-
Erratum: “Flow-rate based method for velocity of fully developed laminar flow in tubes” [J. Rheol. 62(6), 1397–1407 (2018)] J. Rheol. (IF 3.711) Pub Date : 2021-03-01 Sun Kyoung Kim
Journal of Rheology, Volume 65, Issue 2, Page 289-289, March 2021.
-
Rheology and structure of suspensions of spherocylinders via Brownian dynamics simulations J. Rheol. (IF 3.711) Pub Date : 2021-03-01 Jing-Yao Chen; Zhuohan Li; Izabela Szlufarska; Daniel J. Klingenberg
Brownian dynamics simulations were employed to investigate the rheological properties and structure of suspensions of rigid spherocylinders, as a model for rodlike colloids. The spherocylinders interacted only through a soft repulsive force that mimicked a hard spherocylinder interaction. The translational and rotational diffusivities of hard spherocylinder suspensions were reproduced. Liquid crystalline
-
Apparent wall slip effects on rheometric measurements of waxy gels J. Rheol. (IF 3.711) Pub Date : 2021-02-25 Thiago O. Marinho; Flávio H. Marchesini; Márcia C. K. de Oliveira; Márcio Nele
The effects of apparent wall slip on rheometric measurements of waxy gels are quantified for gels consisting of a macrocrystalline wax added in mineral oil in concentrations of 3.0 and 7.5 wt. %. The waxy gels are formed in situ in a stress-controlled rheometer, and rheological properties are then obtained. Seven different geometry configurations, including parallel plates, concentric cylinders, and
-
Transient dynamics of soft particle glasses in startup shear flow. Part I: Microstructure and time scales J. Rheol. (IF 3.711) Pub Date : 2021-02-22 Fardin Khabaz; Bruno Flavio Di Dio; Michel Cloitre; Roger T. Bonnecaze
The rheology and microstructure of soft particle glasses during startup flow are studied using three-dimensional particle dynamics simulations at different particle volume fractions and shear rates. The behavior of transient stress depends on the applied shear rate. At high shear rates, soft particle glasses exhibit a static yield stress signaled by a stress overshoot followed by a relaxation to a
-
Yield stress behavior of colloidal gels with embedded active particles J. Rheol. (IF 3.711) Pub Date : 2021-02-19 Keara T. Saud; Mahesh Ganesan; Michael J. Solomon
The yield stress behavior of colloidal gels with embedded active particles is studied with three experiments: start-up of steady shear, oscillatory strain amplitude sweep, and creep testing. Activity is generated by Janus particles with a platinum hemisphere; these particles undergo self-diffusiophoretic and self-electrophoretic motion in hydrogen peroxide solutions. The free particle active motion
-
Wall slip in primitive chain network simulations of shear startup of entangled polymers and its effect on the shear stress undershoot J. Rheol. (IF 3.711) Pub Date : 2021-02-19 Yuichi Masubuchi; Dimitris Vlassopoulos; Giovanni Ianniruberto; Giuseppe Marrucci
In some recent experiments on entangled polymers of stress growth in the startup of fast shear flows, an undershoot in the shear stress is observed following the overshoot, i.e., before approaching the steady state. Whereas tumbling of the entangled chain was proposed to be at its origin, here, we investigate another possible cause for the stress undershoot, i.e., slippage at the interface between
-
Wall slip and bulk yielding in soft particle suspensions J. Rheol. (IF 3.711) Pub Date : 2021-02-12 Gerhard Jung; Suzanne M. Fielding
We simulate a dense athermal suspension of soft particles sheared between hard walls of a prescribed roughness profile, fully accounting for the fluid mechanics of the solvent between the particles and for the solid mechanics of changes in the particle shapes. We, thus, capture the widely observed rheological phenomenon of wall slip. For imposed stresses below the material’s bulk yield stress, we show
-
Data-driven physics-informed constitutive metamodeling of complex fluids: A multifidelity neural network (MFNN) framework J. Rheol. (IF 3.711) Pub Date : 2021-02-11 Mohammadamin Mahmoudabadbozchelou; Marco Caggioni; Setareh Shahsavari; William H. Hartt; George Em Karniadakis; Safa Jamali
In this work, we introduce a comprehensive machine-learning algorithm, namely, a multifidelity neural network (MFNN) architecture for data-driven constitutive metamodeling of complex fluids. The physics-based neural networks developed here are informed by the underlying rheological constitutive models through the synthetic generation of low-fidelity model-based data points. The performance of these
