Rheologica Acta最新文献

{"title":"Viscoelastic alterations of human semen associated with diagnosed male infertility","authors":"Eleonora Pero,&nbsp;Giovanna Tomaiuolo,&nbsp;Federica Cariati,&nbsp;Valentina Preziosi,&nbsp;Antonella Panarelli,&nbsp;Ida Strina,&nbsp;Carlo Alviggi,&nbsp;Stefano Guido","doi":"10.1007/s00397-026-01569-4","DOIUrl":"10.1007/s00397-026-01569-4","url":null,"abstract":"<div><p>Human semen is a complex biological fluid whose rheological properties are relevant to male fertility and assisted reproductive technologies. Standard clinical assessment is largely qualitative and operator dependent, motivating the search for objective biophysical markers of semen quality. Although normospermic semen is commonly assumed to behave as a low viscosity Newtonian fluid after liquefaction, we previously demonstrated a viscoelastic response consistent with weak gel-like behaviour. Here, we extend this analysis to 62 semen samples from infertility-diagnosed individuals and compare their rheological behaviour with normospermic samples. Both groups display similar steady shear viscosity and weak-gel characteristics in oscillatory measurements, but statistically significant differences in G″ at high frequencies, indicating altered microstructural dynamics in abnormal samples. Different correlations between rheological parameters and sperm motility are also found. These findings show that clinically relevant differences in semen rheology emerge under oscillatory conditions and support viscoelasticity as a complementary metric to conventional semen analysis.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 6","pages":"495 - 502"},"PeriodicalIF":3.0,"publicationDate":"2026-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148009517","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":"Viscosity functions of shear flows for fractional maxwell fluids","authors":"Rattanaporn Promjariyakoon,&nbsp;Pongthep Poungthong,&nbsp;Chanyut Kolitawong,&nbsp;Alan J. Giacomin","doi":"10.1007/s00397-026-01563-w","DOIUrl":"10.1007/s00397-026-01563-w","url":null,"abstract":"<div><p>Fractional calculus is applied increasingly to fluid dynamics. We derive exact analytical solutions for shear stress growth rheological responses of the fractional Maxwell fluid (FMF) in extra-stress tensor form. We do so by using the Laplace transform and its inverse. By <i>shear stress growth</i>, we mean the sudden inception of steady shear flow. We first determine the shear stress growth viscosity, then extend this to the steady shear viscosity using empirical Gleissle mirror relations. We choose to explore the FMF because of its four-parameter versatility and because it describes fluid elasticity measurements accurately. We compare with the ordinary non-fractional Maxwell fluid (OMF) in shear stress growth. Our FMF exact solution agrees well with available measurements on aqueous xanthan gum solutions, so long as the initial residual stresses in the sample are accounted for. We discover that, in practice, positive initial residual shear stress shifts the viscosity in shear stress growth downward. Finally, we construct concentration master curves for our xanthan gum solution shear stress growth rheological functions. We do so to generalize predictions of viscosity under varying conditions. Our worked examples illustrate how to use this dimensionless master curve.</p></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 6","pages":"543 - 562"},"PeriodicalIF":3.0,"publicationDate":"2026-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148009456","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":"A century later: a bearing-capacity framework to extract Mohr-Coulomb parameters from penetration tests","authors":"C. Maximilian Hechtl,&nbsp;Stefan Segl,&nbsp;Thomas Kränkel,&nbsp;Christoph Gehlen","doi":"10.1007/s00397-026-01562-x","DOIUrl":"10.1007/s00397-026-01562-x","url":null,"abstract":"<div>\u0000 \u0000 <p>This study reformulates classical bearing-capacity theory into a depth-resolved framework for extracting apparent Mohr–Coulomb parameters from quasi-static flat-punch penetration tests. The measured force–depth response is converted to the mean contact stress <span>(varvec{q(z)})</span> and analysed as a function of depth, with cohesive, surcharge, and unit-weight contributions. Under homogeneous, axisymmetric conditions, the internal friction angle <span>(varvec{varphi })</span> and cohesion <span>(varvec{c})</span> are obtained from the slope and intercept