Journal of Rheology最新文献

{"title":"Cohesive granular columns collapsing: Numerics questioning failure, cohesion, and friction","authors":"L. Staron, L. Duchemin, P. Lagrée","doi":"10.1122/8.0000674","DOIUrl":"https://doi.org/10.1122/8.0000674","url":null,"abstract":"Simulations of the failure of cohesive granular steps with varying intensities of the contact adhesive force are presented. The simulations are compared with experimental and numerical studies of wet shear flows [Badetti et al., J. Rheol. 62, 1175–1196 (2018) and Khamseh et al., Phys. Rev. E 92, 022201 (2015)], computing the apparent friction coefficient. We observe consistent behaviors. We reproduce the dependence between the macroscopic cohesion and the contact adhesion [Rumpf, Chem. Ing. Tech. 42, 538–540 (1970) and Richefeu et al., Phys. Rev. E 73(5), 051304 (2006)] observed experimentally for sticky polymer-coated grains, as well as the range of friction explored [Gans et al., Phys. Rev. E 101, 032904 (2020)]. Focusing on the interface between moving and static materials, and assuming a linear failure, we infer the orientation of the failure plane with the horizontal. We disclose a nonmonotonous evolution with the intensity of the contact adhesion. Assuming an ideal Coulomb material allows for proposing an interpretation to this nonmonotonous behavior. Although the systems are past incipient failure, we consider an edge of material at equilibrium, for which the failure angle is related to the internal frictional properties of the material. In this framework, the nonmonotonous evolution of the failure orientation may hint at a cohesion-induced weakening mechanism, by which stronger contact adhesion involve weaker friction.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46721219","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}

{"title":"Interfacial shear rheology of glassy polymers at liquid interfaces","authors":"Stelios Alexandris, Daniel Ashkenazi, J. Vermant, D. Vlassopoulos, M. Gottlieb","doi":"10.1122/8.0000685","DOIUrl":"https://doi.org/10.1122/8.0000685","url":null,"abstract":"When surface-active molecules or particles assemble at fluid–fluid interfaces, these interfaces acquire complex rheological properties that are of importance in processes that involve flow and deformation of interfaces. Although much progress has been made, interfacial rheology measurements and, in particular, the measurement of interfacial rheological properties of polymers at the air-water interface remain challenging. These are due to weak interactions with the water subphase, the polymer backbone conformation, the glass transition of the interfacial layer, and memory effects. In the present work, we describe systematic rheological measurements of polymer-laden interfaces. The measurements were performed with four different interfacial shear rheometers that can be classified into two types: rheometers in which the surface pressure can be controlled independently, and devices based on fixtures mounted on standard rotational rheometers and lacking control of the surface pressure. We use poly(tert-butyl methacrylate) and poly(methyl methacrylate), two high glass transition temperature, hydrophobic polymers anchored to the water subphase by means of the acrylate group. Using a Langmuir–Pockels (LP) trough, we identify the transition of the polymer monolayer from a viscous to a solid elastic or soft-glassy interface as the polymer surface concentration increases by compression. Then, we compare the linear viscoelastic properties of the interface as obtained by each rheometer. Our results show poor reproducibility and comparability of the rheological data as obtained by different rheometers for the same polymer. This is mainly due to differences in the method used to prepare the layers. For LP-based devices, spreading under dilute conditions and subsequent compression yields layers of compressed glassy blobs with reproducible results. On the other hand, for devices without surface pressure control, deposition of the amount needed to reach a desired concentration may lead to the formation of ill-defined layers resulting in irreproducible data. Furthermore, we find that only when spreading the polymer to form a dilute layer and then controlling the surface pressure by compression, we can clearly distinguish the fluidlike from solidlike interfaces, and a clear correlation is observed between the surface pressure (or interfacial polymer concentration) and the rheological properties of the interface.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44371435","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}

{"title":"Z-shaped dejamming phase diagram of colloidal gels","authors":"B. Xia, Shoubo Li, Xiaorong Wang","doi":"10.1122/8.0000666","DOIUrl":"https://doi.org/10.1122/8.0000666","url":null,"abstract":"For physically gelled colloidal suspensions, there are two routes to transform the gel from solid to liquid. One is to raise the temperature, and the other is to increase the shear deformation. In this investigation, we found that the phase boundary of this solid-to-liquid transformation exhibits a surprising Z-shaped curve in the strain-temperature plane. This nonmonotonic feature in phase transition appears to be present in various nanoparticle-filled colloidal gels with significant differences in chemical composition, filler type, structure, particle shape, average diameter, and particle size distribution. By applying the Kraus model to the breakage and restoration of filler networks and comparing our findings to nonequilibrium glassy behavior, we found that this nonmonotonic phenomenon can be theoretically predicted by combining the glassy melting kinetics of filler networks at high temperatures with the viscosity-retarded dissociation between particles at low temperatures.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48166848","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}

