be calculated efficiently. By post-processing simulation data for homopolymer networks we are able to describe neutron scattering measurements in heterogeneous systems without resorting to microscopic detail and otherwise unphysical assumptions. We obtain structure function data which illustrate the expected microphase separation and contain system-specific information relating to the intrinsic length scales of our networks.