-
Rheological and thermal properties of the KF-KCl-K2SiF6 electrolyte for electrolytic production of silicon J. Rheol. (IF 3.711) Pub Date : 2021-02-05 Andrey Isakov; Anastasia Khudorozhkova; Alexander Redkin; Yurii Zaikov
Viscosity and phase transitions were studied in the (KF-KCl)eut.-(10 mol. %)K2SiF6 system. Synchronous thermal analysis (STA) was used to study the phase transformations in the system in the temperature range of 298–1113 K. The (KF-KCl)eut.-(10 mol. %)K2SiF6 melt was found to be homogeneous at 903–993 K. The viscosity of the system under study was investigated by the rotational viscometer FRS 1600
-
Buffered λ-DNA solutions at high shear rates J. Rheol. (IF 3.711) Pub Date : 2021-02-04 H. Dakhil; S. K. Basu; S. Steiner; Y. Gerlach; A. Soller; Sharadwata Pan; Natalie Germann; M. Leidenberger; B. Kappes; A. Wierschem
We study buffered aqueous solutions of deoxyribonucleic acid isolated from bacteriophage lambda (λ-DNA) at shear rates up to 105 s−1. The shear rates are accessed with a narrow-gap rheometer at gap widths down to 20 μm. At lower shear rates, our data merge with the literature values. At high shear rates, the viscosity levels off into an infinite-shear viscosity plateau. Hence, the viscosity functions
-
Direct measurements of the microstructural origin of shear-thinning in carbon black suspensions J. Rheol. (IF 3.711) Pub Date : 2021-01-29 Julie B. Hipp; Jeffrey J. Richards; Norman J. Wagner
Scientific questions surrounding the shear-dependent microstructure of carbon black suspensions are motivated by a desire to predict and control complex rheological and electrical properties encountered under shear. In this work, direct structural measurements over a hierarchy of length scales spanning from nanometers to tens of micrometers are used to determine the microstructural origin of the suspension
-
Revisiting the basis of transient rheological material functions: Insights from recoverable strain measurements J. Rheol. (IF 3.711) Pub Date : 2021-01-27 Piyush K. Singh; Johnny Ching-Wei Lee; Kshitish A. Patankar; Simon A. Rogers
Recent studies have shown that rheological material functions that can be linked to structural measures are defined in terms of the recoverable and unrecoverable strains [for example, Lee et al., Phys. Rev. Lett. 122, 248003 (2019)]. In this study, we explore the consequences of applying these ideas to transient nonlinear rheological tests, using new material functions including an elastic modulus
-
An orientation-stretch coupled model for entangled comb polymers J. Rheol. (IF 3.711) Pub Date : 2021-01-22 Zhongqiang Xiong; Wei Yu
A semi-empirical constitutive equation is suggested for the model comb polymer with the purpose to simultaneously describe the intrinsic medium amplitude oscillatory shear (MAOS) behaviors and transient behaviors in start-up elongational experiments. The molecular stress and hierarchical relaxation of comb polymers are discussed on the basis of the orientation-stretch coupled conformation tensor of
-
Electrorheological behaviors of waxy crude oil gel J. Rheol. (IF 3.711) Pub Date : 2021-01-11 Qian Huang; Hongying Li; Yiwei Xie; Yifei Ding; Yu Zhuang; Chaohui Chen; Shanpeng Han; Jinjun Zhang
The paraffin molecules in crude oil crystalize and precipitate out as the oil cools, resulting in a sharp increase in oil viscosity and further the gelation of the oil. The waxy crude oil gel exhibits complex rheological behaviors, such as viscoelasticity, yield stress, and thixotropy, posing challenges to the flow assurance of pipelines. Previous studies have verified that applying a high-voltage
-
Linear viscoelasticity and time-temperature-salt and other superpositions in polyelectrolyte coacervates J. Rheol. (IF 3.711) Pub Date : 2021-01-06 Ronald G. Larson; Ying Liu; Huiling Li
The linear viscoelasticity of coacervates formed by oppositely charged polyelectrolytes in the salt solution is reviewed, with a focus on time-temperature, time-salt, time-pH, and time-hydration superpositions, and on fundamental relaxation mechanisms. A variety of polyelectrolyte pairs are covered, showing the frequent, but not universal, success of the time-salt superposition. Master curves in many
-
Erratum: “Modelling the rheology of thixotropic elasto-visco-plastic materials” [J. Rheol. 63(4), 609–639 (2019)] J. Rheol. (IF 3.711) Pub Date : 2020-12-18 S. Varchanis; G. Makrigiorgos; P. Moschopoulos; Y. Dimakopoulos; J. Tsamopoulos
Journal of Rheology, Volume 65, Issue 1, Page 75-75, January 2021.
