Journal of Rheology最新文献_第5页

Effect of polydispersity and bubble clustering on the steady shear viscosity of semidilute bubble suspensions in Newtonian media 多分散性和气泡聚类对牛顿介质中半稀气泡悬浮液稳定剪切粘度的影响

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-01 DOI: 10.1122/8.0000585

Stamatina Mitrou, S. Migliozzi, P. Angeli, L. Mazzei

{"title":"Effect of polydispersity and bubble clustering on the steady shear viscosity of semidilute bubble suspensions in Newtonian media","authors":"Stamatina Mitrou, S. Migliozzi, P. Angeli, L. Mazzei","doi":"10.1122/8.0000585","DOIUrl":"https://doi.org/10.1122/8.0000585","url":null,"abstract":"In this work, we examine the steady shear rheology of semidilute polydisperse bubble suspensions to elucidate the role of polydispersity on the viscosity of these systems. We prove theoretically that the effect of polydispersity on suspension viscosity becomes apparent only if the bubble size distribution is bimodal, with very small and very large bubbles having similar volume fractions. In any other case, we can consider the polydisperse suspension as monodisperse, with the average bubble diameter equal to the De Brouckere mean diameter ([Formula: see text]). To confirm the theoretical results, we carried out steady shear rheological tests. Our measurements revealed an unexpected double power-law decay of the suspension relative viscosity at average capillary numbers between 0.01 and 1. To investigate this behavior further, we visualized the produced bubble suspensions under shear. The visualization experiments revealed that bubbles started forming clusters and threads at an average capillary number around 0.01, where we observed the first decay of viscosity. Clustering and alignment have been associated with shear-thinning behavior in particle suspensions. We believe that the same holds for bubble suspensions, where bubble clusters and threads align with the imposed shear flow, reducing the streamline distortions and, in turn, resulting in a decrease in the suspension viscosity. Consequently, we can attribute the first decay of the relative viscosity to the formation of bubble clusters and threads, proving that the novel shear-thinning behavior we observed is due to a combination of bubble clustering and deformation.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41493248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Erratum: “Tensorial formulations for improved thixotropic viscoelastic modeling of human blood” [J. Rheol. 66, 327 (2022)] 勘误:“改进的人体血液触变粘弹性模型的张量公式”[J]。中华医学杂志，2016,327 (2022)[j]

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-01 DOI: 10.1122/8.0000662

M. Armstrong, Andre Pincot, S. Jariwala, Jeffrey S. Horner, Norman Wagner, A. Beris

引用次数: 0

Characterizing the rheology of lamellar gel networks with optical coherence tomography velocimetry 用光学相干断层扫描测速法表征层状凝胶网络的流变性

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-01 DOI: 10.1122/8.0000599

Owen Watts Moore, T. Waigh, Cesar Mendoza, A. Kowalski

引用次数: 1

Rigid rod particle like viscoelastic responses of poly(vinylidene fluoride) in N-methylpyrrolidone solution 聚偏氟乙烯在n -甲基吡咯烷酮溶液中的粘弹性响应

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-01 DOI: 10.1122/8.0000610

Hyota Hozumi, Yuki Nohara, Yoshiki Horikawa, T. Shikata

{"title":"Rigid rod particle like viscoelastic responses of poly(vinylidene fluoride) in N-methylpyrrolidone solution","authors":"Hyota Hozumi, Yuki Nohara, Yoshiki Horikawa, T. Shikata","doi":"10.1122/8.0000610","DOIUrl":"https://doi.org/10.1122/8.0000610","url":null,"abstract":"A systematic study was performed on the dynamic viscoelastic properties of N-methylpyrrolidone (NMP) solutions of poly(vinylidene fluoride) (PVDF) samples with a wide range of weight average molar masses ( Mw) from 140 to 3300 kg mol−1 over a temperature range of −24 to 35 °C in the dilute to semidilute concentration ( c) regime in this study. In previous studies under extremely dilute conditions, it was confirmed that PVDF molecules behave as isolated highly elongated rigid rods, and the average particle length (⟨ L⟩) and diameter (⟨ d⟩) for different PVDF samples were precisely determined. The fundamental viscoelastic parameters used to analyze the dynamics of PVDF molecules dissolved in NMP were precisely determined, including the zero-shear shear viscosity ( η0), the steady state compliance ( Je), the average relaxation time ( τw), and the activation energy ( E*v) of τw in this study. E*v increased stepwise above c values corresponding to the reciprocal of the intrinsic viscosity ([ η]−1) for different solutions, independent of Mw, showing that contact or the formation of entanglements between PVDF molecules causes the increase in E*v. Je−1 was found to be proportional to the number density of PVDF molecules (ν = cNA Mw−1, where NA denotes the Avogadro constant) over the entire investigated v range, irrespective of Mw and the presence of entanglements between PVDF molecules. The reduced specific viscosities, ηsp NA⟨ L⟩3( Mw[ η])−1, were reasonably described as a universal function in the parameter ν⟨ L⟩3 over the entire investigated range, and ηsp NA⟨ L⟩3( Mw[ η])−1 ∝ ( ν⟨ L⟩3)3 was found over the region 102 < ν⟨ L⟩3 < 103, irrespective of Mw.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46638262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evolution of flow reversal and flow heterogeneities in high elasticity wormlike micelles (WLMs) with a yield stress 具有屈服应力的高弹性虫状胶束(WLMs)流动逆转和流动非均质性的演化

