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| Type |
Poster Presentation |
| Area |
Physical Chemistry |
| Room No. |
Exhibition Hall 2+3 |
| Time |
10월 20일 (금요일) 13:00~14:30 |
| Code |
PHYS.P-96 |
| Subject |
Translation-Rotation Decoupling of Tracers of Locally Favorable Structures in Glass-Forming Liquids |
| Authors |
YoonJae Park, Bong June Sung*
Department of Chemistry, Sogang University, Korea
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| Abstract |
Liquids consist of regions of different mobility near the glass transition, which is called the dynamic heterogeneity. Particles in glass-forming liquids may form domains of locally favorable structures (LFS) upon supercooling. Whether and how the LFS domains would relate to the slow relaxation and dynamic heterogeneity of the glass-forming liquids have been issues of interest. According to the Stokes-Einstein (SE) relation and the Debye-Stokes-Einstein (DSE) relation, the ratio of the translational (DT) and rotational (DR) diffusion coefficients should be a constant over a range of temperatures. In supercooled liquids and glasses, however, DT and DR decouple due to dynamic heterogeneity, and DT/DR may not be constant any more. In this study, we employ tracers whose structures resemble the LFS domains in Wahnström and Kob-Andersen (KA) glass-forming liquids, and investigate the translation-rotation decoupling of the tracers. In Wahnström liquids, icosahedron LFS domains are the most long-lived ones and the mobility of neighbor particles is suppressed. We find from our simulations that the icosahedron tracers experience drastic translation-rotation decoupling upon cooling. In KA liquids, bicapped square antiprism LFS domains are the most long-lived ones, which are not correlated significantly with the local mobility. DT and DR of bicapped square antiprism tracers do not decouple significantly. The difference in the decoupling behavior between different types of tracers indicates that there should be the structural motif during in glasses. |
| E-mail |
dbswo9396@hanmail.net |
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120th General Meeting of the KCS