## Abstract

Lattice Monte Carlo simulations are widely used to study the effect of walls on the concentration profile in polymer solutions. The scaling theory predicts that the monomer density at a distance x from the wall, reduced by the bulk density, is proportional to (x/R_{g0})^{1/v} at low concentrations, and the correlation length replaces R_{g0} in the semidilute solution, where R_{g0} is the radius of gyration and v is the Flow exponent for the chain dimension. We conducted simulations for long chains on a cubic lattice to find that a positive penetration depth γ is needed to see an agreement with the theory. The monomers perceive a theoretical wall at an off-lattice position of γ behind the presumed wall on the lattice points. We found γ ∼ 0.13 of the lattice unit at low concentrations but ∼0.36 in the semidilute solution for athermal chains. For Θ solutions, γ was 0.31-0.36 at all concentrations. We ascribe the positive γ to uneven chain segment propagation in the chain update in a nonuniform density profile.

Original language | English (US) |
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Pages (from-to) | 7121-7126 |

Number of pages | 6 |

Journal | Macromolecules |

Volume | 34 |

Issue number | 20 |

DOIs | |

State | Published - Sep 25 2001 |

## ASJC Scopus subject areas

- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry