Confinement and complex viscosity
Autor: | Alan Jeffrey Giacomin, Rossana Pasquino, S. J. Coombs |
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Přispěvatelé: | Coombs, S. J., Giacomin, A. J., Pasquino, R. |
Rok vydání: | 2021 |
Předmět: |
Fluid Flow and Transfer Processes
chemistry.chemical_classification Physics Persistence length Rheometry Velocity gradient Mechanical Engineering Computational Mechanics Polymer Condensed Matter Physics 01 natural sciences 010305 fluids & plasmas Physics::Fluid Dynamics Condensed Matter::Soft Condensed Matter chemistry.chemical_compound chemistry Mechanics of Materials Chemical physics 0103 physical sciences Polystyrene Dumbbell 010306 general physics Shear flow Suspension (vehicle) |
Zdroj: | Physics of Fluids. 33:053104 |
ISSN: | 1089-7666 1070-6631 |
Popis: | Whereas much is known about the complex viscosity of polymeric liquids, far less is understood about the behavior of this material function when macromolecules are confined. By confined, we mean that the gap along the velocity gradient is small enough to reorient the polymers. We examine classical analytical solutions [O. O. Park and G. G. Fuller, “Dynamics of rigid and flexible polymer chains in confined geometries. II. Time-dependent shear flow,” J. Non-Newtonian Fluid Mech. 18, 111–122 (1985)] for a confined rigid dumbbell suspension in small-amplitude oscillatory shear flow. We test these analytical solutions against the measured effects of confinement on both parts of the complex viscosity of a carbopol suspension and three polystyrene solutions. From these comparisons, we find that both parts of the complex viscosity decrease with confinement and that macromolecular orientation explains this. We find the persistence length of macromolecular confinement, L p, to be independent of both λ ω and λ γ 0. |
Databáze: | OpenAIRE |
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