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Title: Dissipative particle dynamics simulation of dilute polymer solutions—Inertial effects and hydrodynamic interactions

We examine the accuracy of dissipative particle dynamics (DPD) simulations of polymers in dilute solutions with hydrodynamic interaction (HI), at the theta point, modeled by setting the DPD conservative interaction between beads to zero. We compare the first normal-mode relaxation time extracted from the DPD simulations with theoretical predictions from a normal-mode analysis for theta chains. We characterize the influence of bead inertia within the coil by a ratio L{sub m}/R{sub g}, where L{sub m} is the ballistic distance over which bead inertia is lost, and R{sub g} is the radius of gyration of the polymer coil, while the HI strength per bead h* is determined by the ratio of bead hydrodynamic radius (r{sub H}) to the equilibrium spring length. We show how to adjust h* through the spring length and monomer mass, and how to optimize the accuracy of DPD for fixed h* by increasing the friction coefficient (γ ≥ 9) and by incorporating a nonlinear distance dependence into the frictional interaction. Even with this optimization, DPD simulations exhibit deviations of over 20% from the theoretical normal-mode predictions for high HI strength with h* ≥ 0.20, for chains with as many as 100 beads, which is a larger deviation than is found formore » Stochastic rotation dynamics simulations for similar chains lengths and values of h*.« less
Authors:
;  [1] ;  [2] ;  [3]
  1. Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)
  2. Department of Physics, University of Michigan, Ann Arbor, Michigan (United States)
  3. Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan (United States)
Publication Date:
OSTI Identifier:
22360153
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Rheology; Journal Volume: 58; Journal Issue: 4; Other Information: (c) 2014 The Society of Rheology; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ACCURACY; COMPARATIVE EVALUATIONS; DISTANCE; FRICTION FACTOR; LENGTH; MATHEMATICAL SOLUTIONS; NORMAL-MODE ANALYSIS; POLYMERS; RELAXATION TIME; SIMULATION