Semidilute Polymer Solutions at Equilibrium and under Shear Flow

Abstract

The properties of semidilute polymer solutions are investigated at equilibrium and under shear flow by mesoscale simulations, which combine molecular dynamics simulations and the multiparticle collision dynamics approach. In semidilute solution, intermolecular hydrodynamic and excluded volume interactions become increasingly important due to the presence of polymer overlap. At equilibrium, the dependence of the radius of gyration, the structure factor, and the zero-shear viscosity on the polymer concentration is determined and found to be in good agreement with scaling predictions. In shear flow, the polymer alignment and deformation are calculated as a function of concentration. Shear thinning, which is related to flow alignment and finite polymer extensibility, is characterized by the shear viscosity and the normal stress coefficients

Hydrodynamic correlations in multiparticle collision dynamics fluids

“…Similar nonequilibrium properties have been studied for colloids [7,[20][21][22][23][24][25][26], polymers [19,[27][28][29][30][31][32][33][34], vesicles [35], and cells [36,37] in flow fields, colloids in viscoelastic fluids [38], as well as for self-propelled spheres [39][40][41], rods [3,42], and other swimming objects [43][44][45]. Moreover, extensions have been proposed for fluids with nonideal equations of state [46] and mixtures [47].…”

“…The MPC approach has successfully been applied to a broad range of soft matter systems, such as colloids [1,3,4,[8][9][10][11][12][13][14][15] and polymers [3,4,[16][17][18][19] under equilibrium conditions. Similar nonequilibrium properties have been studied for colloids [7,[20][21][22][23][24][25][26], polymers [19,[27][28][29][30][31][32][33][34], vesicles [35], and cells [36,37] in flow fields, colloids in viscoelastic fluids [38], as well as for self-propelled spheres [39][40][41], rods [3,42], and other swimming objects [43][44][45].…”

“…The simulation of such systems is often rather demanding in terms of computational resources since it can involve as much as 10 4 -10 6 embedded particles and 10 6 -10 9 MPC particles. Hence, such systems can only be studied on massively parallel platforms [19,48].…”

Lateral migration of flexible fibers in Poiseuille flow between two parallel planar solid walls

“…Dynamics of flexible fibers in simple shear and Poiseuille flows has been analyzed theoretically, numerically and experimentally in numerous publications [1][2][3][4][5][6][7][8][9][10][11][12]. Migration of fibers or vesicles in Poiseuille flow [13][14][15][16][17][18][19] is the fundamental problem of modern lab-on-chip hydrodynamics, important in various biological, medical and industrial contexts, such as Brownian dynamics of proteins, actins, DNA or biological polymers, cell motion, swimming of microorganisms, drug delivery, transport of microparticles [20][21][22].…”

Dynamics of fibers in a wide microchannel

“…Altering these parameters, the property of the fiber model can be changed from fully rigid to flexible. It is used widely to model flexible fibers in various simulation techniques ranging from Monte Carlo simulations [24] to Brownian [25,26] and molecular dynamics [27].…”