Log in

Relevant bibliographies by topics / Elongational rheology

Academic literature on the topic 'Elongational rheology'

Author: Grafiati

Published: 6 July 2024

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Elongational rheology.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Contents

Journal articles
Dissertations / Theses
Books
Book chapters
Conference papers

Journal articles on the topic "Elongational rheology":

1

Koyama, Kiyohito. "Melt Rheology (Elongational Viscosity)." Kobunshi 41, no. 2 (1992): 102–5. http://dx.doi.org/10.1295/kobunshi.41.102.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Wei, X., J. R. Collier, and S. Petrovan. "Shear and elongational rheology of polyethylenes with different molecular characteristics. II. Elongational rheology." Journal of Applied Polymer Science 104, no. 2 (2007): 1184–94. http://dx.doi.org/10.1002/app.25757.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Seyfzadeh, B., and J. R. Collier. "Elongational rheology of polyethylene melts." Journal of Applied Polymer Science 79, no. 12 (2001): 2170–84. http://dx.doi.org/10.1002/1097-4628(20010321)79:12<2170::aid-app1025>3.0.co;2-e.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Watanabe, Hiroshi, and Yumi Matsumiya. "Revisit the Elongational Viscosity of FENE Dumbbell Model." Nihon Reoroji Gakkaishi 45, no. 4 (2017): 185–90. http://dx.doi.org/10.1678/rheology.45.185.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Xu, Hai Hang, Lei Zhong, and Ji Zhao Liang. "Elongational Rheology of LLDPE by Melt Spinning Technique." Advanced Materials Research 146-147 (October 2010): 323–26. http://dx.doi.org/10.4028/www.scientific.net/amr.146-147.323.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Elongational rheology of LLDPE was studied by melt spinning technique. It was observed that the melt strength of LLDPE decreased with the rise of temperature, and the melts with lower elongational viscosities often broke at higher draw ratio. The melt strength activation energy was calculated by the slope of Arrhennius plots. The curves of elongational stress and viscosity under different conditions were drawn and compared, the results showed that with the increase of strain rate, the elongational stress rose and the viscosity decreased, both stress and viscosity dropped with the rise of temperature, and higher extrusion velocity caused lower elongational stress and viscosity.

6

Grumbein, S., M. Werb, M. Opitz, and O. Lieleg. "Elongational rheology of bacterial biofilmsin situ." Journal of Rheology 60, no. 6 (November 2016): 1085–94. http://dx.doi.org/10.1122/1.4958667.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Collier, J., S. Petrovan, P. Patil, and B. Collier. "Elongational rheology of fiber forming polymers." Journal of Materials Science 40, no. 19 (October 2005): 5133–37. http://dx.doi.org/10.1007/s10853-005-4402-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Stadler, Florian J., Tatjana Friedrich, Katharina Kraus, Bernd Tieke, and Christian Bailly. "Elongational rheology of NIPAM-based hydrogels." Rheologica Acta 52, no. 5 (March 12, 2013): 413–23. http://dx.doi.org/10.1007/s00397-013-0690-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Kolitawong, Chanyut. "Rheology properties of elongational flow experiments." Journal of Applied Science 18, no. 2 (December 3, 2019): 116–40. http://dx.doi.org/10.14416/j.appsci.2019.09.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Ferguson, J., and N. E. Hudson. "Transient elongational rheology of polymeric fluids." European Polymer Journal 29, no. 2-3 (February 1993): 141–47. http://dx.doi.org/10.1016/0014-3057(93)90074-p.

Full text

APA, Harvard, Vancouver, ISO, and other styles

More sources

Dissertations / Theses on the topic "Elongational rheology":

1

Greener, James. "Elongational flow in ceramics processing." Thesis, Brunel University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294511.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Carter, Brandt Kennedy. "Polymer structure and property studies in elongational rheology, spherulite deformation, and biaxial strain induced crystallization." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/74785.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

