Rheologica Acta最新文献_第8页

Contact distribution–based prediction of yield stress in magnetorheological fluids 基于接触分布的磁流变流体屈服应力预测

IF 3 3区工程技术

Rheologica Acta Pub Date : 2025-11-14 DOI: 10.1007/s00397-025-01527-6

Manuel J. Espín

{"title":"Contact distribution–based prediction of yield stress in magnetorheological fluids","authors":"Manuel J. Espín","doi":"10.1007/s00397-025-01527-6","DOIUrl":"10.1007/s00397-025-01527-6","url":null,"abstract":"<div><p>Magnetorheological (MR) fluids exhibit field-dependent rheological behavior arising from the reversible formation of particle chains under applied magnetic fields. Predicting the static yield stress of these systems remains a central challenge in their modeling and design. This work presents a closed-form analytical expression for the yield stress of MR fluids, derived from a particle-scale formulation that incorporates multipolar magnetic interactions and microstructural descriptors. The model explicitly accounts for the average number of interparticle contacts and the inclination angle of the chains relative to the internal magnetic field within the suspension, based on a simple microstructural hypothesis involving chain-like aggregates. A mechanical stability criterion is also formulated by identifying a critical inclination angle, <span>(theta _{textrm{c}})</span>, below which chains remain stable under the combined influence of magnetic attraction and hydrodynamic shear. This condition is obtained from force and torque balance at the chain–particle level and is applicable over a wide range of experimental conditions. Model validation is performed through complementary comparisons: the yield stress predicted by the model is directly contrasted with experimental data, while the corresponding chain inclination angles reconstructed from these measurements are compared with theoretical predictions of <span>(theta _{textrm{c}})</span>. The results show that the formulation captures observed trends and outperforms classical dipolar approaches across diverse particle sizes, magnetic properties, and field strengths, with confirmed applicability up to <span>(phi lesssim 0.20)</span>. Additionally, an analysis of competing interparticle forces reinforces the assumptions underlying the model and its domain of applicability.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 1","pages":"65 - 91"},"PeriodicalIF":3.0,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146027150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Quick starch guide: a perspective on shear thickening in dense non-Brownian suspensions 快速淀粉指南：致密非布朗悬浮液剪切增稠的观点

IF 3 3区工程技术

Rheologica Acta Pub Date : 2025-11-01 DOI: 10.1007/s00397-025-01519-6

Cécile Clavaud, Abhinendra Singh

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SAOS and LAOS rheology for differentiating chemical and physical crosslinking: A case study on PVA hydrogels 用于区分化学和物理交联的SAOS和LAOS流变学：以PVA水凝胶为例研究

IF 3 3区工程技术

Rheologica Acta Pub Date : 2025-10-21 DOI: 10.1007/s00397-025-01522-x

David Kogan, Moshe Gottlieb

{"title":"SAOS and LAOS rheology for differentiating chemical and physical crosslinking: A case study on PVA hydrogels","authors":"David Kogan, Moshe Gottlieb","doi":"10.1007/s00397-025-01522-x","DOIUrl":"10.1007/s00397-025-01522-x","url":null,"abstract":"<div><p>In this work, we have studied the viscoelastic behavior of chemically and physically crosslinked Poly(vinyl alcohol) (PVA) hydrogels near the critical gel point (GP) as well as further away from it, by means of small amplitude (SAOS) and large amplitude (LAOS) oscillatory shear experiments. Chemical crosslinking involved covalent bonding by means of glutaraldehyde as a crosslinker, while physical crosslinking was induced by freeze–thaw cycles. SAOS data analysis allowed evaluation of critical parameters such as the critical relaxation exponent <i>n</i>, gel strength <i>S</i>, and equilibrium modulus <i>Ge</i>, based on the dynamic self-similarity and fractal network structures at the GP. LAOS rheological data analysis showed that the chemically crosslinked system exhibited moderate strain-dependance due to the permanent covalent bonds, whereas the physically crosslinked system displayed significant strain-dependent nonlinearity due to strain dependent interactions at the crosslink entities. LAOS experiments, supported by Chebyshev coefficients and Lissajous-Bowditch plots, highlighted pronounced differences in nonlinear responses, underscoring the influence of crosslinking mechanisms on the network rheological behavior. The findings establish LAOS as a powerful tool for differentiating polymeric network structures, providing insights beyond those attained by conventional linear rheology.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"64 11","pages":"601 - 620"},"PeriodicalIF":3.0,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-025-01522-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145511101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Identifying the chemical gel point of epoxy-fumed silica composites using optimally windowed chirp measurements 确定化学凝胶点环氧气相硅复合材料使用最佳窗口啁啾测量