{"title":"Effect of steady shear deformation on electrically conductive PP/PS/MWCNT composites","authors":"D. Strugova, É. David, N. Demarquette","doi":"10.1122/8.0000647","DOIUrl":"https://doi.org/10.1122/8.0000647","url":null,"abstract":"Conductive polymeric materials are commonly obtained by adding conductive nanoparticles to blends of immiscible polymers that form a cocontinuous morphology. However, during processing, morphology changes, affecting material properties. This study investigates the impact of steady shear deformation on the morphological and electrical properties of a model system consisting of polypropylene/polystyrene/multiwall carbon nanotubes (MWCNTs). The findings reveal that the deformation results in the coarsening of the blend morphology and disruption of the electrical network, increasing both the rheological and electrical percolation threshold concentrations. The evolution of both electrical and morphological properties depends on MWCNT concentration, strain amplitude, and shear rate. The MWCNT concentration, below a certain level, leads to a disruption in electrical conductivity at high shear rates. However, if the MWCNT concentration is above 1 wt. %, the balance between filler network breakup and nanoparticle diffusion is maintained, resulting in stable electrical conductivity and morphology.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45815368","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}

{"title":"A computer program for interconversion between creep compliance and stress relaxation","authors":"S. Shanbhag","doi":"10.1122/8.0000695","DOIUrl":"https://doi.org/10.1122/8.0000695","url":null,"abstract":"Numerical interconversion of linear viscoelastic functions is an important problem in rheology. This work focuses on interconversion between creep compliance (J) and relaxation modulus (G) via the convolution relation. A discrete spectrum or Prony series is used to describe both the source (G or J) and the target (J or G) of the interconversion. A previously developed numerical template [Loy et al.,J. Rheol.59(5), 1261 (2015)] is modified to bypass singularities. It is released as an open-source computer program called PSI (Prony series interconversion). PSI is tested on a variety of materials including viscoelastic solids and liquids and used for both G→J and J→G interconversions. It is fast and numerically stable for input data that span over 20 decades in time. It fills a gap in the existing software landscape for conversion of linear viscoelastic functions.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48091555","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}

{"title":"Perspective on edge fracture","authors":"S. T. Chan, S. Varchanis, S. Haward, A. Shen","doi":"10.1122/8.0000625","DOIUrl":"https://doi.org/10.1122/8.0000625","url":null,"abstract":"Edge fracture is a viscoelastic instability characterized by the sudden indentation of a fluid’s free surface when the fluid is subjected to a high enough shear rate. During shear rheometry, the fracture can invade the fluid sample, decreasing its contact area with the rheometer fixture and rendering the measurement of viscosity and normal stresses at high-shear rates invalid. Edge fracture can also induce apparent shear banding in the fluid, complicating the interpretation of experimental results. Over the past several decades, empirical and theoretical research has unraveled the physics underlying edge fracture. The knowledge obtained has allowed rheologists to develop techniques to minimize the adverse effect of fracture in their experiments. In recent years, edge fracture has also been used to break up viscoelastic liquid bridges quickly and cleanly, showing its potential to be adapted to the design of functional dispensing nozzles. This Perspective article aims to give a historical overview of edge fracture and suggests research directions to develop methods for suppressing or harnessing the phenomenon to benefit applications of both fundamental and technological importance.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48770929","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}

{"title":"Understanding the reactive interfacial flow dynamics with production of viscoelastic material through large amplitude oscillatory shear (LAOS) measurements of the viscoelastic interface","authors":"Harumi Yagi, Y. Nagatsu, Masayoshi Takano, Ryuta X. Suzuki","doi":"10.1122/8.0000650","DOIUrl":"https://doi.org/10.1122/8.0000650","url":null,"abstract":"In this study, the interfacial flow dynamics involving a chemical reaction that produces viscoelastic material at the interface between two liquids is experimentally investigated, and the material is evaluated using interfacial large amplitude oscillatory shear (LAOS) measurements. The flow dynamics indicates fingering patterns at low injection flow rates and fracturing patterns at high flow rates in Hele-Shaw cells, where a more viscous xanthan gum solution is displaced by the less viscous Fe(NO3)3 solution with various concentrations of Fe(NO3)3. The threshold flow rate value of such a transition is different for various concentrations of Fe(NO3)3. Although such a transition without chemical reactions has been discussed, the factors responsible for the transition remain unclear. The flow dynamics in Hele-Shaw cells is considered to flow under large deformation, which exceeds the small amplitude oscillatory shear condition but is under the LAOS condition. Therefore, LAOS measurement of the viscoelastic interface is performed for various concentrations of Fe(NO3)3. Using the characteristic properties extracted from the LAOS measurements, the elastic and viscous forces of the viscoelastic interface are evaluated. We show the transition from fingering to fracturing patterns when the elastic force exceeds a certain value. These findings highlight that rheology under large deformation of the viscoelastic interface plays a crucial role in interfacial flow, where viscoelastic materials are produced by chemical reactions at the interface. In addition, this study should be an example of the successful elucidation of physical phenomena by interfacial LAOS, which has been reported in a very limited number of studies.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43189442","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}

