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Liang J, Yang D, Xiao Y, Chen S, Dadap JI, Rottler J, Ye Z. Shear Strain-Induced Two-Dimensional Slip Avalanches in Rhombohedral MoS 2. Nano Lett 2023; 23:7228-7235. [PMID: 37358360 DOI: 10.1021/acs.nanolett.3c01487] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Slip avalanches are ubiquitous phenomena occurring in three-dimensional materials under shear strain, and their study contributes immensely to our understanding of plastic deformation, fragmentation, and earthquakes. So far, little is known about the role of shear strain in two-dimensional (2D) materials. Here we show some evidence of 2D slip avalanches in exfoliated rhombohedral MoS2, triggered by shear strain near the threshold level. Utilizing interfacial polarization in 3R-MoS2, we directly probe the stacking order in multilayer flakes and discover a wide variety of polarization domains with sizes following a power-law distribution. These findings suggest that slip avalanches can occur during the exfoliation of 2D materials, and the stacking orders can be changed via shear strain. Our observation has far-reaching implications for the development of new materials and technologies, where precise control over the atomic structure of these materials is essential for optimizing their properties as well as for our understanding of fundamental physical phenomena.
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Affiliation(s)
- Jing Liang
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Dongyang Yang
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Yunhuan Xiao
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Sean Chen
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jerry I Dadap
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Joerg Rottler
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Ziliang Ye
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
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Steffen D, Schneider L, Müller M, Rottler J. Molecular simulations and hydrodynamic theory of nonlocal shear stresscorrelations in supercooled fluids. J Chem Phys 2022; 157:064501. [DOI: 10.1063/5.0098265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A supercooled fluid close to the glass transition develops nonlocal shear stress correlations that anticipate the emergence of elasticity. We performed molecular dynamics simulations of a binary Lennard-Jones mixture at different temperatures and investigated the spatiotemporal autocorrelation function of the shear stressfor different wavevectors, q, from a locally measured and Fourier-transformed stress tensor. Anisotropic correlations are observed at non-zero wavevectors, exhibiting strongly damped oscillations with a characteristic frequency ω(q). A comparison with a recently developed hydrodynamic theory [Maier et al., Phys. Rev. Lett. 119, 265701 (2017)] shows a remarkably good quantitative agreement between the particle-based simulations and the theoretical predictions.
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Affiliation(s)
- David Steffen
- Georg-August-Universität Göttingen Institut für Theoretische Physik, Germany
| | - Ludwig Schneider
- Institute for Theoretical Physics, Georg-August-Universität Göttingen Fakultät für Physik, Germany
| | - Marcus Müller
- Institute for Theoretical Physics, Georg August University Gottingen Faculty of Physics, Germany
| | - Joerg Rottler
- Department of Physics and Astronomy, University of British Columbia, Canada
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Fujimoto D, MacFarlane WA, Rottler J. Energy barriers and cooperative motion at the surface of freestanding glassy polystyrene films. J Chem Phys 2020; 153:154901. [PMID: 33092352 DOI: 10.1063/5.0022958] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigate the near-surface relaxation of freestanding atactic polystyrene films with molecular dynamics simulations. As in previous coarse-grained simulations, relaxation times for backbone segments and phenyl rings are linked to their bulk relaxation times via a power-law coupling relation. Variation of the coupling exponent with distance from the surface is consistent with depth-dependent activation barriers. We also quantify a reduction in dynamical heterogeneity at the interface, which can be interpreted in the framework of cooperative models for glassy dynamics.
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Affiliation(s)
- D Fujimoto
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - W A MacFarlane
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - J Rottler
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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Jabbari-Farouji S, Lame O, Perez M, Rottler J, Barrat JL. Role of the Intercrystalline Tie Chains Network in the Mechanical Response of Semicrystalline Polymers. Phys Rev Lett 2017; 118:217802. [PMID: 28598647 DOI: 10.1103/physrevlett.118.217802] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Indexed: 06/07/2023]
Abstract
We examine the microscopic origin of the tensile response in semicrystalline polymers by performing large-scale molecular dynamics simulations of various chain lengths. We investigate the microscopic rearrangements of the polymers during tensile deformation and show that the intercrystalline chain connections known as tie chains contribute significantly to the elastic and plastic response. These results suggest that the mechanical behavior of semicrystalline polymers is controlled by two interpenetrated networks of entanglements and tie chains.