-
Erratum: “A slip-spring simulation model for predicting linear and nonlinear rheology of entangled wormlike micellar solutions” [J. Rheol. 64, 1045 (2020)] J. Rheol. (IF 3.711) Pub Date : 2020-12-18 Takeshi Sato; Soroush Moghadam; Grace Tan; Ronald G. Larson
Journal of Rheology, Volume 65, Issue 1, Page 73-73, January 2021.
-
Determining threadlike micelle lengths from rheometry J. Rheol. (IF 3.711) Pub Date : 2020-12-18 Grace Tan; Weizhong Zou; Mike Weaver; Ronald G. Larson
We show that the average length ⟨ L ⟩ of threadlike micelles in surfactant solutions predicted by fitting results of a mesoscopic simulation, the “pointer algorithm,” to experimental G′(ω), G″(ω) data, is longer than, and more accurate than, that from a scaling law that equates ⟨ L ⟩ / l e to the modulus ratio G 0 / G m i n ′ ′. Here, G0 is the plateau modulus, G m i n ′ ′ is obtained at the local
-
Strategy for reducing molecular ensemble size for efficient rheological modeling of commercial polymers J. Rheol. (IF 3.711) Pub Date : 2020-12-10 Yanan Gong; Valeriy Ginzburg; Sylvie Vervoort; Jaap Den Doelder; Ronald G. Larson
We develop a method for efficient prediction of linear and nonlinear rheology of polydisperse polymers by judicious selection of a small number of representative polymer molecules from the large ensemble of chains comprising the molecular weight and branching distribution. Specifically, we use a numerical inversion of the double reptation model to select five or six representative molecular species
-
Non-Newtonian modeling of contact pressure in fused filament fabrication J. Rheol. (IF 3.711) Pub Date : 2020-12-10 Sun Kyoung Kim; David O. Kazmer; Austin R. Colon; Timothy J. Coogan; Amy M. Peterson
The nozzle pressure was monitored in a fused filament fabrication process for the printing of high impact polystyrene. The contact pressure, defined as the pressure applied by the newly deposited layer onto the previous layer, is experimentally calculated as the difference between the pressure during printing and open discharge at the same volumetric flow rates. An analytical method for estimating
-
The zero-shear-rate limiting rheological behaviors of ideally conductive particles suspended in concentrated dispersions under an electric field J. Rheol. (IF 3.711) Pub Date : 2020-11-25 Siamak Mirfendereski; Jae Sung Park
The rheological behaviors of suspension of ideally conductive particles in an electric field are studied using large-scale numerical simulations in the limit of the zero-shear-rate flow. Under the action of an electric field, the particles undergo the nonlinear electrokinetic phenomenon termed dipolophoresis, which is the combination of dielectrophoresis and induced-charge electrophoresis. For ideally
-
Rheological responses of particle-filled polymer solutions: The transition to linear-nonlinear dichotomy J. Rheol. (IF 3.711) Pub Date : 2020-11-20 Jinying Zou; Xiaorong Wang
We found an anomalous nonlinear behavior under large amplitude oscillatory shears, where the amplitude stress deviates strongly from the linear dependence of strain, while the time dependence of stress remains sinusoidal. This phenomenon is usually accompanied with the Payne effect of filled rubbers. In order to understand the molecular details regarding this unusual behavior, we examined a series
-
Rheology discussions: The physics of dense suspensions J. Rheol. (IF 3.711) Pub Date : 2020-11-16 Safa Jamali; Emanuela Del Gado; Jeffrey F. Morris
Journal of Rheology, Volume 64, Issue 6, Page 1501-1524, November 2020.
