ORCID Profile
0000-0002-1702-6392
Current Organisations
Indian Institute of Science
,
Monash University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Chemical Engineering | Rheology | Chemical Engineering Not Elsewhere Classified | Nanotechnology | Soft Condensed Matter | Nanotechnology | Physiology | Electrochemistry | Nanomaterials | Computational Fluid Dynamics | Biosensor Technologies | Fluidisation and Fluid Mechanics | Animal Physiology—Systems | Biomedical Engineering Not Elsewhere Classified | Interdisciplinary Engineering | Composite and Hybrid Materials | Thermodynamics and Statistical Physics |
ANZSRC Socio-Economic Objective (SEO)
Higher education | Biological sciences | Other | Expanding Knowledge in the Chemical Sciences | Expanding Knowledge in the Physical Sciences | Other | Cardiovascular system and diseases | Physical sciences | Oil and Gas Extraction | Mineral Resources (excl. Energy Resources) not elsewhere classified | Energy Storage (excl. Hydrogen) | Paints | Expanding Knowledge in Engineering | Public health not elsewhere classified | Other fibre processing and textiles | Organs, diseases and abnormal conditions not elsewhere classified
Related Links
Publications
Viscometric functions for Hookean dumbbells with excluded volume and hydrodynamic interactions
Publisher: Society of Rheology
Date: 09-2002
DOI: 10.1122/1.1501924
Rouse Chains with Excluded Volume Interactions: Linear Viscoelasticity
Publisher: American Chemical Society (ACS)
Date: 11-04-2001
DOI: 10.1021/MA0006880
Viscosity Radius of Polymers in Dilute Solutions: Universal Behavior from DNA Rheology and Brownian Dynamics Simulations
Publisher: American Chemical Society (ACS)
Date: 20-10-2014
DOI: 10.1021/MA500960F
Uniaxial extensional viscosity of semidilute DNA solutions
Publisher: Springer Science and Business Media LLC
Date: 11-2019
The free energy of a deforming Lodge rubber-like liquid
Publisher: Elsevier BV
Date: 11-1991
Brownian dynamics simulation of polymer collapse in a poor solvent: influence of implicit hydrodynamic interactions
Publisher: Royal Society of Chemistry (RSC)
Date: 2008
DOI: 10.1039/B717350D
Report on the International Workshop on Mesoscale and Multiscale Description of Complex Fluids
Publisher: ETH Zurich; Applied Rheology
Date: 2006
Measurement and Prediction of the Elongational Stress Growth in a Dilute Solution of DNA Molecules
Publisher: American Chemical Society (ACS)
Date: 27-10-0012
DOI: 10.1021/MA0511907
Dynamic Crossover Scaling in Polymer Solutions
Publisher: American Physical Society (APS)
Date: 21-08-2012
Rheological Observation of Glassy Dynamics of Dilute Polymer Solutions near the Coil-Stretch Transition in Elongational Flows
Publisher: American Physical Society (APS)
Date: 20-04-2007
A successive fine-graining scheme for predicting the rheological properties of dilute polymer solutions
Publisher: Society of Rheology
Date: 11-2004
DOI: 10.1122/1.1807841
Analysis of radial segregation of granular mixtures in a rotating drum
Publisher: Springer Science and Business Media LLC
Date: 2000
Universal dynamics of dilute and semidilute solutions of flexible linear polymers
Publisher: Elsevier BV
Date: 10-2019
Is the Electrostatic Blob Model Relevant to Dilute Polyelectrolyte Solutions Undergoing Shear Flow?
