Accueil >
Production scientifique


(317) Production(s) de KOB W.

|
|
New optimization scheme to obtain interaction potentials for oxide glasses 
Auteur(s): Sundararaman Siddharth, Huang Liping, Ispas S., Kob W.
(Article) Publié:
The Journal Of Chemical Physics, vol. 148 p.194504 (2018)
Texte intégral en Openaccess : 
Ref HAL: hal-01806569_v1
DOI: 10.1063/1.5023707
WoS: 000432853800077
Exporter : BibTex | endNote
18 Citations
Résumé: We propose a new scheme to parameterize effective potentials that can be used to simulate atomic systems such as oxide glasses. As input data for the optimization, we use the radial distribution functions of the liquid and the vibrational density of state of the glass, both obtained from ab initio simulations, as well as experimental data on the pressure dependence of the density of the glass. For the case of silica, we find that this new scheme facilitates finding pair potentials that are significantly more accurate than the previous ones even if the functional form is the same, thus demonstrating that even simple two-body potentials can be superior to more complex three-body potentials. We have tested the new potential by calculating the pressure dependence of the elastic moduli and found a good agreement with the corresponding experimental data.
|

|
|
On the structure of liquids and glasses: More order than expected 
Auteur(s): Kob W.
Conférence invité: APS March meeting (Los Angeles, US, 2018-03-05)
|

|
|
Structure and Dynamics of a Polymer Nanocomposite 
Auteur(s): Sorichetti V., Hugouvieux Virginie, Kob W.
(Affiches/Poster)
Gordon Research Conference on Soft Condensed Matter Physics (Boston, US), 2017-08-13
|

|
|
Structuring polymer gels via catalytic reactions 
Auteur(s): Hugouvieux Virginie, Kob W.
(Article) Publié:
Soft Matter, vol. 13 p.8706-8716 (2017)
Texte intégral en Openaccess : 
Ref HAL: hal-01837825_v1
DOI: 10.1039/C7SM01814B
WoS: 000416556000005
Exporter : BibTex | endNote
2 Citations
Résumé: We use computer simulations to investigate how a catalytic reaction in a polymer sol can induce the formation of a polymer gel. To this aim we consider a solution of homopolymers in which freely-diffusing catalysts convert the originally repulsive A monomers into attractive B ones. We find that at low temperatures this reaction transforms the polymer solution into a physical gel that has a remarkably regular mesostructure in the form of a cluster phase, absent in the usual homopolymer gels obtained by a quench in temperature. We investigate how this microstructuring depends on catalyst concentration, temperature, and polymer density and show that the dynamics for its formation can be understood in a semi-quantitative manner using the interaction potentials between the particles as input. The structuring of the copolymers and the AB sequences resulting from the reactions can be discussed in the context of the phase behaviour of correlated random copolymers. The location of the spinodal line as found in our simulations is consistent with analytical predictions. Finally, we show that the observed structuring depends not only on the chemical distribution of the A and B monomers but also on the mode of formation of this distribution.
|