-
Comment on “A revisitation of generalized Newtonian fluids” [J. Rheol. 64, 493–504 (2020)] J. Rheol. (IF 3.711) Pub Date : 2020-11-16 Jang Min Park
Journal of Rheology, Volume 64, Issue 6, Page 1497-1499, November 2020.
-
A full-chain tube-based constitutive model for living linear polymers J. Rheol. (IF 3.711) Pub Date : 2020-11-16 J. D. Peterson; M. E. Cates
We present a new strategy for introducing population balances into full-chain constitutive models of living polymers with linear chain architectures. We provide equations to describe a range of stress relaxation processes covering both unentangled systems (Rouse-like motion) and well-entangled systems (reptation, contour length fluctuations, chain retraction, and constraint release). Special attention
-
Temperature, time, pressure, and CO2 concentration dependence of rheological properties for poly(methyl methacrylate)/expanded graphite composites J. Rheol. (IF 3.711) Pub Date : 2020-10-28 Han-Xiong Huang; Li-Min Yu
The effects of temperature, pressure, and supercritical carbon dioxide (scCO2) concentration are investigated on the rheological behavior of poly(methyl methacrylate)/expanded graphite (PMMA/EG) composites with 1, 4, and 7 wt. % EG. The validity of the time-temperature superposition and time-pressure-scCO2 concentration superposition principles for the PMMA/EG composites is explored. At atmospheric
-
General fractional models for linear viscoelastic characterization of asphalt cements J. Rheol. (IF 3.711) Pub Date : 2020-10-28 Wei Cao
Rheological models based on fractional order derivatives have been applied to characterize the linear viscoelasticity of asphalt cements for a long time. Such models provide continuous spectra which are fundamentally related to the molecular characteristics and facilitate analytical investigations as compared to discrete representations. With the increasing complexity in asphalt composition to satisfy
-
Rheology of end-linking polydimethylsiloxane networks filled with silica J. Rheol. (IF 3.711) Pub Date : 2020-10-26 Huilong Xu; Lin Ding; Yihu Song; Wanjie Wang
Filled vulcanizates exhibit the nonlinear Payne effect under dynamic deformations at high strain amplitudes, while the underlining mechanisms are still in dispute. Herein, polydimethylsiloxane (PDMS) networks are prepared via end-linking of α,ω-vinyl-terminated PDMS chains by the thiol-ene reaction, and the influences of silica on the dynamic rheological responses are investigated. The presence of
-
The weakly nonlinear response and nonaffine interpretation of the Johnson–Segalman/Gordon–Schowalter model J. Rheol. (IF 3.711) Pub Date : 2020-10-20 Nabil Ramlawi; N. Ashwin Bharadwaj; Randy H. Ewoldt
We derive new analytical solutions for the nonaffine Johnson–Segalman/Gordon–Schowalter (JS/GS) constitutive equation with a general relaxation kernel in medium-amplitude oscillatory shear (MAOS) deformation. The results show time-strain separable (TSS) nonlinearity, therefore providing new physically meaningful interpretation to the heuristic TSS nonlinear parameter in MAOS [Martinetti and Ewoldt
-
Shear induced demixing in bidisperse and polydisperse polymer blends: Predictions from a multifluid model J. Rheol. (IF 3.711) Pub Date : 2020-10-13 Joseph D. Peterson; Glenn H. Fredrickson; L. Gary Leal
In light of recent advancements in the constitutive modeling of bidisperse and polydisperse entangled linear polymers, we present a new “multifluid” generalization of the classic two-fluid approximation for flows of inhomogeneous polymer blends. As an application of the model, we consider predictions for the linear and nonlinear dynamics of shear induced demixing (SID) instabilities in blends with
-
Rheology of crystallizing LLDPE J. Rheol. (IF 3.711) Pub Date : 2020-10-08 Marat Andreev; David A. Nicholson; Anthony Kotula; Jonathan D. Moore; Jaap den Doelder; Gregory C. Rutledge
Polymer crystallization occurs in many plastic manufacturing processes, from injection molding to film blowing. Linear low-density polyethylene (LLDPE) is one of the most commonly processed polymers, wherein the type and extent of short-chain branching (SCB) may be varied to influence crystallization. In this work, we report simultaneous measurements of the rheology and Raman spectra, using a Rheo-Raman