{"title":"A novel and noninvasive approach to study the shear rheology of complex fluid interfaces","authors":"D. Venerus","doi":"10.1122/8.0000649","DOIUrl":"https://doi.org/10.1122/8.0000649","url":null,"abstract":"Surfactants at gas-liquid and liquid-liquid interfaces have profound effects on interfacial stresses that strongly influence flow in bulk phases in contact with the interface. These effects include changes in interfacial tension and the development of extra stresses that arise when the interface is deformed. Surfactants are important in nature, biological function, and numerous technologies. Understanding interfacial rheology is critical to the development of improved surfactants for these important applications. Here, we propose a novel and noninvasive technique for the investigation of interfacial rheological behavior in shear deformations. In recent years, several techniques for such measurements have been developed and utilized to study a wide range of surfactant systems. However, existing techniques may inherently be invasive making it difficult to isolate the intrinsic interfacial rheological behavior from disturbances to the interface caused by the measurement itself. The proposed technique is indirect in that it does not require the introduction of a probe to deform the interface making it noninvasive. The viability of the technique is demonstrated through comprehensive fluid dynamics modeling of the flow involving a gas-liquid interface with different rheological behaviors.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49572827","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}

{"title":"Cohesion and aggregates in unsaturated wet granular flows down a rough incline","authors":"S. Deboeuf, A. Fall","doi":"10.1122/8.0000631","DOIUrl":"https://doi.org/10.1122/8.0000631","url":null,"abstract":"Multi-phase flows, encountered in nature or in industry, exhibit non-trivial rheological properties, which we attempt to better understand thanks to model materials and appropriate rheometers. Unsaturated wet granular flows down a rough inclined plane turn out to be steady and uniform for a wide range of parameters, despite the cohesion and the grain aggregates. The cohesive Mohr–Coulomb yield criterion extended to inertial granular flows, with a cohesion stress dependent on the liquid content and an internal friction coefficient dependent on the inertial number, allows for predictions in good agreement with our experimental measurements, when one introduces a grain aggregate size, which defines the appropriate length and relaxation time scales in the inertial number. We found that the grain aggregate size depends not monotonically on the liquid content and does not scale with the cohesion length induced by the cohesion stress, due to the non-trivial distribution of the liquid within the granular material.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45472537","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}

{"title":"Rheo-PIV of yield-stress fluids in a 3D-printed fractal vane-in-cup geometry","authors":"Esteban F. Medina-Bañuelos, B. M. Marín-Santibáñez, E. Chaparian, C. Owens, G. McKinley, J. Pérez-González","doi":"10.1122/8.0000639","DOIUrl":"https://doi.org/10.1122/8.0000639","url":null,"abstract":"The vane-in-cup (VIC) geometry has been widely used for the rheological characterization of yield-stress fluids because it minimizes slip effects at the liquid/solid interface of the rotating geometry and reduces sample damage during the loading process. However, severe kinematic limitations arising from the spatial complexity of mixed shear and extensional flow have been identified for quantitative rheometrical measurements in complex fluids. Recently, vanes with fractal cross sections have been suggested as alternatives for accurate rheometry of elastoviscoplastic fluids. In this work, the steady fractal vane-in-cup (fVIC) flow of a Newtonian fluid and a nonthixotropic Carbopol® 940 microgel as well as the unsteady flow of a thixotropic κ-Carrageenan gel are analyzed using rheo-particle image velocimetry (Rheo-PIV). We describe the velocity distributions in all cases and show that the fVIC produces an almost axisymmetric flow field and rotation rate-independent “effective radius” when used with both the Newtonian fluid and the microgel. These findings are supported by 2D simulation results and enable the safe use of both the Couette analogy and the torque-to-stress conversion scheme for a 24-arm fVIC as well as validate it as a reliable rheometrical tool for characterization of a variety of complex fluids. With the κ-Carrageenan gel, however, axial shearing/compression while inserting the rheometric tool into the sample also accelerates syneresis that ultimately results in shear banding for Couette and fVIC flows. By comparing results obtained using the 24-arm fVIC with other conventional geometries, we investigate the effect that the lateral and cross-sectional (shearing/compressing) area of the measuring fixture have on disrupting the κ-Carrageenan gel during its insertion.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45025603","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}