A small scale, highly accurate elongational viscometer was developed explicitly for the rheological investigation of well characterized polyethylene samples. Elongational stress growth measurements as well as dynamic shear experiments demonstrated that the rheological response of molten polyethylene was sensitive to both molecular weight distribution and shear modification. The effects of molecular weight distribution and shear modification were rationalized from a molecular point of view. A model is proposed which is based on the concept of a molecular network and incorporates polymer chain entanglement disruption and regeneration. Direct observations of polymeric semicrystalline morphologies in a copolyester by scanning electron microscopy were made possible by the development of a novel chemical etch. Spherulitic textures were consistent with classic spherulite growth mechanisms and structure theories. Uniaxial deformation of a single spherulite was successfully studied in a model system consisting of isolated spherulites embedded in an amorphous polymer matrix. By isolating the spherulite, the mechanical influence of surrounding and often impinging spherulites found in most semicrystalline polymers on the mechanical response of an individual spherulite was avoided. The mechanical response of the amorphous matrix was characterized and found to correlate with the effectiveness of a cold draw neck in elongating an embedded spherulite. The observed mechanism and morphology of isolated spherulite deformation were rationalized within the context of existing theories of spherulite-to-microfibrillar transitions. Optically active poly(L-lactic acid) and racemic poly(lactic acid) were synthesized in a ring opening polymerization scheme with stannous octoate as a catalyst and lactic acid as a molecular weight controlling initiator. Binary polymer blends composed of these isomeric polymer pairs were found to be miscible at 40,000 molecular weight and immiscible at 120,000 molecular weight. Strain hardening and the level of strain induced crystallization which occurred in the biaxial deformation of poly(lactic acid) blend films were found to be contingent on the concentration of optically active poly(L-lactic acid). Temperature, molecular weight, and biaxial strain rate were also found to have an influence on strain hardening and strain induced crystallization of these thermodynamically ideal polymer blends.
Ph. D.

3

Velu, Nanjunda Shanmuga. "Rhéologie élongationelle de composites à base de polyoléfines : Une étude expérimentale et modélisation." Electronic Thesis or Diss., Lyon, 2021. http://www.theses.fr/2021LYSES015.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Les polymères ayant un comportement rhéo-épaississants sous écoulement élongationnel sont préférés pour certains procédés industriels telles que le thermoformage, le moulage par soufflage, etc. De plus, des charges inorganiques rigides sont généralement ajoutées pour conférer des propriétés fonctionnelles spécifiques à ces polymères. Un état de l’art sur le sujet montre que l’ajout de charges modifie la nature de l’écoulement élongationnel. Selon la nature de la matrice, c’est-à-dire rhéo-épaississant ou comportement linéaire, les composites à l’état fondu présentent soit une suppression du comportement rhéo-épaississant, soit un comportement rhéo-fluidifiant par rapport à la matrice pure, ce qui induit des difficultés de mise en œuvre. L’origine du comportement rhéo-fluidifiant sous écoulement élongationnel des composites à l’état fondu n’a pas été précisement abordé dans la littérature. Dans ce travail de thèse, nous étudions l’effet de particules inorganiques sur le comportement rhéologique de polyoléfines. Pour répondre à la question sur l’origine de la rhéo-fluidification ou de la suppression du rhéo-épaississement dans les composites à l’état fondu, nous avons étudié une matrice linéaire (EPDM) et une matrice rhéo-épaississante (Pebd) chargées de deux silices hydrophiles de taille