-
Chain tension reduces monomer friction in simulated polymer melts J. Rheol. (IF 3.711) Pub Date : 2020-10-08 Sai Vineeth Bobbili; Scott T. Milner
The monomer friction coefficient ζ is known to vary with monomer structure, solvent, and concentration; its variation with chain conformation is less well known and appreciated. We explore the decrease of the friction coefficient in the extensional flow of polymer liquids, during which chains become partially stretched and aligned. To induce stretching and alignment similar to the extensional flow
-
Selective distribution of nanoparticles in immiscible blends: Effects on the morphology evolution and rheology in quiescent annealing, shear and extensional flow J. Rheol. (IF 3.711) Pub Date : 2020-10-05 Xiaoyi Zhu; Miqiu Kong; Yadong Lv; Yajiang Huang; Guangxian Li
Nanoparticles (NPs) distributed near the interface (in the droplets/matrix) and exactly at the interface are constructed in model polypropylene/polystyrene blends filled with different hydrophobic silica. It is found that the initially refined morphology of blends is stabilized under quiescent annealing by all NPs, especially for NPs exactly at the interface. However, the refined morphology in the
-
Effect of nitrogen doping on medium-amplitude oscillatory shear (MAOS) response of nanotube/polyvinylidene fluoride nanocomposites: Molecular simulations, rheology, and broadband electrical conductivity J. Rheol. (IF 3.711) Pub Date : 2020-10-01 Soheil Sadeghi; Mohammad Arjmand; Ivonne Otero Navas; Uttandaraman Sundararaj
This study sheds light on the effect of nitrogen (N) doping of carbon nanotubes (CNTs) on medium-amplitude oscillatory shear (MAOS) response of CNT/polyvinylidene fluoride (PVDF) nanocomposites within a rheologically percolated concentration regime. Custom-synthesized CNTs without and with nitrogen heteroatom (at a nitrogen atomic percent of 3.85 at. %) were incorporated into a PVDF matrix using a
-
Rheology of thermoplastic vulcanizates (TPVs) J. Rheol. (IF 3.711) Pub Date : 2020-10-01 Nikoo Ghahramani; Krishnan A. Iyer; Antonios K. Doufas; Savvas G. Hatzikiriakos
Thermoplastic vulcanizates (TPVs) are a special class of polymer blends comprised of a thermoplastic polypropylene (PP) matrix and a dynamically vulcanized ethylene propylene diene monomer (EPDM) rubber. Due to the presence of crosslinked rubber particles, TPVs exhibit complex rheological fingerprints similar to those of soft elastic solids. In this study, we attempt to draw a correlation between the
-
Stress relaxation of entangled ring polymer chains in a linear matrix J. Rheol. (IF 3.711) Pub Date : 2020-10-01 Ji-Xuan Hou
We theoretically study the stress relaxation process of small amounts of entangled ring polymer chains in a linear matrix by combining several important physical mechanisms: (1) Rouse relaxation, (2) longitudinal stress relaxation along the tube, and (3) constraint release. The contribution to stress relaxation of entangled rings by longitudinal modes is calculated analytically, and a compact expression
-
Universal viscosifying behavior of acrylamide-based polymers used in enhanced oil recovery J. Rheol. (IF 3.711) Pub Date : 2020-09-14 S. Jouenne; B. Levache
Conventional polymers used in enhanced oil recovery (EOR) are acrylamide-based copolymers of very high molecular weight. Their viscosity in aqueous solution depends on various physicochemical parameters such as monomer composition, concentration, average molecular weight, polydispersity, salinity level and ionic composition, temperature, etc. Moreover, solutions are non-Newtonian; they exhibit low-shear
-
Medium amplitude parallel superposition (MAPS) rheology. Part 2: Experimental protocols and data analysis J. Rheol. (IF 3.711) Pub Date : 2020-09-11 Kyle R. Lennon; Michela Geri; Gareth H. McKinley; James W. Swan
An experimental protocol is developed to directly measure the new material functions revealed by medium amplitude parallel superposition (MAPS) rheology. This protocol measures the medium amplitude response of a material to a simple shear deformation composed of three sine waves at different frequencies, revealing a rich dataset consisting of up to 19 measurements of the third-order complex modulus
-
