Journal of Rheology最新文献_第4页

3D manipulation and dynamics of soft materials in 3D flows 三维流动中软材料的三维操纵和动力学

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-06-15 DOI: 10.1122/8.0000600

Michael Q. Tu, Hung V. Nguyen, Elliel Foley, M. I. Jacobs, Charles M. Schroeder

{"title":"3D manipulation and dynamics of soft materials in 3D flows","authors":"Michael Q. Tu, Hung V. Nguyen, Elliel Foley, M. I. Jacobs, Charles M. Schroeder","doi":"10.1122/8.0000600","DOIUrl":"https://doi.org/10.1122/8.0000600","url":null,"abstract":"Flow-based manipulation of particles is an essential tool for studying soft materials, but prior work has nearly exclusively relied on using two-dimensional (2D) flows generated in planar microfluidic geometries. In this work, we demonstrate 3D trapping and manipulation of freely suspended particles, droplets, and giant unilamellar vesicles in 3D flow fields using automated flow control. Three-dimensional flow fields including uniaxial extension and biaxial extension are generated in 3D-printed fluidic devices combined with active feedback control for particle manipulation in 3D. Flow fields are characterized using particle tracking velocimetry complemented by finite-element simulations for all flow geometries. Single colloidal particles (3.4 μm diameter) are confined in low viscosity solvent (1.0 mPa s) near the stagnation points of uniaxial and biaxial extensional flow for long times (≥10 min) using active feedback control. Trap stiffness is experimentally determined by analyzing the power spectral density of particle position fluctuations. We further demonstrate precise manipulation of colloidal particles along user-defined trajectories in three dimensions using automated flow control. Newtonian liquid droplets and GUVs are trapped and deformed in precisely controlled uniaxial and biaxial extensional flows, which is a new demonstration for 3D flow fields. Overall, this work extends flow-based manipulation of particles and droplets to three dimensions, thereby enabling quantitative analysis of colloids and soft materials in complex nonequilibrium flows.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42302055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Particle-size dependent stability of co-continuous polymer blends 共连续聚合物共混物的粒度稳定性

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-06-08 DOI: 10.1122/8.0000642

Rajas Sudhir Shah, S. Bryant, M. Trifkovic

{"title":"Particle-size dependent stability of co-continuous polymer blends","authors":"Rajas Sudhir Shah, S. Bryant, M. Trifkovic","doi":"10.1122/8.0000642","DOIUrl":"https://doi.org/10.1122/8.0000642","url":null,"abstract":"The properties of polymer blend nanocomposites are typically associated with spatiotemporal distribution of nanoparticles within a polymer blend system. Here, we present in situ high-temperature confocal rheology studies to assess the effect of particle size on the extent of particle agglomeration, particle migration, and subsequently their influence on the coarsening dynamics of polymer blends filled with pristine silica particles. We investigate co-continuous polypropylene-poly(ethylene-co-vinyl acetate) blends filled with five different silica particles with a diameter ranging from 5 to 490 nm. While particle size does not play a role when particles are thermodynamically driven to their preferred polymer phase, a striking effect is achieved when particles are kinetically trapped at the interface. We find that the interparticle interaction largely driven by size dependent long-range repulsive forces governs their extent of agglomeration, severely affecting their ability to stabilize co-continuous morphology. Strikingly, the largest (490 nm) particles are more effective in suppressing coarsening than 5 nm particles, while 140 and 250 nm particles are found to be the most effective. We demonstrate that kinetic trapping of primary particles of either size is influenced by the interplay of interfacial folding during melt blending and Laplacian pressure exerted at the interface. These results extend our fundamental understanding of the stabilization of co-continuous morphology in polymer blends by particles.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45022451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nonequilibrium thermodynamics modeling of the rheological response of cement pastes 水泥浆体流变响应的非平衡热力学模型

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-06-02 DOI: 10.1122/8.0000643