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Affiliation(s)
- Sara Jabbari-Farouji
- Institute of Physics, Johannes Gutenberg-University, Staudingerweg 7-9, 55128 Mainz, Germany
| | - Olivier Lame
- Université de Lyon, INSA, MATEIS, UMR CNRS 5510, F69621 Villeurbanne, France
| | - Michel Perez
- Université de Lyon, INSA, MATEIS, UMR CNRS 5510, F69621 Villeurbanne, France
| | - Joerg Rottler
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada
| | - Jean-Louis Barrat
- Université Grenoble Alpes, LIPHY, F-38000 Grenoble, France and CNRS, LIPHY, F-38000 Grenoble, France
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Abstract
The onset of irreversible deformation in low-temperature amorphous solids is due to the accumulation of elementary events, consisting of spatially and temporally localized atomic rearrangements involving only a few tens of atoms. Recently, numerical and experimental work addressed the issue of spatiotemporal correlations between these plastic events. Here, we provide further insight into these correlations by investigating, via molecular dynamics (MD) simulations, the plastic response of a two-dimensional amorphous solid to artificially triggered local shear transformations. We show that while the plastic response is virtually absent in as-quenched configurations, it becomes apparent if a shear strain was previously imposed on the system. Plastic response has a fourfold symmetry, which is characteristic of the shear stress redistribution following the local transformation. At high shear rate we report evidence for a fluctuation-dissipation relation, connecting plastic response and correlation, which seems to break down if lower shear rates are considered.
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Affiliation(s)
- F Puosi
- Université Grenoble Alpes, LIPHY, F-38000 Grenoble, France.,CNRS, LIPHY, F-38000 Grenoble, France
| | - J Rottler
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada
| | - J-L Barrat
- Université Grenoble Alpes, LIPHY, F-38000 Grenoble, France.,CNRS, LIPHY, F-38000 Grenoble, France.,Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, F-38042 Grenoble, France
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Jabbari-Farouji S, Rottler J, Lame O, Makke A, Perez M, Barrat JL. Correlation of structure and mechanical response in solid-like polymers. J Phys Condens Matter 2015; 27:194131. [PMID: 25923991 DOI: 10.1088/0953-8984/27/19/194131] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Employing large scale molecular dynamics simulations, we measure the uniaxial tensile response of amorphous and semicrystalline states of a coarse-grained PVA bead-spring model. The response beyond the elastic limit encompasses strain-softening and strain-hardening regimes. To understand the underlying mechanisms of plastic deformation, we analyse conformational and structural changes of polymers. In particular, we characterise the volume distribution of crystalline domains along the stress-strain curve. The strain-softening regime in semicrystalline samples is dominated by deformation of crystalline parts, while strain-hardening involves unfolding and alignment of chains in both amorphous and crystalline parts. Comparing the tensile response of semicrystalline and amorphous polymers, we find similar conformations of polymers for both systems in the strain-hardening regime.
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Cubuk ED, Schoenholz SS, Rieser JM, Malone BD, Rottler J, Durian DJ, Kaxiras E, Liu AJ. Identifying structural flow defects in disordered solids using machine-learning methods. Phys Rev Lett 2015; 114:108001. [PMID: 25815967 DOI: 10.1103/physrevlett.114.108001] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Indexed: 06/04/2023]
Abstract
We use machine-learning methods on local structure to identify flow defects-or particles susceptible to rearrangement-in jammed and glassy systems. We apply this method successfully to two very different systems: a two-dimensional experimental realization of a granular pillar under compression and a Lennard-Jones glass in both two and three dimensions above and below its glass transition temperature. We also identify characteristics of flow defects that differentiate them from the rest of the sample. Our results show it is possible to discern subtle structural features responsible for heterogeneous dynamics observed across a broad range of disordered materials.
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Affiliation(s)
- E D Cubuk
- Department of Physics and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - S S Schoenholz
- Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - J M Rieser
- Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - B D Malone
- Department of Physics and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - J Rottler
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - D J Durian
- Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - E Kaxiras
- Department of Physics and School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - A J Liu
- Department of Physics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Jabbari-Farouji S, Rottler J, Lame O, Makke A, Perez M, Barrat JL. Plastic Deformation Mechanisms of Semicrystalline and Amorphous Polymers. ACS Macro Lett 2015; 4:147-150. [PMID: 35596422 DOI: 10.1021/mz500754b] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We use large-scale molecular dynamics simulations to investigate plastic deformation of semicrystalline polymers with randomly nucleated crystallites. The strain-softening regime is dominated by deformation of crystallites via reorientation of chain-folded lamellae toward the tensile axis, fragmentation of largest crystalline domains, and a partial loss of crystallinity. The strain-hardening regime coincides with unfolding of chains and recrystallization as a result of strain-induced chain alignment. These observed deformation mechanisms are consistent with experimental findings. We compare the tensile behavior of semicrystalline polymers with their amorphous counterparts at temperatures above and below the glass transition temperature.
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Affiliation(s)
| | - Joerg Rottler
- Department
of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada
| | - Olivier Lame
- INSA
Lyon, MATEIS, UMR CNRS 5510, Université de Lyon, F69621 Villeurbanne, France
| | - Ali Makke
- EPF école d'ingénieur, Institut Charles Delaunay, LASMIS UMR CNRS 6279, F10004 Troyes, France
| | - Michel Perez
- INSA
Lyon, MATEIS, UMR CNRS 5510, Université de Lyon, F69621 Villeurbanne, France
| | - Jean-Louis Barrat
- Université
Grenoble Alpes, UJF Liphy, F38041 Grenoble, France
- Institut Laue-Langevin, 6 rue
Jules Horowitz, BP 156, F-38042 Grenoble, France
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Puosi F, Rottler J, Barrat JL. Time-dependent elastic response to a local shear transformation in amorphous solids. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 89:042302. [PMID: 24827246 DOI: 10.1103/physreve.89.042302] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Indexed: 06/03/2023]
Abstract
The elastic response of a two-dimensional amorphous solid to induced local shear transformations, which mimic the elementary plastic events occurring in deformed glasses, is investigated via molecular-dynamics simulations. We show that for different spatial realizations of the transformation, despite relative fluctuations of order one, the long-time equilibrium response averages out to the prediction of the Eshelby inclusion problem for a continuum elastic medium. We characterize the effects of the underlying dynamics on the propagation of the elastic signal. A crossover from a propagative transmission in the case of weakly damped dynamics to a diffusive transmission for strong damping is evidenced. In the latter case, the full time-dependent elastic response is in agreement with the theoretical prediction, obtained by solving the diffusion equation for the displacement field in an elastic medium.