Inhomogeneous chain relaxation of entangled polymer melts from stepwise planar extension in absence of free surface J. Rheol. (IF 3.711) Pub Date : 2020-09-09 Ruchao Yuan; Shi-Qing Wang
In this work, we apply lubricated squeezing to perform planar extension of styrene-butadiene rubbers (SBRs) and illustrate how large step-strained SBR undergo chain relaxation. When the imposed step strain is moderate or the stepwise planar extension is imposed sufficiently slowly, the stress relaxation is spatially uniform. Upon a large stepwise extension imposed over a period much shorter than the
-
Irreversible time dependence of gelled waxy crude oils: Flow experiments and modeling J. Rheol. (IF 3.711) Pub Date : 2020-09-03 Behbood Abedi; Elias C. Rodrigues; Paulo R. de Souza Mendes
We introduce a constitutive model to describe the rheological behavior of gelled waxy crude oil. The irreversible time-dependence effects were experimentally characterized and incorporated into the model. The model is developed with basis on the data of standard rheological tests to determine the parameters of novel material functions that arise in the model development procedure, namely, flow curve
-
The slumping of a cohesive granular column: Continuum and discrete modeling J. Rheol. (IF 3.711) Pub Date : 2020-09-03 Anaïs Abramian; Lydie Staron; Pierre-Yves Lagrée
Cohesion forces strongly alter the flow properties of a granular material. To investigate this influence, we focus on a simple configuration: the collapse of a cohesive granular column. To do so, we adopt a numerical approach and implement a peculiar rheology in a Navier–Stokes solver (Basilisk): the so-called μ ( I )-rheology, usually used for dry granular materials, supplemented by a yield stress
-
Mechanisms of two-step yielding in attractive colloidal glasses J. Rheol. (IF 3.711) Pub Date : 2020-09-03 Esmaeel Moghimi; George Petekidis
A combination of experiments and Brownian Dynamics simulations is utilized to examine the mechanisms of yielding and flow in attractive colloidal glasses during start-up shear flow. In both experiments and simulations, the transient stress exhibits two stress peaks indicative of two-step yielding processes. The first yield depends largely on details of interparticle potential whereas the second yield
-
Analysis of linear viscoelasticity of aging soft glasses J. Rheol. (IF 3.711) Pub Date : 2020-09-01 Asheesh Shukla; Sachin Shanbhag; Yogesh M. Joshi
Aging soft glassy materials do not follow time-translational invariance and violate the principles of linear viscoelasticity, such as the relation between the dynamic moduli in the frequency domain and the stress relaxation modulus in the time domain. Using an aqueous suspension of hectorite clay, a model aging soft glassy material, we account for time-dependent behavior by transforming the experimentally
-
Dilatancy in dense suspensions of model hard-sphere-like colloids under shear and extensional flow J. Rheol. (IF 3.711) Pub Date : 2020-09-01 Ricardo J. E. Andrade; Alan R. Jacob; Francisco J. Galindo-Rosales; Laura Campo-Deaño; Qian Huang; Ole Hassager; George Petekidis
Dense suspensions of model hard-sphere (HS)-like colloids, with different particle sizes, are examined experimentally near and in the glass state, under shear and extensional rheology. Under steady shear flow, we detect both continuous and discontinuous shear thickening (DST) above a critical shear rate (or shear stress), depending on the particle size and volume fraction. Start-up shear experiments
-
Effects of elasticity and flow ramp up on kinetics of shear banding flow formation in wormlike micellar fluids J. Rheol. (IF 3.711) Pub Date : 2020-08-28 Peter Rassolov; Hadi Mohammadigoushki
We report experiments on spatiotemporal evolution of the velocity profiles in shear-banding wormlike micelles upon inception of the flow in a Taylor–Couette (TC) cell. Both moderately entangled and highly entangled solutions are considered over a broad range of fluid elasticity E. Fluid elasticity, E = Wi/Re, characterizes the relative importance of the elastic to inertial effects. For both moderately
-
Interplay of edge fracture and shear banding in complex fluids J. Rheol. (IF 3.711) Pub Date : 2020-08-28 Ewan J. Hemingway; Suzanne M. Fielding