IF 3 3区工程技术

Rheologica Acta Pub Date : 2025-10-15 DOI: 10.1007/s00397-025-01526-7

Stian K. Romberg, Sarah Lehrman, Jonathan E. Seppala, Anthony P. Kotula

{"title":"Identifying the chemical gel point of epoxy-fumed silica composites using optimally windowed chirp measurements","authors":"Stian K. Romberg, Sarah Lehrman, Jonathan E. Seppala, Anthony P. Kotula","doi":"10.1007/s00397-025-01526-7","DOIUrl":"10.1007/s00397-025-01526-7","url":null,"abstract":"<div><p>The chemical gel point that occurs in the resin matrix of thermoset composites is crucial to the design of manufacturing process parameters. However, the formation of a physical network of filler material can affect the viscoelastic response of the composite so strongly that conventional rheological indicators of the chemical gel point (like power-law stress relaxation) are no longer observed. Additionally, many industrially relevant thermoset composites have a small linear viscoelastic region, limiting the utility of the high-strain multiwave measurement approach that was developed to monitor the frequency-dependent behavior of rapidly evolving materials. Here, we pair frequency-dependent properties obtained by low-strain Optimally Windowed Chirp (OWCh) measurements with existing rheology-conversion relationships to apply time-cure superposition to the loss tangent of epoxy-amine resins filled with unreactive particles. We show that this advanced rheological approach allows us to track the relative change in the relaxation time, providing another way to identify the elusive chemical gel point of these thermoset composites. The results allow us to assess the applicability of several gel point criteria to crosslinking composites, including the <i>G'</i>-<i>G''</i> crossover, frequency-independent tan <i>δ</i>, peak in tan <i>δ</i>, and divergence of the relaxation time. Investigation of a resin with a weak filler network reveals all of these gel point criteria, with the frequency-independent tan <i>δ</i> providing the best agreement with the easily identifiable gel point of the neat resin. For resins with a strong physical filler network, frequency independence of tan <i>δ</i> does not occur, but the divergence of the relaxation time matches the gel point of the neat resin and the peak in tan <i>δ</i>.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"64 11","pages":"673 - 685"},"PeriodicalIF":3.0,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145511094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Correction to: Second normal stress difference measurement via interfacial deformation of stratified flow into a closed-channel 修正：通过分层流进入封闭通道的界面变形进行的第二次正应力差测量

IF 3 3区工程技术

Rheologica Acta Pub Date : 2025-10-01 DOI: 10.1007/s00397-025-01525-8

Luca Passaro, Eugene Pashkovski, Christian Clasen

引用次数: 0

Yielding of model particle-laden interfaces in shear and compression 模型颗粒加载界面在剪切和压缩下的屈服