Publisher: American Chemical Society (ACS)
Date: 19-02-2008
DOI: 10.1021/MA702114U
Parameter-free prediction of DNA dynamics in planar extensional flow of semidilute solutions
Publisher: Society of Rheology
Date: 2017
DOI: 10.1122/1.4972237
Direct observation of DNA dynamics in semidilute solutions in extensional flow
Publisher: Society of Rheology
Date: 2017
DOI: 10.1122/1.4972236
Equilibrium binding energies from fluctuation theorems and force spectroscopy simulations
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6SM02549H
Abstract: Brownian dynamics simulations are used to study the detachment of a particle from a substrate. Although the model is simple and generic, we attempt to map its energy, length and time scales onto a specific experimental system, namely a bead that is weakly bound to a cell and then removed by an optical tweezer. The external driving force arises from the combined optical tweezer and substrate potentials, and thermal fluctuations are taken into account by a Brownian force. The Jarzynski equality and Crooks fluctuation theorem are applied to obtain the equilibrium free energy difference between the final and initial states. To this end, we s le non-equilibrium work trajectories for various tweezer pulling rates. We argue that this methodology should also be feasible experimentally for the envisioned system. Furthermore, we outline how the measurement of a whole free energy profile would allow the experimentalist to retrieve the unknown substrate potential by means of a suitable deconvolution. The influence of the pulling rate on the accuracy of the results is investigated, and umbrella s ling is used to obtain the equilibrium probability of particle escape for a variety of trap potentials.
Dynamic scaling in dilute polymer solutions: The importance of dynamic correlations
Publisher: IOP Publishing
Date: 07-2006
Steady compressible flow of granular materials through a wedge-shaped hopper: the smooth wall, radical gravity problem
Publisher: Elsevier BV
Date: 1988
Computing 3D Chromatin Configurations from Contact Probability Maps by Inverse Brownian Dynamics
Publisher: Elsevier BV
Date: 05-2020
Viscometric Functions for a Dilute Solution of Polymers in a Good Solvent
Publisher: American Chemical Society (ACS)
Date: 03-1999
DOI: 10.1021/MA981534B
Effect of molecular topology on the transport properties of dendrimers in dilute solution at Θ temperature: A Brownian dynamics study
Publisher: AIP Publishing
Date: 16-01-2008
DOI: 10.1063/1.2823034
Abstract: Structure and transport properties of dendrimers in dilute solution are studied with the aid of Brownian dynamics simulations. To investigate the effect of molecular topology on the properties, linear chain, star, and dendrimer molecules of comparable molecular weights are studied. A bead-spring chain model with finitely extensible springs and fluctuating hydrodynamic interactions is used to represent polymer molecules under Θ conditions. Structural properties as well as the diffusivity and zero-shear-rate intrinsic viscosity of polymers with varied degrees of branching are analyzed. Results for the free-draining case are compared to and found in very good agreement with the Rouse model predictions. Translational diffusivity is evaluated and the difference between the short-time and long-time behavior due to dynamic correlations is observed. Incorporation of hydrodynamic interactions is found to be sufficient to reproduce the maximum in the intrinsic viscosity versus molecular weight observed experimentally for dendrimers. Results of the nonequilibrium Brownian dynamics simulations of dendrimers and linear chain polymers subjected to a planar shear flow in a wide range of strain rates are also reported. The flow-induced molecular deformation of molecules is found to decrease hydrodynamic interactions and lead to the appearance of shear thickening. Further, branching is found to suppress flow-induced molecular alignment and deformation.
