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Etude des propriétés structurales, électroniques et vibrationnelles des verres et des nanostructures par simulation ab-initio
(7) Production(s) de l'année 2023

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The two faces of friction in the relaxation dynamics of granular systems
Auteur(s): Kob W.
Conférence invité: Komaba Mini-Workshop (Tokyo, JP, 2023-08-22)
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Granular materials under cyclic shear: No elastic regime and they always flow
Auteur(s): Kob W.
Conférence invité: 9th International Discussion Meeting on Relaxation in Complex Systems (Chiba, JP, 2023-08-12)
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Surface properties of alkali silicate glasses: Influence of the modifiers 
Auteur(s): Zhang Z., Ispas S., Kob W.
(Article) Publié:
The Journal Of Chemical Physics, vol. 158 p.244504 (2023)
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On the medium-range order in silicate glass-formers: From standard two-body correlations to many-body correlations
Auteur(s): Kob W.
Conférence invité: 4th International Workshop on Challenges of MD simulations of Glasses and Amorphous Materials (Corning, US, 2023-07-13)
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Deformation and fracture of silicate glasses: New insights from atomistic simulations
Auteur(s): Kob W.
Conférence invité: GOMD 2023 (New Orleans, US, 2023-06-04)
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Structure and elasticity of model disordered, polydisperse, and defect-free polymer networks 
Auteur(s): Sorichetti V., Ninarello A. S., Ruiz-Franco José, Hugouvieux Virginie, Zaccarelli Emanuela, Micheletti Cristian, Kob W., Rovigatti Lorenzo
(Article) Publié:
The Journal Of Chemical Physics, vol. 158 p.074905 (2023)
Texte intégral en Openaccess : 
Ref HAL: hal-04043309_v1
Ref Arxiv: 2211.04810
DOI: 10.1063/5.0134271
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: The elasticity of disordered and polydisperse polymer networks is a fundamental problem of soft matter physics that is still open. Here, we self-assemble polymer networks via simulations of a mixture of bivalent and tri- or tetravalent patchy particles, which result in an exponential strand length distribution analogous to that of experimental randomly cross-linked systems. After assembly, the network connectivity and topology are frozen and the resulting system is characterized. We find that the fractal structure of the network depends on the number density at which the assembly has been carried out, but that systems with the same mean valence and same assembly density have the same structural properties. Moreover, we compute the long-time limit of the mean-squared displacement, also known as the (squared) localization length, of the cross-links and of the middle monomers of the strands, showing that the dynamics of long strands is well described by the tube model. Finally, we find a relation connecting these two localization lengths at high density and connect the cross-link localization length to the shear modulus of the system.
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Creating bulk ultrastable glasses by random particle bonding 
Auteur(s): Ozawa M., Iwashita Yasutaka, Kob W., Zamponi Francesco
(Article) Publié:
Nature Communications, vol. 14 p.113 (2023)
Texte intégral en Openaccess : 
Ref HAL: hal-03929003_v1
Ref Arxiv: 2203.14604
DOI: 10.1038/s41467-023-35812-w
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: Abstract A recent breakthrough in glass science has been the synthesis of ultrastable glasses via physical vapor deposition techniques. These samples display enhanced thermodynamic, kinetic and mechanical stability, with important implications for fundamental science and technological applications. However, the vapor deposition technique is limited to atomic, polymer and organic glass-formers and is only able to produce thin film samples. Here, we propose a novel approach to generate ultrastable glassy configurations in the bulk, via random particle bonding, and using computer simulations we show that this method does indeed allow for the production of ultrastable glasses. Our technique is in principle applicable to any molecular or soft matter system, such as colloidal particles with tunable bonding interactions, thus opening the way to the design of a large class of ultrastable glasses.
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