Journal of Rheology最新文献

Spreading ceramic stereolithography pastes: Insights from shear- and orthogonal-rheology 陶瓷立体光刻浆料的铺展：剪切流变学和正交流变学的启示

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-12-21 DOI: 10.1122/8.0000688

Sylvain Fournier, Jérôme Chevalier, Saray Pérez-Robles, C. Carotenuto, M. Minale, H. Reveron, G. Baeza

{"title":"Spreading ceramic stereolithography pastes: Insights from shear- and orthogonal-rheology","authors":"Sylvain Fournier, Jérôme Chevalier, Saray Pérez-Robles, C. Carotenuto, M. Minale, H. Reveron, G. Baeza","doi":"10.1122/8.0000688","DOIUrl":"https://doi.org/10.1122/8.0000688","url":null,"abstract":"We study the shear rheological behavior of a commercial stereolithography paste containing ≈50 vol. % of zirconia particles (diameter ≈ 100 nm) with the aim to clarify physical mechanisms occurring during the “scraping” step of this yield stress fluid. Beyond a flow curve characterized by a high zero-shear viscosity accompanied with an overall shear-thinning behavior, we investigate in a systematic way the transient regime through start-up experiments. We demonstrate that a structural transition occurs between 10−2 and 10−1 s−1, resulting in an apparent interruption of the shear-thinning. The corresponding transient response presents a pronounced extra-growth of the shear stress before to stabilize at high strain amplitude and a negative first normal stress difference peak, both effects become stronger at higher shear rates. These observations are rationalized based on the high interparticle friction owing to the polyhedral shape and the roughness of the particles. In addition, relaxation tests following the start-up experiments reveal that the samples submitted to shear rates higher than 10−1 s−1 cannot relax the shear stress to the same level as in low shear rate experiments, suggesting a durable structural modification likely to impact the quality of the parts prior to their debinding and densification. Finally, we utilize orthogonal superposition rheology to illustrate how the application of an oscillatory deformation during the scraping procedure could help to reduce the shear-thinning interruption and improve the stereolithography processing as already observed empirically during scraping.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":"12 5","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138949235","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

Molecular dynamics simulation of mechanical relaxation of poly(propyleneimine) dendrimers 聚丙烯酰亚胺树枝状聚合物机械松弛的分子动力学模拟

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-12-20 DOI: 10.1122/8.0000723

N. Sheveleva, A. Komolkin, D. Markelov

{"title":"Molecular dynamics simulation of mechanical relaxation of poly(propyleneimine) dendrimers","authors":"N. Sheveleva, A. Komolkin, D. Markelov","doi":"10.1122/8.0000723","DOIUrl":"https://doi.org/10.1122/8.0000723","url":null,"abstract":"We report on shear-stress relaxation of melts of poly(propyleneimine) (PPI) dendrimers of different generations (G2–G5). The aim of this study was to confirm our previous conclusion in Sheveleva et al. [Phys. Chem. Chem. Phys. 24, 13049–13056 (2022)] for carbosilane dendrimers that an impenetrable inner region leads to the manifestation of the crowded environment effect. The systems of PPI dendrimer melts are studied using atomistic molecular dynamics simulations. The time and frequency dependencies of the dynamic shear-stress modulus are investigated. The results are in good agreement with the available rheological experimental data for G2–G4 PPI. We have found that the crowded environment effect does not manifest itself in the mechanical relaxation of G4 PPI dendrimers in contrast to G4 carbosilane dendrimers. Despite their similar topology and close sizes, G4 PPI does not form an impenetrable core. The G5 PPI dendrimer has an impenetrable inner region, and the crowded environment effect is observed. As in carbosilane dendrimers, the maximal time of mechanical relaxation is increased due to the crowded environment effect. However, the opposite situation is for the rotational diffusion of the G5 PPI dendrimers. In contrast to carbosilane dendrimers, the rotational mobility of G5 PPI significantly slows down even taking into account the increase in the dendrimer size. The hydrogen bonding between PPI dendrimers affects the mechanical relaxation at high frequencies (short times) and enhances with growing G.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":"78 5","pages":""},"PeriodicalIF":3.3,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138957830","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