6th Pacific Rim Conference on Rheology
Publisher: Springer Science and Business Media LLC
Date: 05-2015
Rouse chains with excluded volume interactions in steady simple shear flow
Publisher: Society of Rheology
Date: 11-2002
DOI: 10.1122/1.1514054
Viscoelastic flow in a two-dimensional collapsible channel
Publisher: Elsevier BV
Date: 10-2010
Multiscale simulation of viscoelastic free surface flows
Publisher: Elsevier BV
Date: 12-2006
Parameter-Free Prediction of DNA Conformations in Elongational Flow by Successive Fine Graining
Publisher: American Chemical Society (ACS)
Date: 15-12-2004
DOI: 10.1021/MA035941L
Effect of Solvent Quality on the Coil−Stretch Transition
Publisher: American Chemical Society (ACS)
Date: 12-2010
DOI: 10.1021/MA1019945
Wet and dry internal friction can be measured with the Jarzynski equality
Publisher: American Physical Society (APS)
Date: 17-03-2020
Effect of configuration-dependent intramolecular hydrodynamic interaction on elastocapillary thinning and breakup of filaments of dilute polymer solutions
Publisher: Society of Rheology
Date: 11-2006
DOI: 10.1122/1.2357592
Abstract: We use a new constitutive model for the polymer stress in a dilute polymer solution to predict elastocapillary thinning and breakup of a thin filament of the solution. The constitutive model accounts for the effects of finite chain extensibility and configuration-dependent intramolecular hydrodynamic interaction, and is used in the simple stress balance equation proposed by Entov and Hinch [Entov, V. M., and E. J. Hinch, J. Non-Newtonian Fluid Mech. 72, 31–53 (1997)] for situations where inertial effects are negligible. In their seminal study, Entov and Hinch showed that during the period where the elastic polymer stresses are dominant, the filament radius decreases exponentially with time. We find that configuration-dependent hydrodynamic interactions cause the time constant in this exponential decay to depend on concentration, as observed in recent experiments. Moreover, the phenomenon of coil-stretch hysteresis permits a large polymer stress even though the transient Weissenberg number during elastocapillary thinning decreases below the critical value of 1∕2 for the coil-to-stretch transition of a dilute polymer solution in an extensional flow. As a consequence, the Weissenberg number does not have a lower bound of 2∕3 as predicted originally by Entov and Hinch using a simpler constitutive model that does not account for configuration-dependent hydrodynamic interactions.
A computational study of the effect of viscoelasticity on slot coating flow of dilute polymer solutions
Publisher: Elsevier BV
Date: 02-2008
Rouse model with fluctuating internal friction
Publisher: Society of Rheology
Date: 13-07-2021
DOI: 10.1122/8.0000255
Abstract: A coarse-grained bead-spring-dashpot chain model with the dashpots representing the presence of internal friction is solved exactly numerically for the case of chains with more than two beads. Using a decoupling procedure to remove the explicit coupling of a bead’s velocity with that of its nearest neighbors, the governing set of stochastic differential equations are solved with Brownian dynamics simulations to obtain material functions in oscillatory and steady simple shear flow. Simulation results for the real and imaginary components of the complex viscosity have been compared with the results of previously derived semi-analytical approximations, and the difference in the predictions is seen to diminish with an increase in the number of beads in the chain. The inclusion of internal friction results in a nonmonotonous variation of the viscosity with shear rate, with the occurrence of continuous shear-thickening following an initial shear-thinning regime. The onset of shear-thickening in the first normal stress coefficient is pushed to lower shear rates with an increase in the internal friction parameter.
An alternative to the bead-rod model: Bead-spring chains with successive fine graining
Publisher: Elsevier BV
Date: 02-2008
Shear viscosity for finitely extensible chains with fluctuating internal friction and hydrodynamic interactions
Publisher: Society of Rheology
Date: 09-11-2022
DOI: 10.1122/8.0000498
Abstract: An exact solution of coarse-grained polymer models with fluctuating internal friction and hydrodynamic interactions has not been proposed so far due to a one-to-all coupling between the connector vector velocities that precludes the formulation of the governing stochastic differential equations. A methodology for the removal of this coupling is presented, and the governing stochastic differential equations, obtained by attaching a kinetic interpretation to the Fokker–Planck equation for the system, are integrated numerically using Brownian dynamics simulations. The proposed computational route eliminates the calculation of the ergence of the diffusion tensor, which appears in models with internal friction, and is about an order of magnitude faster than the recursion-based algorithm for the decoupling of connector-vector velocities previously developed [Kailasham et al., J. Rheol. 65, 903 (2021)] for the solution of freely draining models with internal friction. The effects of the interplay of various combinations of finite extensibility, internal friction, and hydrodynamic interactions on the steady-shear-viscosity are examined. While finite extensibility leads solely to shear-thinning, both internal friction and hydrodynamic interactions result in shear-thinning followed by shear-thickening. The shear-thickening induced by internal friction effects is more pronounced than that due to hydrodynamic interactions.