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-01 DOI: 10.1122/8.0000535

P. J. McCauley, Christine Huang, L. Porcar, Satish Kumar, M. Calabrese

{"title":"Evolution of flow reversal and flow heterogeneities in high elasticity wormlike micelles (WLMs) with a yield stress","authors":"P. J. McCauley, Christine Huang, L. Porcar, Satish Kumar, M. Calabrese","doi":"10.1122/8.0000535","DOIUrl":"https://doi.org/10.1122/8.0000535","url":null,"abstract":"The formation and evolution of a heterogeneous flow and flow reversal are examined in highly elastic, gel-like wormlike micelles (WLMs) formed from an amphiphilic triblock poloxamer P234 in 2M NaCl. A combination of linear viscoelastic, steady shear, and creep rheology demonstrate that these WLMs have a yield stress and exhibit viscoelastic aging, similar to some soft glassy materials. Nonlinear shear rheology and rheoparticle tracking velocimetry reveal that these poloxamer WLMs undergo a period of strong elastic recoil and flow reversal after the onset of shear startup. As flow reversal subsides, a fluidized high shear rate region and a nearly immobile low shear rate region of fluid form, accompanied by wall slip and elastic instabilities. The features of this flow heterogeneity are reminiscent of those for aging yield stress fluids, where the heterogeneous flow forms during the initial stress overshoot and is sensitive to the inherent stress gradient of the flow geometry. Additionally, macroscopic bands that form transiently above a critical shear rate become “trapped” due to viscoelastic aging in the nearly immobile region. This early onset of the heterogeneous flow during the rapidly decreasing portion of the stress overshoot differs from that typically observed in shear banding WLMs and is proposed to be necessary for observing significant flow reversal. Exploring the early-time, transient behavior of this WLM gel with rheology similar to both WLM solutions and soft glassy materials provides new insights into spatially heterogeneous flows in both of these complex fluids.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44139077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Rheo-electric measurements of carbon black suspensions containing polyvinylidene difluoride in N-methyl-2-pyrrolidone 在n -甲基-2-吡咯烷酮中含有聚偏二氟乙烯的炭黑悬浮液的流变电测量

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-01 DOI: 10.1122/8.0000615

Qingsong Liu, J. J. Richards

{"title":"Rheo-electric measurements of carbon black suspensions containing polyvinylidene difluoride in N-methyl-2-pyrrolidone","authors":"Qingsong Liu, J. J. Richards","doi":"10.1122/8.0000615","DOIUrl":"https://doi.org/10.1122/8.0000615","url":null,"abstract":"Lithium-ion battery cathode slurries have a microstructure that depends sensitively on how they are processed due to carbon black's (CB) evolving structure when subjected coating flows. While polyvinylidene difluoride (PVDF), one of the main components of the cathode slurry, plays an important role in modifying the structure and rheology of CB, a quantitative understanding is lacking. In this work, we explore the role of PVDF in determining the structural evolution of Super C65 CB in N-methyl-2-pyrrolidinone (NMP) with rheo-electric measurements. We find that PVDF enhances the viscosity of NMP resulting in a more extensive structural erosion of CB agglomerates with increasing polymer concentration and molecular weight. We also show that the relative viscosity of all suspensions can be collapsed by the fluid Mason number [Formula: see text], which compares the hydrodynamic forces imposed by the medium to cohesive forces holding CB agglomerates together. Using simultaneous rheo-electric measurements, we find at high [Formula: see text], the dielectric strength [Formula: see text] scales with [Formula: see text], and the power-law scaling can be quantitatively predicted by considering the self-similar break up of CB agglomerates. The collapse of the relative viscosity and scaling of [Formula: see text] both suggest that PVDF increases the hydrodynamic force of the suspending medium without directly changing the CB agglomerate structure. These findings are valuable for optimizing the rheology of lithium ion battery cathode slurries. We also anticipate that these findings can be extended to understand the microstructure of similar systems under flow.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49062181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

A tube model for predicting the stress and dielectric relaxations of polydisperse linear polymers 预测多分散线性聚合物的应力和介电弛豫的管模型

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-01 DOI: 10.1122/8.0000605

Chinmay Das, D. Read

引用次数: 1

A fully physiologically-informed time- and rate-dependent hemorheological constitutive model 一个完全生理信息的时间和速率依赖的血液流变学本构模型

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-04-21 DOI: 10.1122/8.0000552

