Accurate Measurements of the Chemical Potential of Polymeric Systems by Monte-Carlo Simulation

TL;DR

This paper introduces a novel Monte-Carlo simulation technique for accurately measuring the chemical potential in polymer systems, especially effective for large chains and dense environments.

Contribution

A new Monte-Carlo method utilizing a ghost polymer and expanded ensemble to estimate chemical potential in polymer models, improving accuracy for large and dense systems.

Findings

Effective for large chain lengths and high densities

Demonstrated precision through finite-size correction calculations

Implemented within the bond fluctuation model

Abstract

We present a new Monte-Carlo method for estimating the chemical potential of model polymer systems. The method is based upon the gradual insertion of a penetrable `ghost' polymer into the system and is effective for large chain lengths and at high densities. Insertion of the ghost chain is facilitated by use of an expanded ensemble in which weighted transitions are permitted between states characterising the strength of the excluded volume and thermal interactions experienced by the ghost chain. We discuss the implementation and optimisation of the method within the framework of the bond fluctuation model, and demonstrate its precision by a calculation of the finite-size corrections to the chemical potential.