Coil-stretch transition and the breakdown of computations for viscoelastic fluid flow around a confined cylinder
Publisher: Society of Rheology
Date: 2008
DOI: 10.1122/1.2807444
Influence of Shear Thinning on Viscoelastic Fluid–Structure Interaction in a Two-Dimensional Collapsible Channel
Publisher: American Chemical Society (ACS)
Date: 27-04-2011
DOI: 10.1021/IE200173B
Significance of thermal fluctuations and hydrodynamic interactions in receptor-ligand-mediated adhesive dynamics of a spherical particle in wall-bound shear flow
Publisher: American Physical Society (APS)
Date: 05-02-2015
The kinetic theory of dilute solutions of flexible polymers: Hydrodynamic interaction
Publisher: Elsevier
Date: 1999
Optimization of a Brownian-dynamics algorithm for semidilute polymer solutions
Publisher: American Physical Society (APS)
Date: 11-06-2012
Fluid-structure interaction in deformable microchannels
Publisher: AIP Publishing
Date: 10-2012
DOI: 10.1063/1.4759493
Abstract: A polydimethylsiloxane microfluidic device composed of a single microchannel with a thin flexible layer present over a short length along one side of the channel was fabricated and modelled in order to investigate the complex fluid-structure interaction that arises between a flowing fluid and a deformable wall. Experimental measurements of thin layer deformation and pressure drop are compared with predictions of two- and three-dimensional computational models that numerically solve the coupled set of equations governing both the elasticity of the thin layer and the fluid. It is shown that the two-dimensional model, which assumes the flexible thin layer comprises an infinitely wide elastic beam of finite thickness, reasonably approximates a three-dimensional model, and is in excellent agreement with experimental observations of the thin layer profile when the width of the thin layer is beyond a critical value, roughly twice the length of the thin layer.
Brownian dynamics simulations of planar mixed flows of polymer solutions at finite concentrations
Publisher: Elsevier BV
Date: 2015
International Workshop on Mesoscale and Multiscale Description of Complex Fluids (IWMMCOF’06), Prato, Italy, July 5–8, 2006
Publisher: Elsevier BV
Date: 02-2008
Universal consequences of the presence of excluded volume interactions in dilute polymer solutions undergoing shear flow
Publisher: AIP Publishing
Date: 10-08-2004
DOI: 10.1063/1.1775185
Abstract: The role of solvent quality in determining the universal material properties of dilute polymer solutions undergoing steady simple shear flow is examined. A bead-spring chain representation of the polymer molecule is used, and the influence of solvent molecules on polymer conformations is modelled by a narrow Gaussian excluded volume potential that acts pairwise between the beads of the chain. Brownian dynamics simulations data, acquired for chains of finite length, and extrapolated to the limit of infinite chain length, are shown to be model independent. This feature of the narrow Gaussian potential, which leads to results identical to a δ-function repulsive potential, enables the prediction of both universal crossover scaling functions and asymptotic behavior in the excluded volume limit. Universal viscometric functions, obtained by this procedure, are found to exhibit increased shear thinning with increasing solvent quality. In the excluded volume limit, they are found to obey power law scaling with the characteristic shear rate β, in close agreement with previously obtained renormalization group results. The presence of excluded volume interactions is also shown to lead to a weakening of the alignment of the polymer chain with the flow direction.
Hydrodynamic Fluctuations in Soft-Matter Simulations
Publisher: ETH Zurich; Applied Rheology
Date: 2016
Heterogeneous interactions and polymer entropy decide organization and dynamics of chromatin domains
Publisher: Elsevier BV
Date: 07-2022
Dilute polymer solutions under shear flow: Comprehensive qualitative analysis using a bead-spring chain model with a FENE-Fraenkel spring
Publisher: Society of Rheology
Date: 13-01-2023
DOI: 10.1122/8.0000517
Abstract: 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 ex le, 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.