of the quasi-steady <span>(varvec{q(z)})</span> relation. Applied to an inert montmorillonite–glycerin reference material, the method yielded reproducible results across punch diameters <span>(varvec{D=20})</span>–<span>(varvec{40~textrm{mm}})</span>, giving <span>(varvec{varphi _{pen}approx 4.8^circ })</span> and <span>(varvec{c_{pen}approx 0.85~textrm{kPa}})</span>. Independent vane tests gave <span>(varvec{c_{textrm{vane}}approx 0.70~textrm{kPa}})</span>, and direct shear box tests yielded <span>(varvec{varphi _{textrm{dsb}}approx 4.45^circ })</span> and <span>(varvec{c_{textrm{dsb}}approx 1.16~textrm{kPa}})</span>. The friction angles from penetration and DSB testing were consistent, while the cohesion values differed in the ordering expected from their respective interface and deformation conditions. Within the quasi-static, low-stress regime examined here, the penetration-based approach provides an efficient method for quantifying apparent Mohr–Coulomb parameters of soft cohesive–frictional materials.</p>\u0000 </div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 5","pages":"475 - 486"},"PeriodicalIF":3.0,"publicationDate":"2026-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-026-01562-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147727497","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":"Anionic collagen processed by alkaline hydrolysis: rheological, biological, and 3D printability assessment","authors":"Lívia C. Massimino,&nbsp;Mirella R. V. Bertolo-Cagnoto,&nbsp;Larissa Tessaro,&nbsp;Virginia da C. A. Martins,&nbsp;Bianca Chieregato Maniglia,&nbsp;Ana Maria de G. Plepis,&nbsp;Monica B. Mathor","doi":"10.1007/s00397-026-01567-6","DOIUrl":"10.1007/s00397-026-01567-6","url":null,"abstract":"<div><p>Collagen is the most abundant structural protein in the extracellular matrix, and its biocompatibility can be enhanced by chemical modification into a negatively charged matrix. This study investigates the effect of alkaline hydrolysis time (24, 48, 72, and 96` h) on the rheological behavior and processability of anionic concentrated collagen solutions extracted from bovine tendon. By systematically modulating hydrolysis time, we demonstrate how increasing negative charge density drives a rearrangement of the collagen network, resulting in more elastic and shear-thinning behavior, as evidenced by higher storage moduli, increased zero-shear viscosity, and enhanced creep-recovery response. Among the tested formulations, the 72-h hydrolyzed collagen exhibited the most balanced rheological profile and enabled extrusion-based 3D printing with high fidelity, achieving geometry preservation of 104 ± 4% (star angle), 98 ± 2% (scaffold area), and effective macroporosity of 84%. Longer hydrolysis led to decreased scaffold pore size and increased absorption of phosphate-buffered saline. All materials were non-cytotoxic and supported cell adhesion (58.74—74.89%). Overall, this work highlights how rheological characterization can guide the design and processability of collagen-based bioinks, linking structural and mechanical properties to 3D printing performance and biological outcomes.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div></div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 6","pages":"503 - 523"},"PeriodicalIF":3.0,"publicationDate":"2026-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-026-01567-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148008655","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":"A portable liquid-in-liquid extensional tester","authors":"Andrew te Water Naude,&nbsp;Ben C. Atchison,&nbsp;Mikolaj Rycek,&nbsp;Callum S. Stephenson,&nbsp;D. Ian Wilson","doi":"10.1007/s00397-026-01565-8","DOIUrl":"10.1007/s00397-026-01565-8","url":null,"abstract":"<div>\u0000 \u0000 <p>A low-cost device designed to study filament thinning in the presence of a surrounding liquid is presented. Video analysis allows filament shape (diameter, curvature and reservoir behaviour) to be monitored. Results are reported for silicone oils with viscosities ranging from 0.5 to 5.0 Pa s in air, water, aqueous isopropanol mixtures and aqueous solutions of SDS, TX-100 (above and below the critical micelle concentration), human and bovine serum albumins. The evolution of filament diameter in these low Bond number tests exhibit viscous regime behaviour, with a transition between the Eggers (1993) and Papageorgiou (1995) results. In TX-100 and albumin solutions below the critical micelle concentration the thinning profiles suggest that mass transfer limitations affect the approach to filament breakup. At higher surfactant concentrations the reservoir shape deviates from that observed with clean solutions.