Shear-induced crystallization of polypropylene/low-density polyethylene blend 聚丙烯/低密度聚乙烯混合物的剪切诱导结晶

IF 3.3 2区工程技术

Journal of Rheology Pub Date : 2023-12-18 DOI: 10.1122/8.0000742

Khunanya Janchai, Masayuki Yamaguchi

引用次数: 0

Beauty Inside Out: Examining Beauty Product Use Among Diverse Women and Femme-Identifying Individuals in Northern Manhattan and South Bronx Through an Environmental Justice Framework. 由内而外的美丽：通过环境正义框架考察曼哈顿北部和南布朗克斯地区不同女性和女性身份认同者使用美容产品的情况。

IF 2 2区工程技术

Journal of Rheology Pub Date : 2023-12-01 Epub Date: 2023-11-30 DOI: 10.1089/env.2022.0053

Lariah Edwards, Lubna Ahmed, Leslie Martinez, Sophia Huda, Bhavna Shamasunder, Jasmine A McDonald, Robert Dubrow, Beaumont Morton, Ami R Zota

{"title":"Beauty Inside Out: Examining Beauty Product Use Among Diverse Women and Femme-Identifying Individuals in Northern Manhattan and South Bronx Through an Environmental Justice Framework.","authors":"Lariah Edwards, Lubna Ahmed, Leslie Martinez, Sophia Huda, Bhavna Shamasunder, Jasmine A McDonald, Robert Dubrow, Beaumont Morton, Ami R Zota","doi":"10.1089/env.2022.0053","DOIUrl":"10.1089/env.2022.0053","url":null,"abstract":"<p><p>The disproportionate use of chemical straighteners and skin lighteners by women of color is a growing public health concern given the link between product use and adverse health effects. Prior studies examined product use as an individual choice but neglected social-structural factors, which influence beauty perceptions and personal decisions around product use. We used a community-based participatory research approach to characterize product use by demographics and investigated how racialized beauty norms impact use among 297 women and femme-identifying individuals in Northern Manhattan and the South Bronx. Product use varied by race/ethnicity, nativity, and messaging from family and peers. Black respondents were more likely to ever use chemical straighteners than non-Black respondents (OR = 2.0; 95% CI = 1.2-3.2), as were respondents who heard that family members express a preference for straight hair compared with respondents whose family members expressed mixed preferences about hairstyles (OR = 2.0; 95% CI = 1.1-3.7). Compared with non-Asian respondents and respondents born in the United States, Asian respondents and respondents born in other countries, respectively, had threefold higher odds of ever using skin lighteners (Asian: OR = 3.2; 95% CI = 1.4-7.0; born in other countries: OR = 3.4; 95% CI = 1.9-6.1). Respondents' perceptions that others believe straight hair or lighter skin confer benefits such as beauty, professionalism, or youth were associated with greater use of chemical straighteners and skin lighteners. These findings highlight the pervasiveness of racialized beauty norms and point to the need to reduce the demand for and sale of these products through community education, market-based strategies, and public policy.</p>","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":"34 1","pages":"449-460"},"PeriodicalIF":2.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10704575/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85700443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fiber spinning from polymer solutions 用聚合物溶液纺丝

2区工程技术

Journal of Rheology Pub Date : 2023-11-01 DOI: 10.1122/8.0000726

Ralph H. Colby

引用次数: 0

Characterization of the temperature and frequency dependency of the complex Poisson’s ratio using a novel combined torsional-axial rheometer 用一种新型扭轴复合流变仪表征复泊松比的温度和频率依赖性

2区工程技术

Journal of Rheology Pub Date : 2023-11-01 DOI: 10.1122/8.0000675

José Alberto Rodríguez Agudo, Jan Haeberle, Michael Müller-Pabel, Alexander Troiss, Abhishek Shetty, Joachim Kaschta, Christopher Giehl

