Reduction of the effective shear viscosity in polymer solutions due to crossflow migration in microchannels: Effective viscosity models based on DPD simulations

Palmer, Teresa Lynne; Baardsen, G.; Skartlien, R.

doi:10.1080/01932691.2017.1306784

Cited by 9 publications

(18 citation statements)

References 50 publications

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“…The current study delas only with Poseuille shear flow. It is essential to have high Schmidt numbers (Sc ≫ 1) to achieve realistic polymer migration effects [22,23,24], and the DPD parameters were adjusted to achieve Sc = 600 as described earlier [10]. The viscous hydrodynamic coupling to the confining walls is automatically accounted for via the molecular forces.…”

Section: Dpd Setup With Adsorptionmentioning

confidence: 99%

“…The adsorption isotherm (by physisorption) and polymer solubility (in the solvent fluid) can be controlled by the strengths of the molecular interaction potentials that are input to the model. A 3D DPD simulator for parallel processing was tailored to oil/water/polymer flow in microchannels with arbitrary wall geometries [10]. Our code was parallelized using a domain-decomposition method with a parallel linked cell-list approach, which was first introduced for MD simulations [25] and later generalized to DPD [26].…”

Section: Dpd Setup With Adsorptionmentioning

confidence: 99%

“…The simulation data were then used in conjunction with a modified Ma-Graham model for the wall-to-wall polymer concentration profile, to construct a first-order phenomenological model for the depletion layer thickness as function of Weissenberg number or normalized shear rate. This can further be used in effective viscosity models of the type we developed earlier [10].…”

Section: Introductionmentioning

confidence: 98%

“…The associated drift-flux is balanced by a diffusion flux back towards the walls [2,9] and the equilibrium state has lowered polymer concentration close to the walls, and higher concentration in the core of the channel. A combined algebraic effective viscosity and depletion layer model was developed by us [10] for the case of no adsorption. This phenomenological model was based on DPD (Dissipative Particle Dynamics) simulations of polymer chains in water, and the hydrodynamic theory of Ma and Graham for dumbbells [2].…”

Section: Introductionmentioning

confidence: 99%

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Effects of polymer adsorption on the effective viscosity in microchannel flows: phenomenological slip layer model from molecular simulations

Palmer

Espås

Skartlien

2018

Journal of Dispersion Science and Technology

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Molecular simulations (Dissipative Particle Dynamics -DPD) were used to quantify the effect of polymer adsorption on the effective shear viscosity of a semi-dilute polymer solution in microchannel Poseuille flow. It is well known that polymer depletion layers develop adjacent to solid walls due to hydrodynamic forces, causing an apparent wall slip and reduced effective viscosity (increased total flow rate). We found that depletion layers also developed in the presence of hydrodynamically rough adsorbed layers on the wall. Polymer-polymer (steric) repulsion between flowing and adsorbed polymer expanded the depletion layer compared to no-adsorption cases, and the effective viscosity was reduced further. Desorption occurred for higher shear rates, reducing the repulsion effect and shrinking the depletion layers. A phenomenological algebraic model for the depletion layer thickness, including a shear modified adsorption isotherm, was developed based on the simulation data. The depletion layer model can be used together with the effective viscosity model we developed earlier.

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Section: Dpd Setup With Adsorptionmentioning

confidence: 99%

Section: Dpd Setup With Adsorptionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of polymer adsorption on the effective viscosity in microchannel flows: phenomenological slip layer model from molecular simulations

Palmer

Espås

Skartlien

2018

Journal of Dispersion Science and Technology

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“…The understanding of the flow behavior of polymer solutions in confined geometries is of great importance to a variety of applications, such as polymer processing, polymer materials separation, adsorption, lubrication, and enhanced oil recovery, and so forth. In recent years, single biomolecule (e.g., DNA) manipulation and analysis based on microfluidic devices also have fueled the interest in the dynamics of polymer solutions in microchannels .…”

Section: Introductionmentioning

confidence: 99%

Effect of solvent quality on Poiseuille flow of polymer solutions in microchannels: A dissipative particle dynamics study

Lou

et al. 2018

J of Applied Polymer Sci

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The Poiseuille flows of polymer solutions for varying quality solvents in microchannels have been simulated using dissipative particle dynamics. In particular, the velocity distributions and the polymer migration across the channel have been investigated for good, athermal, and poor solvents. The velocity profiles for all three kinds of solvent deviate from the parabolic profile, and the velocity profile of the athermal solvent falls in between the good solvent and the poor solvent. For the athermal solvent, a migration away from the wall due to the hydrodynamic interactions between the chains and the wall is observed, and a migration away from the channel center due to the different chain Brownian diffusivities is also observed. For the good solvent, because of the more stretched polymer chains, the migration away from the wall is stronger than that for the athermal solvent. However, the migration away from the channel center is not observed for good solvents. For the poor solvent, the hydrodynamic interaction within the chains is screened, and the polymer chains migrate toward the wall and appear to be absorbed by the wall.

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Coarse‐grained molecular dynamics simulation of polymers: Structures and dynamics

Shi

Huang

2023

WIREs Comput Mol Sci

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For the simulations of polymeric systems, coarse‐grained (CG) molecular dynamics simulations are computationally demanding not only because of their high computational efficiency, but also these CG models can provide sufficient structural and dynamical properties at both micro‐ and meso‐scopic levels. During the past decades, developments of these CG models are roughly in two directions, that is, generic and chemically system‐specific models. The developme of the formmer focuses on the capability of the model to capature the general properties of the system, for instance, scaling relations between both structural and dynamic properties with respect to chain length. On the other hand, to bridging the gap between physics and chemistry, chemically‐specifi models are also widely developed which are able to retain the inherent chemical–physical properties for a given polymer system. However, due to the reduction of atomistic degree of freedom a faithful reproduction of structure and especialy dynamics properties of the system is the maijor challenge. In this review, after a brief introduction of some widely used generic models, we present an overview of both recent achievements and remainning challendges in the development of chemically‐specific CG approaches, for the simulations of polymer systems.This article is categorized under: Structure and Mechanism > Computational Materials Science Molecular and Statistical Mechanics > Molecular Dynamics and Monte‐Carlo Methods

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Reduction of the effective shear viscosity in polymer solutions due to crossflow migration in microchannels: Effective viscosity models based on DPD simulations

Abstract: the polymer persistence length and corresponding potential/thermal energy ratio.

Cited by 9 publications

References 50 publications

Effects of polymer adsorption on the effective viscosity in microchannel flows: phenomenological slip layer model from molecular simulations

Effects of polymer adsorption on the effective viscosity in microchannel flows: phenomenological slip layer model from molecular simulations

Effect of solvent quality on Poiseuille flow of polymer solutions in microchannels: A dissipative particle dynamics study

Coarse‐grained molecular dynamics simulation of polymers: Structures and dynamics

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