nanométrique ou micrométrique. L’effet de la réticulation par rayonnement sur le comportement élongationnel des composites EPDM-silice nanométrique a également été étudié. Les composites contenant une matrice d’EPDM présentent un comportement rhéo-fluidifiant, tandis que les composites à matrice PEbd ne présentent qu’une réduction du rhéo-épaississement sans rhéo-fluidification. Les composites EPDM-nano-silice réticulés présentent un comportement plus complexe, avec une rhéo-fluidification initiale suivi d’un rhéo-épaississement aux temps longs. Pour modéliser le comportement sous écoulement élongationnel des composites polymères fondus, nous avons utilisé le modèle de Leonov pour le système EPDM-silice fractale et avons discuté ses inconvénients inhérents. Pour les surmonter, nous avons quantifié l’effet du cisaillement interparticulaire en développant deux modèles, le modèle « Leapfrog » qui n’inclut pas l’effet de couplage des contributions d’élongation et de cisaillement et une théorie de champ moyen qui prend en compte cet couplage. Le modèle « Leapfrog » est capable de prédire le comportement élongationnel des composites EPDM-nano-silice mais sous-estime les niveaux de viscosité pour les systèmes à base de PEbd. Par contre, la théorie de champ moyen permet de modéliser avec succès et un nombre de paramètres très limité, le comportement élongationnel de tous les systèmes considérés, c’est-à-dire quelque soit le comportement rhéologique de la matrice pure ou de la nature des particules
Polymers with a strain hardening behaviour under extensional flow is preferred for certain industrial processing techniques such as thermoforming, blow-molding, etc. Rigid inorganic fillers are commonly added to impart specific functional properties to polymers. A review of the works reported in literature show that addition of fillers modify the nature of extensional flow. Depending upon the nature of the matrix, i.e. strain hardening or a linear behaviour, the composite melts show either a suppression in strain hardening or a strain softening behaviour in comparison to the matrix, posing difficulties in processing. However, the origin of the elongational thinning behaviour in composite melts has not been addressed previously. In this thesis work, we investigate the effect of filler particles on the extensional rheo logical behaviour of polyolefins. To address the question on the origin of strain softening or suppression in the composite melts, we have studied the effect of a linear matrix as well as a strain hardening matrix. The linear matrix used in this study is EPDM and for a strain hardening matrix, LDPE is used. For fillers, we have used both fractal silica and micro sized silica beads. The effect of radiation cross-linking on the extensional behaviour of EPDM-fractal silica composites has also been investigated. Composites containing EPDM matrix show a strain softening behaviour whereas composites containing LDPE show only a suppression in strain hardening and not strain softening. Cross-linked EPDM-fractal silica composites show a complex extensional behaviour, with an initial strain softening followed by strain hardening at long times. To model the extensional behaviour of polymer composite melts, we develop the Leonov model for the EPDM-fractal silica system and discuss it’s inherent drawbacks. To overcome these drawbacks, we attempt to quantify the effect of interparticle shear by developing two models, the Leapfrog model that does not include the coupling effect of extensional and shear contributions and the Mean-field theory that takes into account the coupling effect. The Leapfrog model is able to predict the extensional behaviour of EPDM-fractal silica composites but underestimates the viscosity levels for LDPE based systems where the matrix is strain hardening. The Mean-field theory can model the extensional behaviour of all the systems under consideration, i.e. both linear matrix and strain hardening matrix with a reduced number of parameters