Viscoelastic fluid flow in a 2D channel bounded above by a deformable finite-thickness elastic wall
Publisher: Elsevier BV
Date: 04-2015
Universality of dilute solutions of ring polymers in the thermal crossover region between θ and athermal solvents
Publisher: Society of Rheology
Date: 23-06-2022
DOI: 10.1122/8.0000443
Abstract: Due to their unique topology of having no chain ends, dilute solutions of ring polymers exhibit behavior distinct from their linear chain counterparts. The universality of their static and dynamic properties, as a function of solvent quality z in the thermal crossover regime between θ and athermal solvents, is studied here using Brownian dynamics simulations. The universal ratio URD of the radius of gyration Rg to the hydrodynamic radius RH is determined, and a comparative study of the swelling ratio αg of the radius of gyration, the swelling ratio αH of the hydrodynamic radius, and the swelling ratio αX of the mean polymer stretch X along the x-axis, for linear and ring polymers, is carried out. The ratio URD for dilute ring polymer solutions is found to converge asymptotically to a constant value as z→∞, which is a major difference from the behavior of solutions of linear chains, where no such asymptotic limit exists. Additionally, the ratio of the mean stretch along the x-axis to the hydrodynamic radius, (X/RH), is found to be independent of z for polymeric rings, unlike in the case for linear polymers. These results indicate a fundamental difference in the scaling of static and dynamic properties of rings and linear chains in the thermal crossover regime.
How important are fluctuations in the treatment of internal friction in polymers?
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1SM00613D
Abstract: The Rouse model with internal friction (RIF) is shown with polymer kinetic theory (PKT) to pre-average internal friction and to neglect fluctuations, significantly affecting the model's prediction of properties at equilibrium and in shear flow.
Universality of the collapse transition of sticky polymers
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9SM01361J
Abstract: The swelling of the radius of gyration of a sticky polymer relative to its value in the θ state is identical to the universal swelling of homopolymers in the thermal crossover regime, in terms of a suitably defined renormalised solvent quality z .
The influence of the range of excluded volume interactions on the linear viscoelastic properties of dilute polymer solutions
Publisher: Elsevier BV
Date: 10-2001
Gaussian approximation for finitely extensible bead-spring chains with hydrodynamic interaction
Publisher: Society of Rheology
Date: 07-2006
DOI: 10.1122/1.2206715
The diffusion tensor for Hookean dumbbells in steady shear flow: Analytical approximation
Publisher: Society of Rheology
Date: 07-1992
DOI: 10.1122/1.550317
Abstract: Thermodynamic treatments of the phenomenon of polymer migration in inhomogeneous flows have so far assumed a flow rate independent coefficient of diffusion. Recent investigations have revealed that polymer diffusivity in simple shear flow is anisotropic and flow rate dependent. These properties arise because the average spatial extent of the macromolecule, from being spherical at equilibrium, becomes ellipsoidal on the imposition of a shear flow.Using this insight into the molecular shape, and assuming that there is only one physically important direction in the problem due to the flow field, we derive an approximate analytical expression for the diffusion tensor. This gives values within 1.2% of exact numerical ones, for a wide range of dimensionless shear rates. Clearly, it is important to refine the earlier thermodynamic theories of polymer migration by incorporating the shear rate dependence of polymer diffusivity. The expression derived in this paper is anticipated to be useful in a wide range of problems, where the assumption of ‘‘local homogeneity’’ is justified.
