Multi-particle collision dynamics for a coarse-grained model of soft colloids applied to ring polymers

Abstract

The simulation of polymer solutions often requires the development of methods that accurately include hydrodynamic interactions. Resolution on the atomistic scale is too computationally expensive to cover mesoscopic time and length scales on which the interesting polymer phenomena are observed. Therefore, coarse-graining methods have to be applied. In this work, the solvent is simulated using the well-established multi-particle collision dynamics scheme, and for the polymer, different coarse-graining methods are employed and compared against the monomer resolved Kremer–Grest model by their resulting diffusion coefficients. This research builds on previous work [Ruiz-Franco et al., J. Chem. Phys. 151, 074902 (2019)], in which star polymers and linear chains in a solvent were simulated and two different coarse-graining methods were developed, in order to increase computational efficiency. The present work extends this approach to ring polymers and seeks to refine one of the authors’ proposed model: the penetrable soft colloid model. It was found that both proposed models are not well suited to ring polymers; however, the introduction of a factor to the PSC model delivers satisfying results for the diffusion behavior by regulating the interaction intensity with the solvent.

Diffusiophoretic Brownian Dynamics: Characterization of Hydrodynamic Effects for an Active Chemoattractive Polymer

“…Polymeric systems, where chemical activity regulates structure and dynamics, are of particular interest. Biopolymers like DNA, chromatin, or actin have a functionality provided by the chemical activity of motors/enzymes associated with them. , In chromatin, the correlated motion of active units on chromosomes gives rise to spontaneous segregation and domain formation. , Motivated by these systems, there is a recent increasing interest in the design of synthetic active polymers and on the understanding of their behavior both theoretically − and experimentally. − These filaments have shown to exhibit very diverse phenomena like swelling, ,− coil-to-globule transition, − or spiral formation. , For the specific case of phoretically induced activity, a chain of chemically active colloids has demonstrated similar coil-to-globule transition with a decreasing Flory exponent with activity in a limited range of activities and sizes …”