Simulations of distribution functions for rod-like macromolecules in linear flow near solid surfaces

A. Hijazi, A. Khater

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Brownian two-dimensional simulations are constructed to calculate the probability distribution functions (PDFs), for macromolecular rod-like particles in a flowing solution near solid surfaces. This is done for a wide range of α = γ̇/Drot, where γ̇ is the constant shear rate of the linear hydrodynamic flow and Drot is the diffusion coefficient for the molecular Brownian rotational motion. The surface simulations are developed on the basis of bulk simulations that are in agreement with the exact numerical solutions of the bulk Boeder differential equation (BDE). This procedure ensures an appropriate limit for the surface simulations. Surface restitution is introduced for Brownian and hydrodynamic events to develop an algorithm for the surface collisions of the macromolecules. The surface PDFs, given as a function of spatial and angular co-ordinates, are calculated for the possible range of restitution coefficients that model interactions between molecular species and surface topographies. These PDFs are consistently concave in the depletion layer as is physically expected. For small α or low flow conditions, the surface spatial PDF are shown to be the result of a dynamic balance between competing Brownian and hydrodynamic collisions restitution. For large α, the rod-like macromolecules are shown to be evacuated from the depletion layer by the dominant hydrodynamic collisions restitution. This is consistent with experimental observations. The surface angular PDF for the depletion layer are also calculated, showing marked differences from their bulk counterpart.

Original languageEnglish
Pages (from-to)213-227
Number of pages15
JournalComputational Materials Science
Volume20
Issue number2
DOIs
Publication statusPublished - 2001
Externally publishedYes

Fingerprint

Macromolecules
macromolecules
solid surfaces
Distribution functions
Distribution Function
rods
distribution functions
probability distribution functions
Probability Distribution Function
Probability distributions
Hydrodynamics
Simulation
Depletion
simulation
hydrodynamics
depletion
Collision
collisions
Coefficient of restitution
Surface Topography

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Simulations of distribution functions for rod-like macromolecules in linear flow near solid surfaces. / Hijazi, A.; Khater, A.

In: Computational Materials Science, Vol. 20, No. 2, 2001, p. 213-227.

Research output: Contribution to journalArticle

@article{b46c109ddf0c47fa951004cb45095321,
title = "Simulations of distribution functions for rod-like macromolecules in linear flow near solid surfaces",
abstract = "Brownian two-dimensional simulations are constructed to calculate the probability distribution functions (PDFs), for macromolecular rod-like particles in a flowing solution near solid surfaces. This is done for a wide range of α = γ̇/Drot, where γ̇ is the constant shear rate of the linear hydrodynamic flow and Drot is the diffusion coefficient for the molecular Brownian rotational motion. The surface simulations are developed on the basis of bulk simulations that are in agreement with the exact numerical solutions of the bulk Boeder differential equation (BDE). This procedure ensures an appropriate limit for the surface simulations. Surface restitution is introduced for Brownian and hydrodynamic events to develop an algorithm for the surface collisions of the macromolecules. The surface PDFs, given as a function of spatial and angular co-ordinates, are calculated for the possible range of restitution coefficients that model interactions between molecular species and surface topographies. These PDFs are consistently concave in the depletion layer as is physically expected. For small α or low flow conditions, the surface spatial PDF are shown to be the result of a dynamic balance between competing Brownian and hydrodynamic collisions restitution. For large α, the rod-like macromolecules are shown to be evacuated from the depletion layer by the dominant hydrodynamic collisions restitution. This is consistent with experimental observations. The surface angular PDF for the depletion layer are also calculated, showing marked differences from their bulk counterpart.",
author = "A. Hijazi and A. Khater",
year = "2001",
doi = "10.1016/S0927-0256(00)00178-6",
language = "English",
volume = "20",
pages = "213--227",
journal = "Computational Materials Science",
issn = "0927-0256",
publisher = "Elsevier",
number = "2",

}

TY - JOUR

T1 - Simulations of distribution functions for rod-like macromolecules in linear flow near solid surfaces

AU - Hijazi, A.

AU - Khater, A.

PY - 2001

Y1 - 2001

N2 - Brownian two-dimensional simulations are constructed to calculate the probability distribution functions (PDFs), for macromolecular rod-like particles in a flowing solution near solid surfaces. This is done for a wide range of α = γ̇/Drot, where γ̇ is the constant shear rate of the linear hydrodynamic flow and Drot is the diffusion coefficient for the molecular Brownian rotational motion. The surface simulations are developed on the basis of bulk simulations that are in agreement with the exact numerical solutions of the bulk Boeder differential equation (BDE). This procedure ensures an appropriate limit for the surface simulations. Surface restitution is introduced for Brownian and hydrodynamic events to develop an algorithm for the surface collisions of the macromolecules. The surface PDFs, given as a function of spatial and angular co-ordinates, are calculated for the possible range of restitution coefficients that model interactions between molecular species and surface topographies. These PDFs are consistently concave in the depletion layer as is physically expected. For small α or low flow conditions, the surface spatial PDF are shown to be the result of a dynamic balance between competing Brownian and hydrodynamic collisions restitution. For large α, the rod-like macromolecules are shown to be evacuated from the depletion layer by the dominant hydrodynamic collisions restitution. This is consistent with experimental observations. The surface angular PDF for the depletion layer are also calculated, showing marked differences from their bulk counterpart.

AB - Brownian two-dimensional simulations are constructed to calculate the probability distribution functions (PDFs), for macromolecular rod-like particles in a flowing solution near solid surfaces. This is done for a wide range of α = γ̇/Drot, where γ̇ is the constant shear rate of the linear hydrodynamic flow and Drot is the diffusion coefficient for the molecular Brownian rotational motion. The surface simulations are developed on the basis of bulk simulations that are in agreement with the exact numerical solutions of the bulk Boeder differential equation (BDE). This procedure ensures an appropriate limit for the surface simulations. Surface restitution is introduced for Brownian and hydrodynamic events to develop an algorithm for the surface collisions of the macromolecules. The surface PDFs, given as a function of spatial and angular co-ordinates, are calculated for the possible range of restitution coefficients that model interactions between molecular species and surface topographies. These PDFs are consistently concave in the depletion layer as is physically expected. For small α or low flow conditions, the surface spatial PDF are shown to be the result of a dynamic balance between competing Brownian and hydrodynamic collisions restitution. For large α, the rod-like macromolecules are shown to be evacuated from the depletion layer by the dominant hydrodynamic collisions restitution. This is consistent with experimental observations. The surface angular PDF for the depletion layer are also calculated, showing marked differences from their bulk counterpart.

UR - http://www.scopus.com/inward/record.url?scp=0034916542&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034916542&partnerID=8YFLogxK

U2 - 10.1016/S0927-0256(00)00178-6

DO - 10.1016/S0927-0256(00)00178-6

M3 - Article

VL - 20

SP - 213

EP - 227

JO - Computational Materials Science

JF - Computational Materials Science

SN - 0927-0256

IS - 2

ER -