We explore theoretically the interplay between shear banding and edge fracture in complex fluids by performing a detailed simulation study within two constitutive models: the Johnson–Segalman model and the Giesekus model. We consider separately parameter regimes in which the underlying constitutive curve is monotonic and nonmonotonic, such that the bulk flow (in the absence of any edge effects) is
-
Rheology and granular texture of viscoinertial simple shear flows J. Rheol. (IF 3.711) Pub Date : 2020-08-27 Thanh-Trung Vo
By means of extensive particle dynamics simulations in a three-dimensional model, we analyze the rheology and granular texture in the steady-state of the viscoinertial granular flow. The interactions between dry particles are added by the theoretical description of the capillary cohesion forces and viscous forces due to the presence of the viscous liquid bridge. We show that the rheology of such flow
-
Flow driven transitions of polyelectrolytes J. Rheol. (IF 3.711) Pub Date : 2020-08-26 Sunil P. Singh; Roland G. Winkler
The nonequilibrium properties of uniformly charged linear polymers in the presence of explicit counterions under shear flow are studied by coarse-grained mesoscale hydrodynamics simulations. The conformational properties of the polyelectrolyte (PE) are quantified by the gyration tensor, the distribution of the end-to-end distance, and alignment with the flow, which display rather universal behavior
-
A constitutive model for sheared dense suspensions of rough particles J. Rheol. (IF 3.711) Pub Date : 2020-08-14 R. V. More; A. M. Ardekani
In a concentrated suspension, particles come into contact due to the presence of asperities on their surfaces. As a result, the contact forces and interparticle friction become one of the important factors governing the rheology of rigid particle suspensions at high concentrations. We show that a load-dependent friction model can be used to reproduce the experimentally observed shear thickening [ST—continuous
-
Two-species models for the rheology of associative polymer solutions: Derivation from nonequilibrium thermodynamics J. Rheol. (IF 3.711) Pub Date : 2020-07-14 Pavlos S. Stephanou; Ioanna Ch. Tsimouri; Vlasis G. Mavrantzas
We show how two-species models, already proposed for the rheology of networks of associative polymer solutions, can be derived from nonequilibrium thermodynamics using the generalized bracket formalism. The two species refer to bridges and (temporary) dangling chains, both of which are represented as dumbbells. Creation and destruction of bridges in our model are accommodated self-consistently by assuming
-
Thermorheological complexity of poly(vinyl alcohol)/borax aqueous solutions J. Rheol. (IF 3.711) Pub Date : 2020-07-10 Jingjing Li; Xiao Cao; Yonggang Liu; Quan Chen
Thermorheological behavior was examined for poly(vinyl alcohol) (PVA) and borax aqueous solutions. The PVA content was fixed to be approximately four times the entanglement concentration, and the borax concentration Cborax was varied in a wide range of 0–10.4 mM. In this system, borate ions yielded from the hydrolysis of borax can crosslink the PVA chains to form a reversible network. At low Cborax = 2
-
Modeling of the rheological properties of multinanolayer films in the presence of compatibilized interphase J. Rheol. (IF 3.711) Pub Date : 2020-06-30 Q. Beuguel; A. Guinault; F. Chinesta; C. Sollogoub; G. Miquelard-Garnier
Rheological behavior of nanolayered films of polyethylene/polyamide 6 (PE/PA6) compatibilized in situ during the coextrusion process has been studied at a temperature between the melting temperatures of PE and PA6. Thanks to the high number of interfaces, a drastic increase in dynamic moduli has been measured when increasing the interphase volume fraction in the films, and a solid-like behavior for
-
Microrheological approach for the viscoelastic response of gels J. Rheol. (IF 3.711) Pub Date : 2020-06-19 L. G. Rizzi
In this paper, I present a simple and self-consistent framework based on microrheology that allows one to obtain the mechanical response of viscoelastic fluids and gels from the motion of probe particles immersed on it. By considering a non-Markovian Langevin equation, I obtain general expressions for the mean-squared displacement and the time-dependent diffusion coefficient that are directly related