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Affiliation(s)
- F Puosi
- Université Grenoble 1/CNRS, LIPhy UMR 5588, Grenoble F-38041, France
| | - J Rottler
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia, Canada V6T 1Z4
| | - J-L Barrat
- Université Grenoble 1/CNRS, LIPhy UMR 5588, Grenoble F-38041, France and Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, F-38042 Grenoble, France
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Maier AKB, Huber KK, Klamann MKJ, Rottler J, Özlügedik S, Winterhalter S, Rosenbaum K, Joussen AM. Sekundärglaukom nach Keratoplastik: Risikofaktoren, Management und Ergebnisse. Klin Monbl Augenheilkd 2010. [DOI: 10.1055/s-0030-1270041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Morriss-Andrews A, Rottler J, Plotkin SS. A systematically coarse-grained model for DNA and its predictions for persistence length, stacking, twist, and chirality. J Chem Phys 2010; 132:035105. [PMID: 20095755 DOI: 10.1063/1.3269994] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We introduce a coarse-grained model of DNA with bases modeled as rigid-body ellipsoids to capture their anisotropic stereochemistry. Interaction potentials are all physicochemical and generated from all-atom simulation/parameterization with minimal phenomenology. Persistence length, degree of stacking, and twist are studied by molecular dynamics simulation as functions of temperature, salt concentration, sequence, interaction potential strength, and local position along the chain for both single- and double-stranded DNA where appropriate. The model of DNA shows several phase transitions and crossover regimes in addition to dehybridization, including unstacking, untwisting, and collapse, which affect mechanical properties such as rigidity and persistence length. The model also exhibits chirality with a stable right-handed and metastable left-handed helix.
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Affiliation(s)
- Alex Morriss-Andrews
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T1Z1, Canada
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Abstract
AIM The purpose of the study was to analyse the number of potential cornea donors in relationship to the number of actual donors. Furthermore, the reasons for the discrepancy between the number of the potential and actual donors were analysed. METHODS Over a period of 6 months data were collected from 6 hospitals and the institute for forensic medicine of the university hospital. The reasons why only a few actual donors from a big pool of potential donors remain for transplantation were investigated. RESULTS Circumstances related to the medical staff were causal for refusal in 37 % of the cases. In 23 % the cause for refusal was related to the relatives (23 %). Furthermore, in 16 organisational problems caused a failure in cornea donation. 18 % were excluded due to contraindications. A total rate of 6 % actual donors was achieved. CONCLUSIONS The final consent rate was only 6 % out of all potential donors. Organisational failure was only 16 % in contrast to 60 % refusal due to causes relating to medical staff and relatives. Therefore, further education of physicians and the public is needed.
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Affiliation(s)
- K Rosenbaum
- Augenklinik, Universitätsklinikum Düsseldorf, Düsseldorf, Germany
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Rottler J, Robbins MO. Yield conditions for deformation of amorphous polymer glasses. Phys Rev E Stat Nonlin Soft Matter Phys 2001; 64:051801. [PMID: 11735952 DOI: 10.1103/physreve.64.051801] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2001] [Indexed: 05/23/2023]
Abstract
Shear yielding of glassy polymers is usually described in terms of the pressure-dependent Tresca or von Mises yield criteria. We test these criteria against molecular dynamics simulations of deformation in amorphous polymer glasses under triaxial loading conditions that are difficult to realize in experiments. Difficulties and ambiguities in extending several standard definitions of the yield point to triaxial loads are described. Two definitions, the maximum and offset octahedral stresses, are then used to evaluate the yield stress for a wide range of model parameters. In all cases, the onset of shear is consistent with the pressure-modified von Mises criterion, and the pressure coefficient is nearly independent of many parameters. Under triaxial tensile loading, the mode of failure changes to cavitation, and the von Mises criterion no longer applies.
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Affiliation(s)
- J Rottler
- Department of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, USA
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Daya D, Demirev P, Eriksson J, Hallén A, Håkansson P, Johnson R, Kopniczky J, Papaléo R, Reimann C, Rottler J, Sundqvist B. Interaction of MEV atomic ions with molecular solids: Ion track structure and sputtering phenomena. RADIAT MEAS 1997. [DOI: 10.1016/s1350-4487(97)00048-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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