2024-03-29T11:28:09Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/74132008-10-02T14:37:14Zcom_10261_115com_10261_3col_10261_368
Atomic motions in the ab-merging region of 1,4-polybutadiene: A molecular dynamics simulation study
Narros, Arturo
Arbe, Arantxa
Álvarez González, Fernando
Colmenero de León, Juan
Richter, Dieter
Diffusion
Molecular dynamics method
Polymers
17 pp.-- PACS nrs.: 36.20.Ey, 36.20.Hb, 31.15.xv.
We present fully atomistic molecular dynamics simulations on 1,4-polybutadiene in a wide temperature range from 200 to 280 K, i.e., in the region where the α- and β-relaxations merge and above. A big computational effort has been performed —especially for the lowest temperatures investigated — to extend the simulation runs to very long times (up to 1 µs for 200 K). The simulated sample has been carefully validated by using previous neutron scattering data on the real sample with similar microstructure. Inspecting the trajectories of the different hydrogens in real space, we have observed a heterogeneous dynamical behavior (each kind of hydrogen moves in a different way) with signatures of combined hopping and diffusive motions in the whole range investigated. The application of a previously proposed model [Colmenero et al., Europhys. Lett. 71, 262 (2005)] is successful and a characterization of the local motions and diffusion is possible. The comparison of our results to those reported in the literature provides a consistent scenario for polybutadiene dynamics and puts into a context the different experimental observations. We also discuss the impact of the hopping processes on the observation and interpretation of experimentally accessible magnitudes and the origin of the deviations from Gaussian behavior in this system.
This research project has been supported by the European Commission NoE SoftComp, Contract No. NMP3-CT-2004-502235. A.A., F.A., and J.C. acknowledge support from Project Nos. MAT2007-63681 and IT-436-07 (G.V.) and the Spanish Ministerio de Educacion y Ciencia (Grant No. CSD2006-53). "Donostia International Physics Center" is also acknowledged. A.N. acknowledges the FPI grant of the Spanish Ministry of Science and Technology.
Peer reviewed
2008-10-02T14:36:33Z
2008-10-02T14:36:33Z
2008-06-11
artículo
http://purl.org/coar/resource_type/c_6501
Journal of Chemical Physics 128, 224905 (2008).
0021-9606
http://hdl.handle.net/10261/7413
10.1063/1.2937733
en
http://dx.doi.org/10.1063/1.2937733
none
533 bytes
text/plain
American Institute of Physics