Dilute polymer solutions under shear flow: Comprehensive qualitative analysis using a bead-spring chain model with a FENE-Fraenkel spring

被引:3
|
作者
Pincus, I. [1 ]
Rodger, A. [2 ]
Prakash, J. Ravi [1 ]
机构
[1] Monash Univ, Dept Chem Engn, Melbourne, Vic 3800, Australia
[2] Macquarie Univ, Sch Nat Sci, Macquarie Pk, NSW 2109, Australia
关键词
broken vertical bar; BROWNIAN DYNAMICS SIMULATIONS; EXCLUDED-VOLUME INTERACTIONS; PARAMETER-FREE PREDICTION; NON-NEWTONIAN VISCOSITY; HYDRODYNAMIC INTERACTION; ROUSE CHAINS; GAUSSIAN APPROXIMATION; RHEOLOGICAL PROPERTIES; SEMIFLEXIBLE POLYMERS; STATISTICAL-MECHANICS;
D O I
10.1122/8.0000517
中图分类号
O3 [力学];
学科分类号
08 ; 0801 ;
摘要
Although the nonequilibrium behavior of polymer solutions is generally well understood, particularly in extensional flow, there remain several unanswered questions for dilute solutions in simple shear flow, and full quantitative agreement with experiments has not been achieved. For example, experimental viscosity data exhibit qualitative differences in shear-thinning exponents, the shear rate for the onset of shear-thinning, and high-shear Newtonian plateaus depending on polymer semiflexibility, contour length, and solvent quality. While polymer models are able to incorporate all of these effects through various spring force laws, bending potentials, excluded volume (EV) potentials, and hydrodynamic interaction (HI), the inclusion of each piece of physics has not been systematically matched to experimentally observed behavior. Furthermore, attempts to develop multiscale models (in the sense of representing an arbitrarily small or large polymer chain) which can make quantitative predictions are hindered by the lack of ability to fully match the results of bead-rod models, often used to represent a polymer chain at the Kuhn-step level, with bead-spring models, which take into account the entropic elasticity. In light of these difficulties, this work aims to develop a general model based on the so-called FENE-Fraenkel spring, originally formulated by Larson and co-workers [J. Chem. Phys. 124 (2006)], which can span the range from rigid rod to traditional entropic spring, as well as include a bending potential, EV, and HI. As we show, this model can reproduce, and smoothly move between, a wide range of previously observed polymer solution rheology in shear flow.
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页码:373 / 402
页数:30
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