E. Javadi, M. Armstrong, S. Jamali

{"title":"A fully physiologically-informed time- and rate-dependent hemorheological constitutive model","authors":"E. Javadi, M. Armstrong, S. Jamali","doi":"10.1122/8.0000552","DOIUrl":"https://doi.org/10.1122/8.0000552","url":null,"abstract":"From a mechanical perspective, blood is a complex fluid with a rate- and time-dependent response to an applied deformation. At small deformation rates, cell aggregations owing to the bridging of fibrinogen proteins result in the formation of rouleaux structures manifesting in a large increase in the overall viscosity of the blood viscosity and the emergence of measurable yield stress. At elevated deformation rates, these internal aggregated mesostructures are broken down in a dynamical fashion, giving rise to a thermokinematic memory and thixotropic behavior of the blood. These rich and complex rheological features of blood are primarily governed by the interactions between different cells as well as the fraction of red blood cells (RBCs). Here, using a series of detailed computational tools and benchmarking experimental measurements, we present a constitutive model that accurately describes the rate- and time-dependent rheology of blood based on two physiological metrics of the blood: the hematocrit and fibrinogen concentration. We show that the model is capable of accurately predicting blood flow, not only under simple steady flows but also under different flow protocols relevant to a real circulatory system.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48501240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Rheology of non-Brownian particle suspensions in viscoelastic solutions. Part 1: Effect of the polymer concentration 粘弹性溶液中非布朗颗粒悬浮液的流变学。第一部分:聚合物浓度的影响

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-03-01 DOI: 10.1122/8.0000540

Anni Zhang, E. Shaqfeh

{"title":"Rheology of non-Brownian particle suspensions in viscoelastic solutions. Part 1: Effect of the polymer concentration","authors":"Anni Zhang, E. Shaqfeh","doi":"10.1122/8.0000540","DOIUrl":"https://doi.org/10.1122/8.0000540","url":null,"abstract":"We study the effect of varying polymer concentration, measured by the dimensionless polymer viscosity partition function [Formula: see text], on the steady shear rheology of rigid particle suspensions using direct numerical simulation of the Oldroyd-B model. We compare the bulk rheology using immersed boundary simulations at [Formula: see text] and [Formula: see text] to body-fitted single-particle simulations and find that the per-particle viscosity and first normal stress difference coefficient are always shear-thickening at all values of [Formula: see text] considered. However, as [Formula: see text] decreases, the polymer stress transforms the flow field near each particle from closed concentric streamlines to helical streamlines that advect stretched polymers away from the particle surface. At low [Formula: see text], the polymer stress is diffuse, where the distribution of the particle induced fluid stress (PIFS) caused by the stretched polymers is spread out in the simulation domain rather than concentrated near the particle surface. Therefore in multiparticle simulations, the polymer stress can be significantly affected by particle-particle interactions. The stress generated by a given particle is disrupted by the presence of particles in its vicinity, leading to a significantly lower PIFS than that of the single-particle simulation. In addition, at increased volume fractions and low values of [Formula: see text], the polymer stress distribution on the particle surface shifts so as to increase the magnitude of the polymer stress moments, resulting in a shear-thickening stresslet contribution to the viscosity that is not seen in single particle or high [Formula: see text] simulations. This result indicates that for suspensions in highly viscoelastic suspending fluids that are characterized by a low [Formula: see text] parameter, hydrodynamic interactions are significant even at modest particle concentrations and fully resolved multiparticle simulations are necessary to understand the rheological behavior.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43216451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Tribological variable-friction coefficient models for the simulation of dense suspensions of rough polydisperse particles 粗糙多分散颗粒密集悬浮液模拟的摩擦学变摩擦系数模型

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-03-01 DOI: 10.1122/8.0000514

J. A. Ruíz-López, S. S. Prasanna Kumar, A. Vázquez-Quesada, J. D. de Vicente, M. Ellero

{"title":"Tribological variable-friction coefficient models for the simulation of dense suspensions of rough polydisperse particles","authors":"J. A. Ruíz-López, S. S. Prasanna Kumar, A. Vázquez-Quesada, J. D. de Vicente, M. Ellero","doi":"10.1122/8.0000514","DOIUrl":"https://doi.org/10.1122/8.0000514","url":null,"abstract":"The rheology of concentrated suspensions of particles is complex and typically exhibits a shear-thickening behavior in the case of repulsive interactions. Despite the recent interest arisen, the causes of the shear-thickening remain unclear. Frictional contacts have been able to explain the discontinuous shear thickening in simulations. However, the interparticle friction coefficient is considered to be constant in most simulations and theoretical works reported to date despite the fact that tribological experiments demonstrate that the friction coefficient can not only be constant (boundary regime) but also decrease (mixed regime) or even increase (full-film lubrication regime), depending on the normal force and the relative velocity between the particles and the interstitial liquid between them. Interestingly, the transition between the boundary regime and the full-lubrication regime is governed by the particle average roughness. Particle-level simulations of suspensions of hard spheres were carried out using short-range lubrication and roughness-dependent frictional forces describing the full Stribeck curve. Suspensions with different particle’s roughness were simulated to show that the particle roughness is a key factor in the shear-thickening behavior; for sufficiently rough particles, the suspension exhibits a remarkable shear-thickening, while for sufficiently smooth particles, the discontinuous shear-thickening disappears.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47692169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3