4

Mahmud, Arif. "Non-colloidal Suspensions Rheology – An Experimental Study." Thesis, University of Sydney, 2019. https://hdl.handle.net/2123/22891.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

To get a complete scenario of the rheological behaviour of non-colloidal suspension it is important to explore the transient shearing, elongational, and oscillatory shearing as well as simple steady shearing. The thesis includes new experiments and comparisons with the few theories available. The simple steady shearing and elongation flow behaviour of non-colloidal suspensions were studied. Simple shear-thinning effects were discussed and the elongational phenomena in non-colloidal suspensions were investigated, where transient shearing was also considered. The thinning effects in non-colloidal suspension were studied from different experiments and simulations. Shear-thinning was clear on 40% volume fraction suspensions. The shear-thinning depends on the variation of the interparticle friction coefficient with the shear rate or shear stress. The transient result did not replicate Gadala‐Maria and Acrivos (1980) results. They performed their test 40 years ago using similar suspensions and we believe the variation may be due to the better performance/sensitivity of the newer rheometers. We developed a new setup to perform the elongational test and the motion of the fluid drops was filmed with a high-speed FASTCAM PCI R2 (Photron) camera. The reduction in diameter of the drop with time indicates the elongation rate; pure elongation was seen where the diameter was minimum. To investigate the changes in elongational viscosity of 12500 cs Silicone oil suspension, a steel ball was introduced with the suspensions this improves the filament shape – it is more uniform. We assumed the rate of elongation (ε ̇) was constant over the cross-section (but varied at different times); the rate of elongation was then found using the variation in diameter with time (Dai and Tanner, 2017). Friction plays a significant role in non-colloidal suspension and it becomes more complex at higher concentration of suspension. A “bootstrap” feedback model was proposed (Tanner et al., 2018) which shows how friction amplifies the stress and increases the complexity of the suspension behaviour. The bootstrap mechanism of friction enhancement in non-colloidal suspensions appears to be a useful idea. In view of the confusing picture reported by others, it was decided to make further measurements of small and medium strain oscillatory flows keeping in mind possible friction between particles. Because of the observed tendency to hysteresis, the oscillatory flow was combined with the parallel steady shear flow to control or eliminate hysteresis. The response of concentrated suspensions under oscillatory shear is surprisingly complex, and it becomes more complex when oscillatory shearing and steady shearing are combined. The non-zero storage modulus experienced due to frequency sweep tests in a glycerine matrix was an apparent storage modulus which was due to inertia effects (which were very small). We observed a slight decline in G^' and G^'' with an increase of strain amplitude and we believe settling is not responsible. Surprising hysteresis effects were experienced by both moduli with increased and decreased strain amplitude. The hysteresis was more dominant in the storage modulus than in the loss modulus and at higher concentrations the effect was severe. In simple steady shearing, friction increases the suspension viscosity, and we believe both G^' and G^'' also increase due to friction. The effect of variable oscillatory shear stress and steady shear stress was analysed and a model for superposed storage modulus, loss modulus and viscosity responses was proposed. Frictional effects were considered in the proposed model and satisfactory fitting with the experimented data was observed. The ‘bootstrap’ feedback mechanism was adapted to explain frictional effects. We proposed a universal model for non-colloidal suspensions. This is a modified Reiner-Rivlin inelastic model (eq. 5.9) which is a reasonable description of available tests of suspensions with Newtonian matrices in several flows for larger strains. Further checks are needed, and the quest must continue for more basic understanding. Nevertheless, the modified Reiner-Rivlin model is simple to apply and should be useful for numerical work on the concentrated suspensions.

