3 edition of Hydrodynamics of dilute rouse polymer solutions under flow found in the catalog.
Hydrodynamics of dilute rouse polymer solutions under flow
Written in English
|Statement||by Shi-qing Wang.|
|LC Classifications||Microfilm 89/118 (Q)|
|The Physical Object|
|LC Control Number||88894041|
hydrodynamic interaction in polymer solutions. Our analyses reveal that equilibrium polymer dynamics in dilute solution, under a typical DPD simulation conditions, obey the Zimm model very well. With a further reduction in the Schmidt number, a deviation from the Zimm model to the Rouse model is . "Nonlinear flow behavior of entangled polymer solutions: yield like entanglement-disentanglement transition", P. Tapadia and S. Q. Wang, Macromolecu (). "Experimental studies of extrudate swell behavior of linear polybutadiene melts", Z. Zhu and S. Q. Wang, J. Rheol. 48, ().
In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and has several subdisciplines, including aerodynamics (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion). Fluid dynamics has a wide range of applications, including calculating forces and moments on aircraft. Polymer chain dynamics in dilute solution under Couette flow: Behavior of poly(α-methylstyrene) in good solvent J. Chem. Phys. , (); / Diffusion Equation versus Coupled Langevin Equations Approach to Hydrodynamics of Dilute Polymer Solutions.
Second, it has been reported many times, in experimental works [5–9] as well as in numerical simulations [10, 11, 5, 12–15, 6, 16, 7, 17, 18], that the Rouse model fails when considering the diffusion of the center of mass (COM) of a tagged polymer in a melt (if entanglements are efficient in the systems, the Rouse model is, however. T he flow of polymers, either as melts or in solution, shows some intriguing features. Polymeric liquids climb stirrer rods (the Weissenberg effect), swell up at the exit of an extruder or capillary, and can even sustain tubeless siphons (, ). These phenomena cannot be explained by classical hydrodynamics. Yet they are typical of most polymeric substances, independent of their.
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Using Langevin method the hydrodynamics of dilute polymer solutions under flow is described by deriving an effective hydrodynamic equation for these solutions. The systematics of the present treatment is demonstrated by considering Rouse chains as a simple by: 3.
The conformational characteristics of polymer coils in dilute solution under shear flow were investigated by means of wide angle laser light scattering in an apparatus similar to one used by Cottrell, Merrill, and Smith (J.
Polym. Sci., Polym. Phys.7, ).1 The polymer solution was subjected to steady, homogeneous shear flow in the annulus between concentric cylinders by rotation Cited by: Request PDF | Macroscopic Hydrodynamics of Dilute Polymer Solutions | Starting from coupled stochastic differential equations which describe the microscopic dynamics of the polymer-solvent system.
The problem of the motions of a chain molecule diffusing in a viscous fluid under the influence of external forces or currents is considered for a particular model.
This model is a chain of beads connected by ideal springs. Hydrodynamic interaction between the beads is introduced in the approximate form due to Kirkwood and by: The contribution discusses two central models for polymer dynamics, the Rouse model and the Zimm model. The latter takes into account hydrodynamic interactions, and is hence appropriate for dilute Author: Burkhard Dünweg.
Dilute polymer solutions are characterized by several rheological parameters, among which the viscosity and the relaxation time assume great importance [21 Macosko, C., Rheology: Principles, Measurements, and Applications (Wiley-VCH, New York, ).The viscosity is a measure of the drag exerted by the fluid as a response to an external flow field, and is relatively easy to measure.
Abstract. The contribution discusses two central models for polymer dynamics, the Rouse model and the Zimm model. The latter takes into account hydrodynamic interactions, and is hence appropriate for dilute solutions. Hydrodynamics of dilute rouse polymer solutions under flow.
Physics Letters A(4), DOI: /(87) The behaviour of dilute polymer solutions in sink flow, viz., radial flow toward a point, was investigated experimentally and theoretically. Solutions of polyethylene oxide, in the drag-reducing concentration range, were pushed through a 60° conical channel at Reynolds numbers of order 10 inary studies revealed a range of flow conditions in which the flow was free of secondary motion.