Fluid-Structure Interactions in Soft-Matter Systems: From the Mesoscale to the Macroscale (Prato, 2012)
Publisher: Applied Rheology; ETH Zurich
Date: 2013
Implicit and explicit solvent models for the simulation of a single polymer chain in solution: Lattice Boltzmann versus Brownian dynamics
Publisher: AIP Publishing
Date: 28-10-2009
DOI: 10.1063/1.3251771
Abstract: We present a comparative study of two computer simulation methods to obtain static and dynamic properties of dilute polymer solutions. The first approach is a recently established hybrid algorithm based on dissipative coupling between molecular dynamics and lattice Boltzmann (LB), while the second is standard Brownian dynamics (BD) with fluctuating hydrodynamic interactions. Applying these methods to the same physical system (a single polymer chain in a good solvent in thermal equilibrium) allows us to draw a detailed and quantitative comparison in terms of both accuracy and efficiency. It is found that the static conformations of the LB model are distorted when the box length L is too small compared to the chain size. Furthermore, some dynamic properties of the LB model are subject to an L−1 finite-size effect, while the BD model directly reproduces the asymptotic L→∞ behavior. Apart from these finite-size effects, it is also found that in order to obtain the correct dynamic properties for the LB simulations, it is crucial to properly thermalize all the kinetic modes. Only in this case, the results are in excellent agreement with each other, as expected. Moreover, Brownian dynamics is found to be much more efficient than lattice Boltzmann as long as the degree of polymerization is not excessively large.
Theory of Filtration
Publisher: Springer Netherlands
Date: 1987
Collapse Dynamics of Copolymers in a Poor Solvent: Influence of Hydrodynamic Interactions and Chain Sequence
Publisher: American Chemical Society (ACS)
Date: 11-11-2010
DOI: 10.1021/MA101806N
Shear thinning in dilute and semidilute solutions of polystyrene and DNA
Publisher: Society of Rheology
Date: 07-2018
DOI: 10.1122/1.5010203
Universal viscometric functions for dilute polymer solutions
Publisher: Elsevier BV
Date: 08-1997
Universal Behavior of Dendrimer Solutions
Publisher: American Chemical Society (ACS)
Date: 12-01-2011
DOI: 10.1021/MA102094F
Multiscale simulation of dilute DNA in a roll-knife coating flow
Publisher: Society of Rheology
Date: 11-2008
DOI: 10.1122/1.2994729
Size, shape, and diffusivity of a single Debye-Hückel polyelectrolyte chain in solution
Publisher: AIP Publishing
Date: 13-08-2015
DOI: 10.1063/1.4928458
Abstract: Brownian dynamics simulations of a coarse-grained bead-spring chain model, with Debye-Hückel electrostatic interactions between the beads, are used to determine the root-mean-square end-to-end vector, the radius of gyration, and various shape functions (defined in terms of eigenvalues of the radius of gyration tensor) of a weakly charged polyelectrolyte chain in solution, in the limit of low polymer concentration. The long-time diffusivity is calculated from the mean square displacement of the centre of mass of the chain, with hydrodynamic interactions taken into account through the incorporation of the Rotne-Prager-Yamakawa tensor. Simulation results are interpreted in the light of the Odjik, Skolnick, Fixman, Khokhlov, and Khachaturian blob scaling theory (Everaers et al., Eur. Phys. J. E 8, 3 (2002)) which predicts that all solution properties are determined by just two scaling variables—the number of electrostatic blobs X and the reduced Debye screening length, Y. We identify three broad regimes, the ideal chain regime at small values of Y, the blob-pole regime at large values of Y, and the crossover regime at intermediate values of Y, within which the mean size, shape, and diffusivity exhibit characteristic behaviours. In particular, when simulation results are recast in terms of blob scaling variables, universal behaviour independent of the choice of bead-spring chain parameters, and the number of blobs X, is observed in the ideal chain regime and in much of the crossover regime, while the existence of logarithmic corrections to scaling in the blob-pole regime leads to non-universal behaviour.