5

Ahirwal, Deepak. "Large deformation shear and elongation rheology of polymers for electrospinning and other Industrial Processes." Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-01065971.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

The goals of this thesis are the characterization of polymer melts using mainly non-linear shear and extensional rheological techniques. The fabrication of scaffolds with excellent physical and mechanical properties using solution electrospinning technology for tissue engineering applications and the development of melt electrospinning equipment to facilitate the fabrication of solvent free scaffolds. To achieve the first goal, we focused on the characterization of entangled polymer melts in the linear and nonlinear viscoelastic regimes. The influence of molecular weight, Mw, molecular weight distribution (MWD), long-chain branching (LCB) and addition of particles to the polymer matrix on polymer melt properties were investigated using shear and extensional rheological techniques. The resulting structure-property relationships were established using newly introduced mechanical parameters under large amplitude oscillatory shear (LAOS) flow.

6

Zhang, Huagui. "Fundamental studies of interfacial rheology at multilayered model polymers for coextrusion process." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0163.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Les travaux de cette thèse concernent des études fondamentales liées à la rhéologie interfaciale des systèmes polymères multicouches. Les matériaux choisis sont à base de deux polymères compatibles,PVDF et PMMA de différentes masses molaires. Ces systèmes ont été étudiés sous sollicitations en cisaillement et en élongation suivant les deux régimes en viscoélasticité linéaire (VEL) et non-linéaire (VENL). Les études en VEL ont permis d’étudier la cinétique de développement de l’interphase. Quant aux études en VENL, elles ont permis d’étudier les propriétés intrinsèques de l’interphase simulant ainsi les conditions de mise en œuvre proches de celles des procédés usuels. On démontre ainsi que la rhéologie joue le rôle d’une sonde très fine pour explorer les propriétés aux interfaces des matériaux multicouches. Des modélisations ont été établies en se basant sur les mécanismes physiques mis en jeu. Dans un premier temps, le comportement rhéologique à l’état fondu des multicouches a été étudié par spectrométrie mécanique dynamique en VEL. Les cinétiques d'interdiffusion ainsi que le développement de l’interphase générée aux interfaces de bicouches symétriques et asymétriques ont été étudiés. Les résultats obtenus ont été analysés et modélisés en se basant sur les concepts de la dynamique moléculaire en l’occurrence le modèle de Doi et Edwards. De plus, un nouveau modèle rhéologique a été développé. Il a permis de quantifier les coefficients d'interdiffusion. Les coefficients de friction des chaines et les propriétés rhéologiques de l’interphase ont été modélisés à leur tour. Les résultats obtenus corroborent ceux de la littérature, obtenus par des méthodes spectroscopiques sophistiquées. Le modèle a permis de quantifier les grandeurs viscoélastiques et l’épaisseur de l’interphase. Dans un second temps, des expérimentations en VENL ont été réalisées. Un modèle original a été également proposé pour décrire le comportement relatif à la relaxation des multicouches et de l'interphase. De plus, la sensibilité de la densité d’enchevêtrement a été étudiée pendant et après sollicitations. On démontre que sa présence retarde l'écoulement interfacial surtout sous hautes déformations et vitesses de déformation. En outre, les études des structures multicouches sous sollicitation élongationnelle ont montrées que les propriétés dépendent du rapport de viscosité des couches et les propriétés de l’interphase diffuse. Les travaux de cette thèse mettent en lumière la compétition entre l’effet négatif de l'orientation des chaînes et l'effet favorable de l'écoulement sur les cinétiques de la diffusion. Ensuite, des cartes de stabilités des écoulements stratifiés ont été établies.. La présence de l'interphase diffuse a contribué à une élimination des instabilités. On montre ainsi qu’outre la cinématique de l’écoulement en cisaillement et en élongation, les propriétés de l’interphase ont un rôle important dans la stabilité des écoulements stratifiés en coextrusion
Fundamental studies have been devoted in this work to probe and modelize the interfacial phenomena at multilayered polymer systems based on two model compatible polymers of PVDF and PMMA with varying molar masses. Linear and nonlinear rheology have been demonstrated to be sensitive to the presence of diffuse interphase triggered from interdiffusion at polymer/polymer interface. Firstly, the interdiffusion kinetics as well as the development of the interphase decoupled to flow as generated at a symmetrical (self diffusion) and an asymmetrical (mutual diffusion) bilayer have been investigated using small-amplitude oscillatory shear measurements. Results were analyzed according to Doi-Edwards theory (tube model) and the effects of annealing factors as well as structural properties on the diffusion kinetics have been studied. The PMMA/PVDF mixtures have been examined to be a couple of weak thermorheological complexity, owning close monomeric friction coefficients of each species in the present experimental conditions. Based on this physics, a new rheological model was developed to quantify the interdiffusion coefficients by taking into account the component dynamics in mixed state and the concept of interfacial rheology. Rheological and geometrical properties of the interphase have been able to be quantified through this model, as validated by scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM-EDX) and transmission electron microscopy (TEM). Secondly, experiments of step strain, startup in simple shear and in uni-axial extension have been carried out on the PMMA/PVDF multilayer structures. An original model was proposed to fit the stress relaxation behavior of multilayer structures and to estimate the relaxation behavior of the interphase. Lack of entanglement at the interface and weak entanglement intensity at the diffuse interphase make them to be subsequently readily to suffer from interfacial yielding even interfacial failure during and after continuous large deformations. Interphase delays the interfacial yielding to a larger external deformation or a higher deformation rate. Besides, elongational properties of the multilayer structures have been shown to be a function of composition as controlled by layer number(interfacial area) and interphase properties (rheology related to entanglement intensity). Finally, the diffuse interphase development coupled to flow in practical coextrusion process has been considered. The compromising result between negative effect of chain orientation and favorable effect of flow on diffusion kinetics gives rise to a broadening interphase after coextrusion. Presence of the diffuse interphase was demonstrated to significantly weaken (or even eliminate) the viscous and elastic instabilities despite of the high rheological contrast. Hence, this work gives guidelines on the key role of the interphase plays in structure-property-processing relationships

7

Harris, Patrick James. "LAYERED POLYMERIC SYSTEMS:NEW PROCESSING METHODS AND NOVEL MECHANICAL DESIGN IN EXTENSIONAL RHEOLOGY." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1410544432.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Kowalski, Sebastian. "Rheology based investigation of a polymer-mineral powder mix for low pressure injection moulding." Limoges, 2005. http://aurore.unilim.fr/theses/nxfile/default/80dadd89-fb07-4918-8b88-5fd642b79cac/blobholder:0/2005LIMO0015.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