Amalia K. Ioannou, Pavlos S. Stephanou

{"title":"Nonequilibrium thermodynamics modeling of the rheological response of cement pastes","authors":"Amalia K. Ioannou, Pavlos S. Stephanou","doi":"10.1122/8.0000643","DOIUrl":"https://doi.org/10.1122/8.0000643","url":null,"abstract":"Undoubtedly, cement is one of the most important materials in the construction industry. For its effective use, it is particularly important to fully comprehend the rheological behavior of cement paste. When cement is mixed with water, a suspension is initially formed and the rate of hydrolysis reactions accelerates leading to the formation of a new irreversible structure, i.e., the cement paste gradually solidifies. At the same time, the viscosity of the paste initially decreases with time, while at long times it gradually increases due to the formation of the irreversible structure. We herein introduce a continuum model for predicting the rheological behavior of cement pastes. The model is developed using nonequilibrium thermodynamics, in particular, the Generalized Brackets formalism, to guarantee model admissibility with thermodynamic laws. To this end, we consider two scalar structural variables: a reversible, λrev, characterizing the reversible structure, and an irreversible one, λirr, characterizing the irreversible structure resulting from the hydrolysis reactions. Also, we consider a tensorial structural variable, the conformation tensor c, to characterize the deformation of the cement particles. The predictions of the new model compare reasonably well with available experimental data, especially at large times, and further highlight the capacity of the new model to address the thixotropic behavior of cement pastes. It is expected that the use of this model in concrete rheology simulators will allow for the in silico testing and tailor-designing of concrete to meet specific processing needs.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":"1 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41491937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Magnetorheology in unsteady fields: From uniaxial DC to rotating AC fields 非定常场中的磁流变：从单轴直流场到旋转交流场

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-26 DOI: 10.1122/8.0000646

M. Terkel, Rosalind J Wright, J. D. de Vicente

引用次数: 0

Particle Image micro-Rheology (PIR) using displacement probability density function 基于位移概率密度函数的颗粒图像微流变学(PIR)

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-24 DOI: 10.1122/8.0000629

Adib Ahmadzadegan, H. Mitra, P. Vlachos, A. Ardekani

{"title":"Particle Image micro-Rheology (PIR) using displacement probability density function","authors":"Adib Ahmadzadegan, H. Mitra, P. Vlachos, A. Ardekani","doi":"10.1122/8.0000629","DOIUrl":"https://doi.org/10.1122/8.0000629","url":null,"abstract":"We present a novel approach to perform passive microrheology. A method to measure the rheological properties of fluids from the Brownian motion of suspended particles. Rheological properties are found from the particles' mean square displacements (MSDs) as a function of measurement time lag. Current state-of-the-art approaches find the MSD by tracking multiple particles' trajectories. However, particle tracking approaches face many limitations, including low accuracy and high computational cost, and they are only applicable to low particle seeding densities. Here, we present a novel method, termed particle image rheometry (PIR), for estimating the particle ensemble MSD from the temporal evolution of the probability density function of the displacement as a function of measurement time lag. First, the probability density function (PDF) of the particle displacements for each time lag is found using a generalized ensemble image cross-correlation approach that eliminates the need for particle tracking. Then, PDFs are used to calculate the MSD from which the complex viscosity of the solution is measured. We evaluate the performance of PIR using synthetic datasets and show that it can achieve an error of less than 1% in passive microrheology measurements, which corresponds to a twofold lower error than existing methods. Finally, we compare the measured complex viscosity from PIR with bulk rheometry for a polymeric solution and show agreement between the two measurements.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41703919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Rheological signatures of a glass-glass transition in an aging colloidal clay 老化胶体粘土中玻璃-玻璃转变的流变特征

