Rheologica Acta最新文献

{"title":"Path-independent flow characterization of model yielding pastes","authors":"Gavin J. Donley,&nbsp;Nicos Martys,&nbsp;Emanuela Del Gado,&nbsp;Kenneth Snyder","doi":"10.1007/s00397-026-01553-y","DOIUrl":"10.1007/s00397-026-01553-y","url":null,"abstract":"<div>\u0000 \u0000 <p>Yielding pastes are a class of soft materials that have the ability to mechanically transition between solid-like deformation and fluid-like flow based on the level of mechanical loading. This phenomenology, particularly when it is reversible, makes them ideal for use in additive manufacturing processes such as direct-ink-writing (DIW) 3D printing. To optimize materials for such applications, robust characterization of the flow behavior of these materials is needed. The most common means of doing this is the collection of a steady-shear flow curve, which consists of a series of constant shear rate tests across the desired deformation range, tracking the stress required for the deformation in each. The exact means by which this is accomplished, however, varies quite widely, with literature implementing tests with a variety of collection orders, preshear protocols, and end-of-test conditions. As many yielding pastes exhibit complex shear history, this variation in testing procedures creates a potential obstacle for obtaining reproducible results. To address this, we compare the flow curves of model yielding pastes as the order of measurements is changed. We also examine the impact of material conditioning on these changes by contrasting between a conventional shear-ramping preconditioning and a novel oscillatory/forced-recovery preshear. By examining the effect that the measurement collection order has on collected flow curves of multiple model yielding pastes, we determine the inclusion of an oscillatory preshear containing a forced-recovery step in-between successive measurements allows for a minimization of the path-dependence caused by material shear history.</p>\u0000 </div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 4","pages":"341 - 352"},"PeriodicalIF":3.0,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147588370","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}

{"title":"Selected contributions from the Canadian Society of Rheology Symposium, Montreal 2025","authors":"Giovanniantonio Natale,&nbsp;Nicole R. Demarquette","doi":"10.1007/s00397-026-01554-x","DOIUrl":"10.1007/s00397-026-01554-x","url":null,"abstract":"","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 3","pages":"207 - 207"},"PeriodicalIF":3.0,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147558968","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}

{"title":"Study on creep behavior and constitutive model of salt rock based on the spatiotemporal evolution mechanism of structure","authors":"Lele Lu,&nbsp;Haiyang Yi,&nbsp;Zhide Wu,&nbsp;Tingjin Liu,&nbsp;Mingwu Liu,&nbsp;Bingbing Liu,&nbsp;Dongjie Xue,&nbsp;Shiping Huang","doi":"10.1007/s00397-026-01549-8","DOIUrl":"10.1007/s00397-026-01549-8","url":null,"abstract":"<div><p>Under complex stress conditions, the spatiotemporal coupling between creep deformation and structural degradation of salt rock remains unclear. Traditional creep models mainly rely on macroscopic strain fitting, neglecting the intrinsic correlation between micro-damage and macroscopic structural evolution, which leads to ambiguous physical meanings, redundant parameters, and limited predictive capability. In this study, the microstructural evolution, acoustic emission response, and strain characteristics of salt rock during creep were analyzed to reveal the staged deformation mechanisms: in the initial stage, pores and microcracks gradually close; in the steady stage, microcracks independently nucleate and slowly propagate, marking the onset of new damage; and in the accelerated stage, deformation shifts from viscoelastic to instantaneous plastic compression. Accordingly, the total creep strain is decomposed into elastic, viscoelastic, and plastic compression components. Based on the fractional derivative Maxwell model, a nonlinear creep model incorporating a damage-attenuated Hookean element and a switch element was established to describe structural degradation and plastic compression. Creep tests on different types of salt rocks under various stress paths verified the model’s capability through staged parameter identification. A parameter sensitivity analysis was conducted for the plastic compressive strain model, further enhancing the convenience of model application. Based on the composition of creep strain, the strain evolution patterns of different types of salt rock under multiple stress levels were systematically analyzed, providing theoretical support for the precise characterization of time-dependent deformation and instability prediction of surrounding rocks in deep salt cavern reservoirs.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 4","pages":"369 - 388"},"PeriodicalIF":3.0,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147588471","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}

{"title":"Correction to: Shear jamming and nonlinear rheology of chocolate suspensions","authors":"Michel Orsi,&nbsp;Veeraj Shah,&nbsp;Mahesh Padmanabhan,&nbsp;Thomas Curwen,&nbsp;Jeffrey F. Morris","doi":"10.1007/s00397-026-01552-z","DOIUrl":"10.1007/s00397-026-01552-z","url":null,"abstract":"","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 2","pages":"205 - 206"},"PeriodicalIF":3.0,"publicationDate":"2026-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147579318","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}