IF 3 3区工程技术

Rheologica Acta Pub Date : 2025-10-01 DOI: 10.1007/s00397-025-01524-9

Alexandra Alicke, Jan Vermant

{"title":"Yielding of model particle-laden interfaces in shear and compression","authors":"Alexandra Alicke, Jan Vermant","doi":"10.1007/s00397-025-01524-9","DOIUrl":"10.1007/s00397-025-01524-9","url":null,"abstract":"<div><p>Particle-laden interfaces have been extensively used due to their excellent capabilities of imparting stability in multiphase materials in what is called Pickering-Ramsden stability. While particles are usually added in amounts that create maximally packed or multilayer coverages on a bubble or droplet interface, it has been reported that even sub-monolayer coverages can impart a finite interfacial yield stress—already strong enough to arrest bubble dissolution. In the present work, we use a model elastoviscoplastic interface and custom-built interfacial rheometry set-ups to interrogate the yielding behavior in both shear and compressional/dilatational deformation modes while simultaneously looking at the 2D microstructure. Depending on surface coverage, either flocculated networks or densely packed particle-laden interfaces are obtained. We specifically investigate the transition from linear to nonlinear behavior in different rheometric experiments and relate the transitions, from elastic to plastic to viscous deformations, to microstructural observations. With full microstructural resolution in two-dimensional systems being easily accessible, the results inform both the deliberate tuning of interfacial mechanics and provide insights into the fundamental mechanisms governing yield in bulk materials.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"64 9-10","pages":"583 - 600"},"PeriodicalIF":3.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-025-01524-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145479655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A two-axes shear cell for rheo-optics 一种用于流变光学的两轴剪切单元

IF 3 3区工程技术

Rheologica Acta Pub Date : 2025-09-30 DOI: 10.1007/s00397-025-01520-z

Marraffa Chiara, Aime Stefano

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A double exponential chirp waveform for noisy rheology 噪声流变学的双指数啁啾波形

IF 3 3区工程技术

Rheologica Acta Pub Date : 2025-09-23 DOI: 10.1007/s00397-025-01514-x

Jarno L. Waeterloos, Gareth H. McKinley, Christian Clasen

{"title":"A double exponential chirp waveform for noisy rheology","authors":"Jarno L. Waeterloos, Gareth H. McKinley, Christian Clasen","doi":"10.1007/s00397-025-01514-x","DOIUrl":"10.1007/s00397-025-01514-x","url":null,"abstract":"<div><p>In the search for faster rheometrical measurements techniques for fast time-evolving systems, optimally windowed chirps (OWCh) have recently been proposed for the determination of the complex modulus. However, such chirps are prone to artefacts at high frequencies due to fact that the input power is distributed over a range of frequencies leading to reduced signal-to-noise ratios in noisy conditions. The Tukey window which modulates the amplitude of the excitation disturbance and which is required to avoid spectral leakage directly reduces the signal-to-noise ratio at the edges of the signal leading to a divergence of the measured moduli at high frequencies. A new double exponential chirp (DEC) signal is proposed to overcome these limitations. Its capabilities are demonstrated with orthogonal superposition rheometry as an example of a demanding high-noise environment. The S-shaped time-frequency history of the new chirp signal redistributes the input power over the frequency spectrum. Numerical simulations using the Maxwell and Giesekus models, along with orthogonal superposition measurements on wormlike micellar fluids, demonstrate the effectiveness of the DEC waveform. Parameter optimization with the Giesekus model identifies the ideal input configurations for achieving a maximum signal-to-noise ratio during rheological measurements.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"64 11","pages":"633 - 646"},"PeriodicalIF":3.0,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145510949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Special issue devoted to early-career researchers and novel trends in rheology 特刊致力于早期职业研究人员和流变学的新趋势

IF 3 3区工程技术

Rheologica Acta Pub Date : 2025-09-18 DOI: 10.1007/s00397-025-01523-w

Giovanni Ianniruberto, Simon A. Rogers

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Second normal stress difference measurement via interfacial deformation of stratified flow into a closed-channel 第二次利用层状流进入封闭通道的界面变形测量法向应力差

IF 3 3区工程技术

Rheologica Acta Pub Date : 2025-09-11 DOI: 10.1007/s00397-025-01521-y

Luca Passaro, Eugene Pashkovski, Christian Clasen

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