Recent progress toward understanding the rheology of dilute solutions of flexible polymers is reviewed, emphasizing experimental results from flows imaging single deoxyribonucleic acid (DNA) molecules and filament-stretching rheometry of dilute polystyrene Boger fluids, as well as Brownian dynamics (BD) simulations of these flows.
The bead-spring and bead-rod models are. Dynamic viscoelastic behavior was investigated for solutions of polystyrene in tricresyl phosphate, a good solvent, at concentrations, c, less than the coil‐overlapping concentration, c *.At the infinite dilution limit, the behavior was in accord with the theory of Doi and Edwards involving the excluded volume potential and hydrodynamic interaction (HDI).
The necessary coordination of the motions of different parts of a polymer molecule is made the basis of a theory of the linear viscoelastic properties of dilute solutions of coiling polymers.
This is accomplished by use of the concept of the submolecule, a portion of polymer chain long enough for the separation of its ends to approximate a.
Using many-body dissipative particle dynamics (MDPD), polymer solutions with concentrations spanning dilute and semidilute regimes are modeled. The parameterization of MDPD interactions for systems with liquid–vapor coexistence is established by mapping to the mean-field Flory–Huggins theory.
The characterization of static and dynamic properties of polymer chains is focused on the effects. Flexible Polymer Chain Dynamics in Elongational Flow fulfills a need by presenting the most important advances in the field of flexible polymer chains in "strong" flow in a single literature source.
Although several excellent treatises on polymer dynamics have appeared over the years, most of them deal with polymer chains in the quiescent state.
In an earlier work (Litvinov et al., E 77, ()), a model for a polymer molecule in solution based on the smoothed dissipative particle dynamics method (SDPD) has been presented.
In the present paper, we show that the model can be extended to three-dimensional situations and simulate effectively diluted and concentrated polymer solutions.
For an isolated suspended polymer. The viscosity-radius relationship for concentrated polymer solutions Dave E. Dunstan Department of Chemical Engineering, University of Melbourne, VICAustralia.
[email protected] A key assumption of polymer physics is that the random chains polymers extend in flow. A key assumption used in the models of polymer dynamics and rheology is that the chains extend in the flow to reduce the viscosity and imbue the solution with elasticity Here we. The behavior of polymer solutions in simple shear flows has been the subject of considerable research in the past.
On the other hand, reports on polymers in elongational flow have appeared comparatively recently in the literature. Elongational flow with an inherent low vorticity is known to be more. Theories of DNA electrophoretic separations generally treat the DNA as a free draining polymer moving in an electric field at a rate that depends on the effective charge density of the molecule.
Separations can occur in sieving media ranging from ultradilute polymer solutions to tightly cross-linked gels. It has recently been shown that DNA is not free-draining when both electric and.
Experimental results for dilute high-weight polymer solutions have shown that D T is independent of polymer length [24, 5]. Recent experiments [25–27] have, however, shown that D T becomes polymer length dependent in the limit of short polymers. With a hydrodynamic argument we evaluate the scaling properties of the thermophoretic force where.
The Rouse model is the simplest description of dilute polymer solutions that captures some aspects of their flow behaviour. Polymer molecules are represented in the model by linear chains of identical spherical beads connected by ‘Hookean’ springs, and the solvent is modelled as a Newtonian fluid, characterised by its viscosity.where R is the position of bead n at time t, k B is Boltzmann's constant, T the temperature, b the Rouse segment length, ζ the friction factor of the bead, and g is a noise term that accounts for Brownian motion.
From the solution to Eq. 1, the motion of a polymer, ranging from the diffusion of the whole molecule to rearrangements of single segments, can be described.The module is an implementation of the Rouse and Zimm models in which polymers are represented as chains of beads connected by elastic segments.
The dynamics of the polymer in dilute solution is modeled by the Brownian motion of the beads. The Rouse model ignores the excluded volume and hydrodynamics interactions.