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-09 DOI: 10.1122/8.0000592

R. Angelini, D. Larobina, B. Ruzicka, F. Greco, R. Pastore

{"title":"Rheological signatures of a glass-glass transition in an aging colloidal clay","authors":"R. Angelini, D. Larobina, B. Ruzicka, F. Greco, R. Pastore","doi":"10.1122/8.0000592","DOIUrl":"https://doi.org/10.1122/8.0000592","url":null,"abstract":"The occurrence of non-equilibrium transitions between arrested states has recently emerged as an intriguing issue in the field of soft glassy materials. The existence of one such transition has been suggested for aging colloidal clays (Laponite® suspensions) at a weight concentration of 3.0%, although further experimental evidences are necessary to validate this scenario. Here, we test the occurrence of this transition for spontaneously aged (non-rejuvenated) samples by exploiting the rheological tools of dynamical mechanical analysis. On imposing consecutive compression cycles to differently aged clay suspensions, we find that quite an abrupt change of rheological parameters occurs for ages around three days. For Young’s and elastic moduli, the change with the waiting time is essentially independent from the deformation rate, whereas other “fluid-like” properties, such as the loss modulus, do clearly display some rate dependence. We also show that the crossover identified by rheology coincides with deviations of the relaxation time (obtained through x-ray photon correlation spectroscopy) from its expected monotonic increase with aging. Thus, our results robustly support the existence of a glass-glass transition in aging colloidal clays, highlighting characteristic features of their viscoelastic behavior.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44420073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the selection of rheological tests for the prediction of 3D printability 关于预测三维可打印性的流变试验的选择

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-08 DOI: 10.1122/8.0000612

Y. Liu, M. Hildner, Omkar Roy, William A. Van den Bogert, James H. Lorenz, Maude Desroches, K. Koppi, A. Shih, Ronald G. Larson

{"title":"On the selection of rheological tests for the prediction of 3D printability","authors":"Y. Liu, M. Hildner, Omkar Roy, William A. Van den Bogert, James H. Lorenz, Maude Desroches, K. Koppi, A. Shih, Ronald G. Larson","doi":"10.1122/8.0000612","DOIUrl":"https://doi.org/10.1122/8.0000612","url":null,"abstract":"Direct ink writing is used to print multiple polydimethylsiloxane (PDMS) mixtures with fumed silica or as a two-part commercial liquid silicone rubber (LSR) mixed with polyethylene glycol (PEG) or as a two-part commercial vulcanizing (RTV) silicone. We correlate their printability into a hollow slump cone with rheological measurements, including (1) a shear rate up-ramp followed by (2) a down-ramp in the shear rate, (3) creep tests, and (4) large-amplitude oscillatory shear (LAOS) with increasing amplitude. The PDMS-fumed silica mixtures fail to print even at the highest fumed silica loading used (9 wt. %), while LSR-PEG with 4 or 6 wt. % PEG prints well, and one of the two RTV silicone components is printable, as is the mixture due in part to its rapid chemical curing. The large differences in printability of these materials do not correlate well with any single rheological test. They do correlate with a combination of a measure of material strength, given by either the yield stress σycr from creep tests or the “flow stress” σf at which G′ and G″ cross-over in LAOS, and of material recoverability given by the dynamic yield stress σy− in test 2. The latter is measured during a down-ramp in the shear rate after reaching a maximum shear rate of 1000 s−1, the highest shear rate in the print nozzle.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43588654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Effect of specific surface area on the rheological properties of graphene nanoplatelet/poly(ethylene oxide) composites 比表面积对石墨烯纳米片/聚环氧乙烷复合材料流变性能的影响