La pâte céramique étudiée, mélange de plusieurs polymères immiscibles : paraffine, EVA, cire de carnauba et d'une poudre minérale submicronique est utilisée dans le procédé d'injection. On s'est surtout attaché à corréler les propriétés rhéologiques à 130°C à la physico-chimie du system. Plusieurs paramètres ont été modifiés, - la fraction volumique, la composition du mélange de polymères et la nature de la poudre. On a montré que les molécules d'EVA et de carnauba sont adsorbées sur la surface de ZrO2, dans un rapport volumique de 2/1 et la poudre fait des inclusions dans la paraffine. Pour une fraction volumique >50% vol. , la pâte se comporte comme un solide et montre des propriétés de thixotropie – analysées avec un modèle développé par Piau. Un rhéomètre capillaire a été utilisé pour estimer la viscosité élongationelle, qui est très sensible (contraire à la viscosité de cisaillement), et clairement lié à la quantité d'EVA adsorbé
. The rheological properties of a ceramic paste, comprising several immiscible polymers : paraffin wax, EVA, carnauba wax, mixed with a mineral submicronic powder were investigated at 130°C. It is a prerequisite to master a forming process such as injection moulding and this was one of the pursued objectives. The other one was to relate these properties to the physico-chemical composition. Several parameters were modified i. E. - the vol. Solid fraction, the polymer blend composition and the nature of the powder. It was proved that EVA and carnauba molecules adsorb on ZrO2 surface, in a volume ratio 2/1 and the powder makes inclusions in the liquid paraffin. For a vol. Fraction >50%, a solid-liquid transition occurs - paste shows a thixotropic behaviour-analyzed with a model developed by Piau. A capillary rheometer was used to estimate the extensional viscosity, which is very sensitive (contrary to shear viscosity), and clearly related to the amount of adsorbed EVA

9

Oh, Kyung Hee. "Effect of shear, elongation and phase separation in hollow fiber membrane spinning." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53992.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

The spinning process of hollow fiber membranes was investigated with regards to two fundamental phenomena: flow (shear and elongation) and phase separation. Quantitative analysis of phase separation kinetics of binary (polymer/solvent) and ternary (polymer/solvent/volatile co-solvent) polymer solution was carried out with a newly developed microfluidic device. The device enables visualization of in situ phase separation and structure formation in controlled vapor and liquid environments. Results from these studies indicated that there was a weak correlation between phase separation kinetics and macroscopic defect (macrovoid) formation. In addition, the effect of shear and elongation on membrane morphology was tested by performing fiber extrusion through microfluidic channels. It was found that the membrane morphology is dominated by different factors depending on the rate of deformation. At high shear rates typical of spinning processes, shear was found to induce macrovoid formation through normal stresses, while elongation suppressed macroscopic defect formation. Furthermore, draw resonance, one of the key instabilities that can occur during fiber spinning, was investigated. It was found that draw resonance occurs at aggressive elongation condition, and could be suppressed by enhanced phase separation kinetics. These results can be used as guidelines for predicting hollow fiber membrane spinnability.

10

Zhang, Xiao. "Glissement et élongation des fluides à seuil." Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1037/document.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Le ketchup, la moutarde, la mousse à raser, sont des fluides à seuil, ils s’écoulent uniquement lorsqu’on leur applique une contrainte supérieure à une valeur critique, appelée contrainte seuil. Sur des surfaces lisses, ces fluides peuvent s’écouler sous de petites contraintes : on a alors un phénomène de glissement. En étudiant par rhéométrie les écoulements de ces matériaux des séquences originales et une technique d’imagerie directe (vélocimétrie en IRM), on montre que le glissement ne se produit qu’au-delà d’une contrainte critique. Selon les cas, cette contrainte critique est due soit à un effet de bord, soit à un effet de surface. L’excès de contrainte par rapport à cette contrainte critique varie linéairement avec la vitesse de glissement. De ce fait le glissement peut être représenté comme le cisaillement d’une couche de liquide le long de la paroi, mais la réalité est plus complexe compte tenu de la structure du matériau au contact avec la paroi. Curieusement l’épaisseur de cette couche de liquide « équivalente » ne semble pas varier avec la concentration, la taille des gouttes, la force normale, etc. Ceci suggère que cette épaisseur est gouvernée par des forces plus élevées que la lubrification et la pression osmotique. Nous étudions également le glissement pour des écoulements plus complexes. Pour cela on impose une élongation au fluide à seuil par une expérience de traction avec des surfaces lisses. La force normale mesurée pour différents matériaux avec des structures différentes montre que la condition de transition solide-liquide en élongation est différente que ce que prédit la théorie standard, et l’épaisseur de la couche de glissement est de plusieurs ordres de grandeur supérieure à celle trouvée en cisaillement simple
Ketchup, mustard, shaving creams flow only when submitted to stresses greater than a critical stress – yield stress, these are yield stress fluids. On smooth surfaces, these fluids can flow under very small stresses; this phenomenon is the wall slip. Using gels, emulsions, clay suspensions, etc., and from rheometrical tests with original protocols and internal measurements (MRI velocimetry), we show that a minimal stress must be reached to initiate wall slip and, depending on cases, this value is either due to an edge effect or to an adhesion of the suspended elements to the wall. Above this critical value, the excess of stress is found to vary linearly with the slip velocity, except at the transition of the yield stress or using a microtextured surface: in that cases the relation becomes quadratic. The wall slip can be interpreted as the shear flow of a thin liquid layer between the yield stress fluid and the wall. However, given the complexity of the material structure in contact with the wall, the exact picture of the slip layer requires further investigations. The apparent thickness of the liquid layer seems to be independent of the concentration, the mean droplet size, the external normal forces, etc., suggesting that it depends on interactions between the suspended droplets and the surface which are much stronger than the lubricating and osmotic pressures. We also study wall slip under more complex flow conditions, by inducing an elongational flow during a traction test with smooth surfaces. The normal force measured for various materials with different microstructures shows that the yielding condition in an elongational flow is different from the standard theory, and the apparent thickness of the wall slip layer is several orders of magnitude larger than that found in shear flows