{"title":"Characterization of the temperature and frequency dependency of the complex Poisson’s ratio using a novel combined torsional-axial rheometer","authors":"José Alberto Rodríguez Agudo, Jan Haeberle, Michael Müller-Pabel, Alexander Troiss, Abhishek Shetty, Joachim Kaschta, Christopher Giehl","doi":"10.1122/8.0000675","DOIUrl":"https://doi.org/10.1122/8.0000675","url":null,"abstract":"This study discusses the feasibility of using a combined torsional-axial rheometer to indirectly measure the complex Poisson’s ratio based on shear and Young’s modulus. For this purpose, isothermal frequency sweeps in torsion and extension are performed sequentially on the same cylindrical specimen and under the same environmental conditions. The method is tested on two amorphous polymers, a semicrystalline polymer, a polymer blend, and a copolymer. The article includes an extensive literature review and an uncertainty assessment of the method to provide a basis for subsequent data comparison with existing research. The experimental data show a monotonic increase in the complex Poisson’s ratio up to 0.5 as the temperature approaches α-relaxation for all samples, except for the amorphous polymer. The latter shows a local minimum in the complex Poisson’s ratio observed near α-relaxation, which disappears after thermal annealing of the sample above the α-relaxation temperature. The real and imaginary parts of the complex Poisson’s ratio are additionally determined by evaluating both phase shift angles from torsional and extensional measurements. All polymers show a certain offset between the torsional and extensional phase shift angles in the glassy state, which gradually decreases as the temperature approaches α-relaxation. The complex Poisson’s ratio results are in good agreement with the literature data obtained by existing methods. This confirms that the method is applicable to polymers up to α-relaxation temperatures with significant time savings due to the nondestructive approach. This is of particular interest, given the limited availability of data in the literature.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":"34 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372176","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

Thixotropy, antithixotropy, and viscoelasticity in hysteresis 触变性、反触变性和滞回中的粘弹性

2区工程技术

Journal of Rheology Pub Date : 2023-10-31 DOI: 10.1122/8.0000620

Yilin Wang, Randy H. Ewoldt

{"title":"Thixotropy, antithixotropy, and viscoelasticity in hysteresis","authors":"Yilin Wang, Randy H. Ewoldt","doi":"10.1122/8.0000620","DOIUrl":"https://doi.org/10.1122/8.0000620","url":null,"abstract":"Thixotropy, antithixotropy, and viscoelasticity are three types of time-dependent dynamics that involve fundamentally different underlying physical processes. Here, we show that the three dynamics exhibit different signatures in hysteresis by examining the fingerprints of the simplest thixotropic kinetic model, a new antithixotropic model that we introduce here, and the Giesekus model. We start by showing that a consistent protocol to generate hysteresis loops is a discrete shear-rate controlled ramp that begins and ends at high shear rates, rather than at low shear rates. Using this protocol, we identify two distinguishing features in the resulting stress versus shear rate loops. The first is the direction of the hysteresis loops: clockwise for thixotropy, but counterclockwise for viscoelasticity and antithixotropy. A second feature is achieved at high ramping rates where all responses lose hysteresis: the viscoelastic response shows a stress plateau at low shear rates due to lack of stress relaxation, whereas the thixotropic and antithixotropic responses are purely viscous with minimal shear thinning or thickening. We establish further evidence for these signatures by experimentally measuring the hysteresis of Laponite suspensions, carbon black suspensions, and poly(ethylene oxide) solutions, each representing a historically accepted example of each class of material behavior. The signatures measured in experiments are consistent with those predicted by the three models. This study reveals different fingerprints in hysteresis loops associated with thixotropy, antithixotropy, and viscoelasticity, which may be helpful in distinguishing the three time-dependent responses.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":"23 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135870142","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

Universal scaling of shear thickening transitions 普遍缩放剪切增厚过渡

2区工程技术

Journal of Rheology Pub Date : 2023-10-05 DOI: 10.1122/8.0000697

Meera Ramaswamy, Itay Griniasty, Danilo B. Liarte, Abhishek Shetty, Eleni Katifori, Emanuela Del Gado, James P. Sethna, Bulbul Chakraborty, Itai Cohen