{"title":"Rheology of fiber–reinforced xanthan gum solutions","authors":"Mohsen Faramarzi,&nbsp;Seyed Mohammad Taghavi","doi":"10.1007/s00397-025-01544-5","DOIUrl":"10.1007/s00397-025-01544-5","url":null,"abstract":"<div><p>We investigate the rheology of synthetic organic fiber–reinforced xanthan gum solutions, via varying fiber concentration (0–4 g/L), length (1.8–12 mm), and temperature (10–50<span>(^circ)</span>C). Steady shear sweeps, oscillatory amplitude sweeps, and creep tests are performed. Three regimes are identified: (i) weak-interaction, where short fibers or low concentrations have little effect; (ii) shear-responsive networks, where intermediate fibers form weak structures at low shear that collapse under higher shear; and (iii) network-dominated, where higher concentrations and longer fibers increase viscosity across all shear rates and intensify non-Newtonian behavior. Oscillatory and creep tests confirm progressive network formation, increased elasticity, higher storage modulus, and elevated crossover stresses. Creep data show a transition from fluid-like to bounded, solid-like deformation. Temperature induces thinning, partly offset at higher loadings, while longer fibers raise yield stress and consistency, especially at high concentrations.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 3","pages":"241 - 254"},"PeriodicalIF":3.0,"publicationDate":"2026-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560488","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}

{"title":"Slip flows of a Bingham fluid in curved channels","authors":"Simon Cox,&nbsp;Seyed Mohammad Taghavi","doi":"10.1007/s00397-026-01548-9","DOIUrl":"10.1007/s00397-026-01548-9","url":null,"abstract":"<div><p>Motivated by the treatment of varicose veins with aqueous foams, we determine the velocity profiles and yield surface positions for pressure-driven flows of a Bingham fluid in curved channels, incorporating Navier wall slip to capture the slip behavior of aqueous foams. Assuming a constant pressure gradient – consistent with syringe-driven injection in sclerotherapy – we reproduce a closed-form analytic solution for the flow in a straight channel, and extend this to a uniformly curved channel consisting of a section of an annulus. We find that increasing the slip length in the curved channel moves the unyielded fluid, or plug, towards the inside of the channel and slightly decreases the plug width. Channels with a change in curvature are tackled numerically, with a procedure that is validated against the analytic results. We solve for the flow of a Bingham fluid in the transition region between a straight and a uniformly curved channel and in a non-uniform sinusoidal channel where the wall curvature changes continuously. We find that there is greater yielding of the fluid in curved channels, caused by an increase in the shear stresses. As the slip length increases, there is a reduction in the area of unyielded fluid in regions of high wall curvature. In the context of varicose vein sclerotherapy, our results suggest that slip has both positive and negative consequences: it eliminates the possibility of static regions of foam developing in areas of high curvature in the vein, but also reduces the plug width in general, affecting the efficacy with which the foam displaces blood from the vein.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 4","pages":"353 - 367"},"PeriodicalIF":3.0,"publicationDate":"2026-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-026-01548-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147588391","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}

{"title":"Multilayer nanofilled polymer systems under extensional flow: Role of filler aspect ratio and interfacial chain dynamics","authors":"Jixiang Li,&nbsp;Emna Masghouni,&nbsp;Guillaume Sudre,&nbsp;Abderrahim Maazouz,&nbsp;Khalid Lamnawar","doi":"10.1007/s00397-026-01547-w","DOIUrl":"10.1007/s00397-026-01547-w","url":null,"abstract":"<div><p>The influence of carbon nanofillers on the melt extensional behavior of multilayer polymer nanocomposites was investigated using linear low-density polyethylene (LLDPE) as matrices embedded with either carbon nanostructures (CNS) or multi-walled carbon nanotubes (MWCNTs). Multilayer films with controlled layer architectures were fabricated via forced-assembly co-extrusion. Extensional rheology tests revealed that CNS, due to their higher aspect ratio and stronger interfacial interactions with LLDPE chains, significantly enhanced the extensional viscosity and strain hardening behavior, especially in highly layered (1025L) systems. By contrast, MWCNT-filled films exhibited extensional responses similar to the neat LLDPE matrix, indicating minimal nanofiller–polymer interaction. Microstructural analyses via SEM, TEM, and SAXS confirmed the alignment of CNS under extension and the presence of thick interfacial bound polymer layers, leading to complex interfacial chain relaxation dynamics. Furthermore, stress yielding observed in CNS-filled systems with fewer layers (e.g., 9L) was attributed to structural instabilities and filler-rich layer breakup. These findings provide new insights into the role of nanofiller morphology and interfacial dynamics in tuning extensional rheology, with implications for advanced polymer processing and modeling of nanocomposite systems.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 2","pages":"167 - 183"},"PeriodicalIF":3.0,"publicationDate":"2026-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147579525","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}