Books on the topic "Elongational rheology":

1

1949-, Nguyen Q. Tuan, and Kausch H. H, eds. Flexible polymer chains in elongational flow: Theory and experiment. Berlin: Springer, 1999.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

2

Nguyen, Tuan Quoc. Flexible Polymer Chains in Elongational Flow: Theory and Experiment. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

3

(Editor), Tuan Q. Nguyen, and Hans-Henning Kausch (Editor), eds. Flexible Polymer Chains in Elongational Flow: Theory and Experiment. Springer, 1999.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Elongational rheology":

1

Müller, A. J., and A. E. Sáez. "The Rheology of Polymer Solutions in Porous Media." In Flexible Polymer Chains in Elongational Flow, 335–93. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-642-58252-3_11.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Crúz-Mena, J., F. Serranía, and B. Mena. "Elongational Rheometry with Pre-Shearing History." In Progress and Trends in Rheology V, 461–62. Heidelberg: Steinkopff, 1998. http://dx.doi.org/10.1007/978-3-642-51062-5_223.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Mena, B. "A Simple Measurement of Elongational Viscosity." In Third European Rheology Conference and Golden Jubilee Meeting of the British Society of Rheology, 355–57. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-0781-2_123.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Koyama, Kiyohito, Takashi Ota, and Katsufumi Tanaka. "Elongational Flow Behavior of Supercooled Polyethylene Melt." In Third European Rheology Conference and Golden Jubilee Meeting of the British Society of Rheology, 286–88. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-0781-2_100.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Schümmer, P., and H. G. Thelen. "History effects in elongational flow of polymer solutions." In Progress and Trends in Rheology II, 192–95. Heidelberg: Steinkopff, 1988. http://dx.doi.org/10.1007/978-3-642-49337-9_61.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Gotsis, A. D., and M. A. Odriozola. "Elongational Viscosity of a Thermotropic Liquid Crystalline Polymer." In Progress and Trends in Rheology V, 222–23. Heidelberg: Steinkopff, 1998. http://dx.doi.org/10.1007/978-3-642-51062-5_101.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Münstedt, H., and S. Kurzbeck. "Elongational Behaviour and Molecular Structure of Polymer Melts." In Progress and Trends in Rheology V, 41–44. Heidelberg: Steinkopff, 1998. http://dx.doi.org/10.1007/978-3-642-51062-5_13.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Hernandez Cifre, J. G., and J. Garcia. "Simulation of Polymer Solutions in Steady Elongational Flow." In Progress and Trends in Rheology V, 332–33. Heidelberg: Steinkopff, 1998. http://dx.doi.org/10.1007/978-3-642-51062-5_157.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Bernnat, A., and M. H. Wagner. "Rheotens Experiments and Elongational Behaviour of Polymer Melts." In Progress and Trends in Rheology V, 375–76. Heidelberg: Steinkopff, 1998. http://dx.doi.org/10.1007/978-3-642-51062-5_179.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Koyama, K., and O. Ishizuka. "Elongational viscosity of polymer melts using a constant stress rheometer." In Progress and Trends in Rheology II, 191–92. Heidelberg: Steinkopff, 1988. http://dx.doi.org/10.1007/978-3-642-49337-9_60.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Elongational rheology":

