Communication: One size fits all: Equilibrating chemically different polymer liquids through universal long-wavelength description

Abstract

Mesoscale behavior of polymers is frequently described by universal laws. This physical property motivates us to propose a new modeling concept, grouping polymers into classes with a common long-wavelength representation. In the same class, samples of different materials can be generated from this representation, encoded in a single library system. We focus on homopolymer melts, grouped according to the invariant degree of polymerization. They are described with a bead-spring model, varying chain stiffness and density to mimic chemical diversity. In a renormalization group-like fashion, library samples provide a universal blob-based description, hierarchically backmapped to create configurations of other class-members. Thus, large systems with experimentally relevant invariant degree of polymerizations (so far accessible only on very coarse-grained level) can be microscopically described. Equilibration is verified comparing conformations and melt structure with smaller scale conventional simulations.

5D Entanglement in Star Polymer Dynamics

“…We have represented their data of the branch point diffusion with red dots in Figure . Because of widespread universality in polymer physics, an apples‐to‐apples comparison is possible between the two models, provided we rescale the units of measurement. Our reference point is the first peak of the curve, signaling the departure from reptation (linear chain dynamics), to structurally slower inter‐star dynamics.…”

Computational compound screening of biomolecules and soft materials by molecular simulations

“…One famous example is the Kremer-Grest polymer model [128,129]. Zhang et al demonstrated that a melt of this phenomenological model can broadly be backmapped to many different types of homopolymers [130]. Everaers et al recently matched the generic large-scale behavior of Kremer-Grest simulations to chemistry-specific experiments via the Kuhn length [131].…”

Hierarchical modelling of polystyrene melts: from soft blobs to atomistic resolution

“…The soft-sphere model proposed for the PS is motivated by arguments [22,29,30,32] based on general polymer physics. The model aims to capture long-wavelength conformational and structural properties of PS melts, accurately enough for performing backmapping at one state point.…”

“…Melts with the sameN form a single class of materials which can be described [29] (in renormalized space) by a single blob-based model. This common model can be used to inter-convert [29] chemically different materials within the sameN -class. Increasing N b has two important consequences: a) the conformations of subchains approach the Gaussian statistics of ideal random-walks and b) the correlation hole of blobs becomes more shallow, i.e.…”

“…For both cases the small parameter controlling convergence is 1/ N b . Therefore, for large N b the interactions in blob-based models can be approximated by generic expressions [29][30][31][32] inspired by the ideal random-walk limit. Deviations from the asymptotic Gaussian behavior are taken implicitly into account by "renormalizing" the parameters in the generic expressions.…”