(521h) Systematic and Many-Chain-Simulation-Free Coarse Graining of Polymer Melts: Structure-Based Coarse Graining of the Kremer-Grest Model

Our group recently proposed the systematic and simulation-free strategy for coarse graining of polymeric systems [1,2], where the well-developed polymer reference interaction site model (PRISM) theory, instead of the many-chain molecular simulation (MCMS), is used to obtain the structural and thermodynamic properties of both the original and coarse-grained (CG) systems. Our strategy is much faster than those using MCMS, thus effectively solving the transferability problem of coarse graining. It also avoids the problems caused by the finite-size effects and statistical uncertainties of MCMS, particularly for the original system, which are the reasons why its coarse graining is needed. Taking various original systems of continuous Gaussian chains with ideal conformations and the Dirac d-function interactions due to their simplicity, we have applied our strategy to the structure-based coarse graining of homopolymer melts [1], binary polymer blends [2], and diblock copolymers, as well as to the relative-entropy-based coarse graining of homopolymer melts [3], in order to demonstrate its advantages. Here we apply our strategy to the structure-based coarse graining of the well-known Kremer-Grest model for homopolymer melts, where the self-consistent PRISM theory is used to avoid the assumption of ideal-chain conformations in the original system. This paves the way to quantitatively applying our strategy to more realistic polymers and their multiscale modeling.

[1] D. Yang and Q. Wang, J. Chem. Phys. 142, 054905 (2015).

[2] Q. Wang, Polymer 117, 315-330 (2017).

[3] D. Yang and Q. Wang, Soft Matter 11, 7109 (2015).