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-01 DOI: 10.1122/8.0000531

Haritha Haridas, M. Kontopoulou

{"title":"Effect of specific surface area on the rheological properties of graphene nanoplatelet/poly(ethylene oxide) composites","authors":"Haritha Haridas, M. Kontopoulou","doi":"10.1122/8.0000531","DOIUrl":"https://doi.org/10.1122/8.0000531","url":null,"abstract":"The rheological properties of poly(ethylene oxide) containing graphene nanoplatelets (GNPs) having different specific surface areas (SSAs) are studied using steady shear and small amplitude oscillatory shear experiments. A series of GNPs having SSAs ranging from 175 ± 5 to 430 ± 13 m2/g was prepared using a thermomechanical exfoliation process. The complex viscosity, moduli, and yield stress of the composites increase with SSA, whereas electrical and rheological percolation threshold concentrations decrease, suggesting that higher SSAs promote filler network formation. Modeling of small amplitude oscillatory shear data using a two-phase model confirms that hydrodynamic effects dominate at low concentrations below 8 wt. %, where the particles are noninteracting. At higher concentrations, the response is dominated by filler-phase contributions. We demonstrate that the two-phase model parameters can be used to track the exfoliation of graphite into GNPs. Fitting of rheological percolation curves using Utracki and Lyngaae–Jørgensen models at low concentrations (noninteracting regime) resulted in aspect ratios between 19 and 76. At high concentrations (interacting particles), the aspect ratios determined by the Krieger–Daugherty model ranged between 5 and 24 due to aggregation. The highest aspect ratios (defined as the ratio of major dimension to minor dimension) were associated with GNPs that had the highest SSA of 430 m2/g. Strain sweeps revealed that the critical strain for the onset of nonlinear viscoelasticity scaled with SSA above the percolation threshold. The scaling relationships of the critical strain and storage modulus with volume fraction were used to infer the fractal dimensions of filler networks.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47432831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Shear rheology of a dilute suspension of thin rings 薄环稀悬浮液的剪切流变学

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-01 DOI: 10.1122/8.0000628

Neeraj S. Borker, D. Koch

{"title":"Shear rheology of a dilute suspension of thin rings","authors":"Neeraj S. Borker, D. Koch","doi":"10.1122/8.0000628","DOIUrl":"https://doi.org/10.1122/8.0000628","url":null,"abstract":"The rheology of suspensions of rings (tori) rotating in an unbounded low Reynolds number simple shear flow is calculated using numerical simulations at dilute particle number densities [Formula: see text]. Suspensions of non-Brownian rings are studied by computing pair interactions that include hydrodynamic interactions modeled using slender body theory and particle collisions modeled using a short-range repulsive force. Particle contact and hydrodynamic interactions were found to have comparable influences on the steady-state Jeffery orbit distribution. The average tilt of the ring away from the flow-vorticity plane increased during pairwise interactions compared to the tilt associated with Jeffery rotation and the steady-state orbit distribution. Particle stresses associated with the increased tilt during the interaction were found to be comparable to the stresses induced directly by particle contact forces and the hydrodynamic velocity disturbances of other particles. The hydrodynamic diffusivity coefficients in the gradient and vorticity directions were also obtained and were found to be two orders of magnitude larger than the corresponding values in fiber suspensions at the same particle concentrations. Rotary Brownian dynamics simulations of isolated Brownian rings were used to understand the shear rate dependence of suspension rheology. The orbit distribution observed in the regime of weak Brownian motion, [Formula: see text], was surprisingly similar to that obtained from pairwise interaction calculations of non-Brownian rings. Here, the Peclet number [Formula: see text] is the ratio of the shear rate and the rotary diffusivity of the particle and [Formula: see text] is the effective inverse-aspect ratio of the particle (approximately equal to [Formula: see text] times the inverse of its non-dimensional Jeffery time period). Thus, the rheology results obtained from pairwise interactions should retain accuracy even for weakly Brownian rings [Formula: see text].","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47676407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Traversing with quantitative fidelity through the glass transition of amorphous polymers: Modeling the thermodynamic dilatational flow of polycarbonate 无定形聚合物玻璃化转变的定量保真遍历：聚碳酸酯热力学膨胀流的建模

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-05-01 DOI: 10.1122/8.0000607

M. Negahban, Wenlong Li, J. Saiter, L. Delbreilh, K. Strabala, Z. Li

引用次数: 0