, Volume 2, Issue 1, pp 73–81 | Cite as

Structure of polyelectrolyte brushes studied by coarse grain simulations

  • Hitoshi Washizu
  • Tomoyuki Kinjo
  • Hiroaki Yoshida
Open Access
Research Article


As an example of a very low friction system, Monte Carlo Brownian dynamics simulations have been used to calculate equilibrium structures of a polyelectrolyte brush grafted onto planes. The polymers were calculated in a semi-flexible coarse-grain model that is appropriate to treat the charge density of the polyion. The effect of linear charge density on the polyion ξ, the surface negative charge, and added salts were studied. In salt-free solution, scaling theories predicted the structure well in the low — region. In the high ξ region, additional shrinkage was found from the theories due to counterion condensation. The effect of surface charge showed not only the repulsion of the polyion from the surface but also the shrinkage in the high ξ region due to the additional counterions required for electrical neutrality. The addition of salts led to the shrinkage of the brush heights, and in the high ξ region, additional extension was found. The computational strategy for calculating the friction dynamics of the system is also discussed.


polyelectrolyte brush friction Monte Carlo Brownian dynamics simulation soft materials automotive tribology 


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© The author(s) 2014

This article is published under license to BioMed Central Ltd. Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited

Authors and Affiliations

  • Hitoshi Washizu
    • 1
    • 2
  • Tomoyuki Kinjo
    • 1
    • 2
  • Hiroaki Yoshida
    • 1
    • 2
  1. 1.Toyota Central R&D Labs., Inc.AichiJapan
  2. 2.Elements Strategy Initiative for Catalysts and BatteriesKyoto UniversityKatsura, KyotoJapan

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