{"title":"Melt strain hardening of polypropylenes and its relation to molecular structure: a review","authors":"Helmut Münstedt","doi":"10.1007/s00397-025-01543-6","DOIUrl":"10.1007/s00397-025-01543-6","url":null,"abstract":"<div><p>Strain hardening of polymer melts is a rheological feature that improves properties of items processed by operations with pronounced extensional deformations. Thus, developments have been undertaken over the years to modify linear polypropylenes not showing strain hardening. The different ways to generate strain hardening polypropylenes are reviewed, and it is shown how rheological relations can be used for their characterization. Chemical reactions are shortly addressed, but the main focus lies on the generation of long-chain branches by electron-beams or γ-irradiation. Blends of a commercial long-chain branched and a linear isotactic polypropylene exhibit strain hardening and branching features determined in the highly diluted state by usual techniques that are comparable to the electron-beam irradiated samples. But measurements of the zero-shear viscosity as a function of molar mass provide a hint to different branching structures: Tree-like components for the blends and star-like molecules for the weakly electron-beam irradiated species. Using the results of these rheological methods, the influence of various experimental parameters like type of irradiation source and irradiation dose or temperature and molar mass of the irradiated polypropylene on the branching structures is elucidated. Furthermore, the different dependencies of strain hardening on elongation rate for samples with various branching structures are discussed, and a qualitative interpretation is presented.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><img></picture></div></div></figure></div></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 2","pages":"93 - 111"},"PeriodicalIF":3.0,"publicationDate":"2026-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-025-01543-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147579405","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}

{"title":"The modified Rouse model incorporating supplementary effects: I. Nonlinear modification for chain volume conservation and anisotropic friction","authors":"Youngdon Kwon","doi":"10.1007/s00397-026-01545-y","DOIUrl":"10.1007/s00397-026-01545-y","url":null,"abstract":"<div>\u0000 \u0000 <p>This study reexamines the constraint for volume conservation of the Rouse chain proposed recently (Kwon 2024). We provide conceivable reasoning for the constraint written in terms of the normal mode amplitude. Formulating the necessary number of constraints is verified to require vanishing correlation between distinct linear combinations of segmental vectors. Considering these observations, we prove that the normal mode amplitude is the only choice appropriate for the constraint. The constitutive equation derived expresses shear thinning with the exponent in the range between <span>(:-0.4)</span> and <span>(:-0.6)</span>, and therefore approximately matches the experiments. Second, we investigate the anisotropic friction. The anisotropy is modeled by substituting the friction tensor. We decompose the inverse of the friction tensor into reduced, isotropic and accreted friction terms. This implementation enables modeling finite value of <i>N</i>₂ as well as friction reduction. Probable correlation between <i>N</i>₂ and the extensional friction reduction has been also demonstrated.</p>\u0000 </div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 2","pages":"153 - 166"},"PeriodicalIF":3.0,"publicationDate":"2026-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-026-01545-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147579235","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}

{"title":"Solvent evaporation induces stiffening in caber and electrospinning of volatile polymer solutions","authors":"Étienne J. Beaudoin,&nbsp;Ricardo J. Zednik,&nbsp;Nicole R. Demarquette","doi":"10.1007/s00397-026-01550-1","DOIUrl":"10.1007/s00397-026-01550-1","url":null,"abstract":"<div>\u0000 \u0000 <p>Nanoscale polymer fibers have gained increasing attention over the past two decades due to their applications in filtration, sensing, and biomedical devices. These fibers are commonly produced by electrospinning, where a polymer solution is stretched in extension and rapidly solidifies through solvent evaporation. Since flow behavior plays a key role in determining fiber morphology, extensional rheology techniques such as Capillary Breakup Extensional Rheometry (CaBER) are often used to characterize polymer solutions. Like electrospinning, CaBER involves the formation and thinning of a filament exposed to ambient air. In this study, the influence of solvent evaporation on both electrospinning and CaBER measurements is investigated under controlled ambient vapor pressures (25% to 90%) using aqueous pullulan solutions. Electrospinning results show that lower vapor pressure accelerates solvent evaporation, leading to early jet solidification and the formation of thicker fibers. In parallel, CaBER measurements reveal longer relaxation times at low vapor pressure, suggesting evaporation-induced stiffening. To better understand this effect, a model was developed to calculate solvent evaporation at the filament surface and the resulting radial redistribution of solvent within the filament by diffusion. Using experimental filament radius data as input, the polymer concentration profile across the filament cross-section was computed over time. From these local concentration fields, the corresponding apparent bulk viscosity was calculated using a concentration-dependent viscosity relationship. Simulation results show that at low vapor pressure, polymer concentration increases near the surface due to solvent loss, which in turn leads to a significant rise in the apparent viscosity as the filament thins. The convergence of results from electrospinning, CaBER, and modeling highlights the strong influence of solvent evaporation on extensional flow behavior. These findings emphasize the need for careful environmental control and evaporation-aware modeling when characterizing volatile polymer solutions.</p>\u0000 <span>AbstractSection</span>\u0000 Graphical abstract\u0000 <div><figure><div><div><picture><source><img></source></picture></div></div></figure></div>\u0000 \u0000 </div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 4","pages":"303 - 315"},"PeriodicalIF":3.0,"publicationDate":"2026-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147588546","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}