{"title":"Universal scaling of shear thickening transitions","authors":"Meera Ramaswamy, Itay Griniasty, Danilo B. Liarte, Abhishek Shetty, Eleni Katifori, Emanuela Del Gado, James P. Sethna, Bulbul Chakraborty, Itai Cohen","doi":"10.1122/8.0000697","DOIUrl":"https://doi.org/10.1122/8.0000697","url":null,"abstract":"Nearly, all dense suspensions undergo dramatic and abrupt thickening transitions in their flow behavior when sheared at high stresses. Such transitions occur when the dominant interactions between the suspended particles shift from hydrodynamic to frictional. Here, we interpret abrupt shear thickening as a precursor to a rigidity transition and give a complete theory of the viscosity in terms of a universal crossover scaling function from the frictionless jamming point to a rigidity transition associated with friction, anisotropy, and shear. Strikingly, we find experimentally that for two different systems—cornstarch in glycerol and silica spheres in glycerol—the viscosity can be collapsed onto a single universal curve over a wide range of stresses and volume fractions. The collapse reveals two separate scaling regimes due to a crossover between frictionless isotropic jamming and frictional shear jamming, with different critical exponents. The material-specific behavior due to the microscale particle interactions is incorporated into a scaling variable governing the proximity to shear jamming, that depends on both stress and volume fraction. This reformulation opens the door to importing the vast theoretical machinery developed to understand equilibrium critical phenomena to elucidate fundamental physical aspects of the shear thickening transition.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135481366","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: 7

The effect of instrument inertia on the initiation of oscillatory flow in stress controlled rheometry 应力控制流变法中仪器惯量对振荡流起始的影响

2区工程技术

Journal of Rheology Pub Date : 2023-10-04 DOI: 10.1122/8.0000665

Adeniyi Ogunkeye, Rebecca E. Hudson, Daniel J. Curtis

引用次数: 0

Viscosity experiments of slag-spinel suspensions: The effect of volume fraction, particle size, and shear rate 渣尖晶石悬浮液粘度实验:体积分数、粒度和剪切速率的影响

2区工程技术

Journal of Rheology Pub Date : 2023-10-04 DOI: 10.1122/8.0000690

Olivier Vergote, Inge Bellemans, Amy Van den Bulck, Maksym Shevchenko, Roman Starykh, Evgueni Jak, Kim Verbeken

{"title":"Viscosity experiments of slag-spinel suspensions: The effect of volume fraction, particle size, and shear rate","authors":"Olivier Vergote, Inge Bellemans, Amy Van den Bulck, Maksym Shevchenko, Roman Starykh, Evgueni Jak, Kim Verbeken","doi":"10.1122/8.0000690","DOIUrl":"https://doi.org/10.1122/8.0000690","url":null,"abstract":"Heterogeneous slag viscosity measurements have a wide variety of parameters, such as particle size, shape, solid volume fraction, and shear rate, which affect the final measured viscosity. Often, some of these parameters are neglected or predicted via models, since it is experimentally difficult to determine them during high-temperature slag viscosity measurements. In this work, a viscosity apparatus was used, which allows quenching of the sample after measurement. This way, all relevant parameters could be experimentally determined. The viscosities of three datasets were studied with various spinel sizes: small (13 μm), medium (34 μm), and large particles (76 μm). Within each dataset, the composition of the liquid slag matrix was kept constant to uniquely measure the effect of solids. Shear thinning, i.e., a decreasing viscosity with increasing shear rate, was observed for all samples, even at a low vol. % of 1.8. Moreover, stronger shear thinning was observed at a higher vol. % and for smaller spinel particles. On the basis of these results, the phenomenon of shear thinning was discussed and mainly attributed to the particle–particle orientation in the suspension. The obtained viscosity values were used to optimize a Krieger–Dougherty equation, which describes the viscosity increase caused by the presence of a certain vol. % of spinel particles, with a certain size and at a specific shear rate.","PeriodicalId":16991,"journal":{"name":"Journal of Rheology","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135590506","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