</p>\u0000 <span>AbstractSection</span>\u0000 Graphical abstract\u0000 <div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div>\u0000 \u0000 </div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 6","pages":"525 - 541"},"PeriodicalIF":3.0,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00397-026-01565-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148008585","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":"Doros N. Theodorou and Vlasis G. Mavrantzas, Multiscale Modelling of Polymers","authors":"Yuichi Masubuchi","doi":"10.1007/s00397-026-01568-5","DOIUrl":"10.1007/s00397-026-01568-5","url":null,"abstract":"","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 6","pages":"575 - 576"},"PeriodicalIF":3.0,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148008646","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-link model predictions for the flow of entangled melts of star-branched and linear chains of similar span length","authors":"Maria Katzarova,&nbsp;Andrés Córdoba,&nbsp;Diego Becerra,&nbsp;Jay D. Schieber","doi":"10.1007/s00397-026-01560-z","DOIUrl":"10.1007/s00397-026-01560-z","url":null,"abstract":"<p>The nonlinear rheology of entangled polymers is strongly influenced by molecular architecture, yet architectural complexity does not necessarily translate into superior processing performance. Here, we investigate the transient shear and uniaxial elongation responses of symmetric star-branched and linear polystyrene chains of similar span length, using recent experimental data of Liu et al. (2025). Predictions are performed with the clustered fixed slip-link model (CFSM), a coarse-grained implementation of the discrete slip-link model, recently revised to accurately describe the mean-field constraint dynamics in star-branched polymers (Katzarova et al. Macromolecules, 59(1):564–574 2026). The model quantitatively reproduces the transient shear response for both architectures at moderately large Rouse-Weissenberg numbers (<span>(Wi_textrm{R}lesssim 2)</span>) and captures elongational stress growth up to Hencky strains of approximately two, achieving a level of agreement with experiment that is unprecedented for coarse-grained models in these nonlinear regimes. Consistent with prior experimental interpretations, we confirm theoretically that the Rouse-stretch time of symmetric star polymers can be estimated in the same manner as for linear chains, provided the span length is taken as twice the arm molecular weight. The results further suggest that, far-from-equilibrium, branch-point diffusion in star polymers plays a diminished role in the nonlinear response, highlighting an architectural effect relevant to polymer processing flows.</p>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 5","pages":"409 - 418"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147727357","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":"Rate-dependent relaxation time and viscoelastic properties of a silicone-based 3D printing material","authors":"Muhanna A. H Alrashdi,&nbsp;Valeria Diamanti,&nbsp;Hamada Elsayed,&nbsp;Giulio G. Giusteri","doi":"10.1007/s00397-026-01559-6","DOIUrl":"10.1007/s00397-026-01559-6","url":null,"abstract":"<p>We measure the rheological properties of a newly formulated silicone-based ink for additive manufacturing technologies. The basic measurement for such viscoelastic non-Newtonian fluids, namely small amplitude oscillatory shear (SAOS) highlights the need to consider a relaxation time of the polymeric microstructure that depends smoothly on the oscillation frequency. We incorporate this information within a recently developed framework for the tensorial description of viscoealastic fluids. With this, we can achieve a significant improvement in the fitting of the experimental data. Moreover, we can extrapolate the frequency dependence of the relaxation time to its rate dependence in steady shear flows, leading to a prediction of both the viscosity and the first normal stress coefficient which is in good agreement with experiments. This provides a new way to connect the linear viscoelastic response to the nonlinear response of the material.