Rheological consequences of wet and dry friction in a dumbbell model with hydrodynamic interactions and internal viscosity
Publisher: AIP Publishing
Date: 06-09-2018
DOI: 10.1063/1.5040397
Abstract: The effect of fluctuating internal viscosity and hydrodynamic interactions on a range of rheological properties of dilute polymer solutions is examined using a finitely extensible dumbbell model for a polymer. Brownian dynamics simulations are used to compute both transient and steady state viscometric functions in shear flow. The results enable a careful differentiation of the influence, on rheological properties, of solvent-mediated friction from that of a dissipative mechanism that is independent of solvent viscosity. In particular, hydrodynamic interactions have a significant influence on the magnitude of the stress jump at the inception of shear flow, and on the transient viscometric functions, but a negligible effect on the steady state viscometric functions at high shear rates. Zero-shear rate viscometric functions of free-draining dumbbells remain essentially independent of the internal viscosity parameter, as predicted by the Gaussian approximation, but the inclusion of hydrodynamic interactions induces a dependence on both the hydrodynamic interaction and the internal viscosity parameter. Large values of the internal viscosity parameter lead to linear viscoelastic predictions that mimic the behavior of rigid dumbbell solutions. On the other hand, steady-shear viscometric functions at high shear rates differ in general from those for rigid dumbbells, depending crucially on the finite extensibility of the dumbbell spring.
Exploring the universal dynamics of dilute polymer solutions in extensional flows
Publisher: Elsevier BV
Date: 08-2004
Universal solvent quality crossover of the zero shear rate viscosity of semidilute DNA solutions
Publisher: Society of Rheology
Date: 03-2014
DOI: 10.1122/1.4861072
Multiplicative separation of the influences of excluded volume, hydrodynamic interactions and finite extensibility on the rheological properties of dilute polymer solutions
Publisher: Elsevier BV
Date: 2004
Universal scaling and characterization of gelation in associative polymer solutions
Publisher: Society of Rheology
Date: 24-05-2021
DOI: 10.1122/8.0000235
Abstract: A multiparticle Brownian dynamics simulation algorithm with a Soddemann–Dünweg–Kremer potential that accounts for pairwise excluded volume interactions between both backbone monomers and associating groups (stickers) on a chain is used to describe the static behavior of associative polymer solutions, across a range of concentrations into the semidilute unentangled regime. Predictions for the fractions of stickers bound by intrachain and interchain associations, as a function of system parameters such as the number of stickers on a chain, the number of backbone monomers between stickers, the solvent quality, and monomer concentration, are obtained. A systematic comparison between simulation results and scaling relations predicted by the mean-field theory of Dobrynin [Macromolecules 37, 3881–3893 (2004)] is carried out. Different regimes of scaling behavior are identified by the theory depending on the monomer concentration, the density of stickers on a chain, and whether the solvent quality for the backbone monomers corresponds to θ or good solvent conditions. Simulation results validate the predictions of the mean-field theory across a wide range of parameter values in all the scaling regimes. The value of the des Cloizeaux exponent, θ2=1/3, proposed by Dobrynin for sticky polymer solutions, is shown to lead to a collapse of simulation data for all the scaling relations considered here. Three different signatures for the characterization of gelation are identified, with each leading to a different value of the concentration at the solgel transition. The Flory–Stockmayer expression relating the degree of interchain conversion at the solgel transition to the number of stickers on a chain, modified by Dobrynin to account for the presence of intrachain associations, is found to be validated by simulations for all three gelation signatures. Simulation results confirm the prediction of scaling theory for the gelation line that separates sol and gel phases, when the modified Flory–Stockmayer expression is used. Phase separation is found to occur with increasing concentration for systems in which the backbone monomers are under θ-solvent conditions and is shown to coincide with a breakdown in the predictions of scaling theory.
Equilibrium Swelling and Universal Ratios in Dilute Polymer Solutions: Exact Brownian Dynamics Simulations for a Delta Function Excluded Volume Potential
Publisher: American Chemical Society (ACS)
Date: 12-09-2003
DOI: 10.1021/MA034296F
Effect of stretching-induced changes in hydrodynamic screening on coil-stretch hysteresis of unentangled polymer solutions
Publisher: American Physical Society (APS)
Date: 05-01-2017
Hysteresis and Metastability in a Continuum Sandpile Model
Publisher: American Physical Society (APS)
Date: 03-1995
Viscometric functions and rheo-optical properties of dilute polymer solutions: Comparison of FENE-Fraenkel dumbbells with rodlike models
Publisher: Elsevier BV
Date: 11-2020
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