1

Münstedt, Helmut. "Elongational experiments on polymer melts and their assessment." In NOVEL TRENDS IN RHEOLOGY V. AIP, 2013. http://dx.doi.org/10.1063/1.4802610.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Rolón-Garrido, Víctor H., and Manfred H. Wagner. "Photo-oxidation of LDPE: Effects on elongational viscosity." In NOVEL TRENDS IN RHEOLOGY V. AIP, 2013. http://dx.doi.org/10.1063/1.4802614.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Ouchi, Mayumi, Takatsune Narumi, Tomiichi Hasegawa, Tsutomu Takahashi, Masataka Shirakashi, Albert Co, Gary L. Leal, Ralph H. Colby, and A. Jeffrey Giacomin. "Elongational Deformation of DNA Polymers in Micro Flow." In THE XV INTERNATIONAL CONGRESS ON RHEOLOGY: The Society of Rheology 80th Annual Meeting. AIP, 2008. http://dx.doi.org/10.1063/1.2964908.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Hirschberg, Valerian, Max G. Schußmann, and Marie-Christin Röpert. "Shear and elongational rheology of model polystyrene pom-poms." In NOVEL TRENDS IN RHEOLOGY IX. AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0159506.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Kaschta, Joachim, Helmut Münstedt, Albert Co, Gary L. Leal, Ralph H. Colby, and A. Jeffrey Giacomin. "Measuring the Elongational Properties of Polymer Melts—a Simple Task?" In THE XV INTERNATIONAL CONGRESS ON RHEOLOGY: The Society of Rheology 80th Annual Meeting. AIP, 2008. http://dx.doi.org/10.1063/1.2964481.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Kheirandish, Saeid, Ilshat Guybaidullin, Wendel Wohlleben, Norbert Willenbacher, Albert Co, Gary L. Leal, Ralph H. Colby, and A. Jeffrey Giacomin. "Shear and Elongational Flow Behavior of Inhomogeneous, Acrylic Thickener Solutions." In THE XV INTERNATIONAL CONGRESS ON RHEOLOGY: The Society of Rheology 80th Annual Meeting. AIP, 2008. http://dx.doi.org/10.1063/1.2964758.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Wagner, Manfred Hermann, Wang Zheng, Peng Wang, Sebastián Ramos Talamante, and Esmaeil Narimissa. "Shear and elongational rheology of photo-oxidative degraded HDPE and LLDPE." In NOVEL TRENDS IN RHEOLOGY VII. Author(s), 2017. http://dx.doi.org/10.1063/1.4982984.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Yamaguchi, Masayuki, Jiraporn Seemork, Panitha Phulkerd, and Mohd Amran Bin Md Ali. "Modification of rheological responses under elongational flow at non-isothermal condition." In NOVEL TRENDS IN RHEOLOGY IX. AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0159550.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Rasmussen, Henrik Koblitz, Anne Ladegaard Skov, Jens Kromann Nielsen, Philippe Laille, Ole Hassager, Albert Co, Gary L. Leal, Ralph H. Colby, and A. Jeffrey Giacomin. "Elongational Dynamics of Narrow Molar Mass Distribution Linear and Branched Polystyrene Melts." In THE XV INTERNATIONAL CONGRESS ON RHEOLOGY: The Society of Rheology 80th Annual Meeting. AIP, 2008. http://dx.doi.org/10.1063/1.2964712.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

TAKAHASHI, Tsutomu, Masataka SHIRAKASHI, Albert Co, Gary L. Leal, Ralph H. Colby, and A. Jeffrey Giacomin. "Evaluation of Planar Elongational Viscosity by Drag Force Acting on a Bullet Bob." In THE XV INTERNATIONAL CONGRESS ON RHEOLOGY: The Society of Rheology 80th Annual Meeting. AIP, 2008. http://dx.doi.org/10.1063/1.2964490.

Full text

APA, Harvard, Vancouver, ISO, and other styles