</p>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 5","pages":"487 - 494"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147727356","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":"On the measurement of linear viscoelastic moduli. A comparison between oscillatory (shear and squeeze) tests","authors":"F. J. Rubio-Hernández,&nbsp;M. Rodríguez-Lara,&nbsp;J. F. Velázquez-Navarro,&nbsp;J. Sánchez-Rodríguez,&nbsp;E. Carabias,&nbsp;J. A. Cabrera","doi":"10.1007/s00397-026-01566-7","DOIUrl":"10.1007/s00397-026-01566-7","url":null,"abstract":"<div>\u0000 \u0000 <p>Relationships between shear and squeeze linear viscoelastic moduli have been calculated assuming the fluid accomplishes with the Generalized Linear Viscoelastic Fluid constitutive equation. They only differ by a geometric factor determined by the squeeze tests, a result coinciding with that previously obtained by Wingstrand et al. (J Rheol 60:407–418, 2016) assuming the viscoelasticity of the fluid results from the use of a complex viscosity in the Generalized Newtonian Fluid constitutive equation. Three representative materials, i.e., honey (Newtonian), shampoo (viscoelastic liquid), and foam (viscoelastic solid), were experimentally tested to check the theoretical predictions. Despite it is not specifically designed for oscillatory squeeze tests, a texturometer was used after the repeatability of measurements in the frequency range <span>(:0.1-10:Hz)</span> was checked. Results were compared to those obtained with a stress-controlled shear rheometer, which were considered as reference values. The main conclusion of this research work is that the linear viscoelasticity of materials that are difficult to test adequately in rotational rheometers, can be studied by using squeeze oscillatory flow, no matter which constitutive equation governs their flow.</p>\u0000 </div>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 6","pages":"563 - 574"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148008777","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":"Simultaneous rheo-Raman characterization of crosslinking and crystallization in semi-crystalline Diels–Alder polymer networks","authors":"Jelle De Ceulaer,&nbsp;Ruth Cardinaels,&nbsp;Peter Van Puyvelde","doi":"10.1007/s00397-026-01558-7","DOIUrl":"10.1007/s00397-026-01558-7","url":null,"abstract":"<p>Dynamic covalent networks (DCNs) based on the thermoreversible Diels–Alder (DA) reaction offer a unique combination of reprocessability, recyclability, and tunable mechanical properties. When dynamic bonds are introduced on semi-crystalline polymers such as poly(<span>(varepsilon)</span>-caprolactone) (PCL), their solidification is governed by the interplay of the chemical crosslinking reaction and the physical crystallization. However, conventional characterization techniques typically probe these mechanisms separately on distinct samples, whereas both mechanisms are convoluted in the rheological response. This makes it difficult to disentangle their simultaneous effects under processing-relevant conditions. Therefore, a hyphenated rheo-Raman technique is proposed that enables the <i>in situ</i> and simultaneous monitoring and correlation of both macroscopic rheological properties and microscopic molecular-level transformations during DA network formation and PCL crystallization. Isothermal experiments reveal an excellent agreement between Raman-derived and rheological gelation, confirming the reliability of spectroscopic tracking for dynamic network formation. Crystallization studies reveal that pre-existing crosslinks slow down crystallization. However, the Raman spot size highlights spatial restrictions arising from spherulitic growth and nucleation density, which can cause delays in local crystallinity tracking relative to bulk crystallization. Additionally, non-isothermal cooling experiments demonstrate how thermal history and cooling rate dictate the relative progression of crystallization and DA crosslinking. Together, these findings establish rheo-Raman spectroscopy as a powerful technique to decouple and quantify complex and interacting solidification pathways in semi-crystalline DCNs. The resulting insights provide a new experimental foundation to tailor improved structure–property relationships in dynamic covalent networks, with direct relevance to advanced processing methods such as additive manufacturing.</p>","PeriodicalId":755,"journal":{"name":"Rheologica Acta","volume":"65 5","pages":"441 - 456"},"PeriodicalIF":3.0,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147727413","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}