-
Yielding, thixotropy, and strain stiffening of aqueous carbon black suspensions J. Rheol. (IF 3.711) Pub Date : 2020-06-18 E. N’gouamba; J. Goyon; L. Tocquer; T. Oerther; P. Coussot
We study experimentally the rheological behavior of carbon black (CB) suspensions in water at different ionic strengths and concentrations. We show by means of standard rheometry completed by local magnetic resonance imaging-rheometry that these suspensions first appear to be thixotropic yield stress fluids: they exhibit a yield stress increasing with the time of rest, their apparent viscosity decreases
-
Influence of interchain interactions on the tumbling of chains in a polymer melt during shear flow J. Rheol. (IF 3.711) Pub Date : 2020-06-16 Tingyu Xu; Xiaoliang Tang; Fucheng Tian; Wei Chen; Liangbin Li
Polymer chains in both dilute solutions and melts undergo cyclic rotation and retraction, which is known as tumbling, under steady shear flow. However, it is still not known how the individual molecules in melts rotate freely under the constraints caused by surrounding chains. In this work, a Brownian dynamics simulation is used to investigate the influences of the interchain interactions on the polymer
-
Fracture strain of composite with nonuniformly distributed reinforcing fibers J. Rheol. (IF 3.711) Pub Date : 2020-06-12 Tetsuya Yamamoto; Yuichi Masubuchi; Masao Doi
It is not straightforward to prepare a fiber reinforced composite in which reinforcing fibers are dispersed uniformly. The nonuniform distribution of the reinforcing fibers produces nonuniform viscosity of the composite and thus drives the breakup of the filament upon extension. However, this breakup is suppressed when the fiber length is large. By using Bachelor’s theory for the viscosity of fiber
-
Oscillatory strain with superposed steady shearing in noncolloidal suspensions J. Rheol. (IF 3.711) Pub Date : 2020-07-29 Arif Mahmud; Shaocong Dai; Roger I. Tanner
The rheology of noncolloidal suspensions in superposed simple shearing and oscillatory shearing was explored. With a Newtonian matrix fluid, one would expect that G′ would be zero in an oscillatory flow, but this was not found; the action of Coulomb friction between the particles appears to cause an increment of G′ at lower frequencies. To understand this frictional effect, measurements of small and
-
Non-Brownian Newtonian suspensions may be rate dependent in time sweep oscillatory shear flow J. Rheol. (IF 3.711) Pub Date : 2020-07-29 Raffaella Martone; Claudia Carotenuto; Mario Minale
A non-Brownian, inertialess, dense suspension of rigid hollow glass spheres is studied with time sweep oscillatory experiments. The measured apparent complex viscosity is shown to depend on the amplitude of the applied strain, in agreement with the literature, and, unexpectedly, also on the angular frequency. Two different regimes are individuated depending on the applied strain. For values smaller
-
Determination of intrinsic viscosity of native cellulose solutions in ionic liquids J. Rheol. (IF 3.711) Pub Date : 2020-07-24 Nyalaliska W. Utomo; Behzad Nazari; Daniele Parisi; Ralph H. Colby
The weight-average molecular weights of six native cellulose samples in ionic liquids were determined through steady shear viscosity measurements in the ionic liquid butyl methyl imidazolium chloride. The intrinsic viscosity [ η ] in ethyl methyl imidazolium acetate (EMImAc) is measured using a gravity-driven glass capillary viscometer and found to be independent of temperature in the range of 30–80 °C
-
A slip-spring simulation model for predicting linear and nonlinear rheology of entangled wormlike micellar solutions J. Rheol. (IF 3.711) Pub Date : 2020-07-22 Takeshi Sato; Soroush Moghadam; Grace Tan; Ronald G. Larson
We extend the single-chain slip-spring model developed by Likhtman [Macromolecules 38, 6128 (2005)] to describe the dynamics and rheology of entangled polymers to wormlike micellar solutions by incorporating chain breakage and rejoining, which are the key additional dynamics present in wormlike micellar solutions. We show that the linear rheological properties obtained from this micelle slip-spring
Contents have been reproduced by permission of the publishers.