Non-gaussian effects in the cage dynamics of polymers

Alistar Ottochian (1) , Cristiano de Michele (2) , Dino Leporini (3)

1 Fisica
2 Fisica
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The correlation between the fast cage dynamics and the structural relaxation is investigated in a model polymer system. It is shown that the cage vibration amplitude, as expressed by the Debye-Waller factor (DW), and the relaxation time τ_α collapse on a single universal curve with a simple analytic form when the temperature, the density, the chain length and the monomer-monomer interaction potential are changed. For the physical states with the same τ_α the coincidence of the mean-square displacement, the intermediate scattering function and the non-gaussian parameter is observed in a wide time window spanning from the ballistic regime to the onset of the Rouse dynamics driven by the chain connectivity. The role of the non-gaussian effects is discussed.

Mots clés: Physical Sciences

Alistar Ottochian, Cristiano de Michele, Dino Leporini. Non-gaussian effects in the cage dynamics of polymers. Philosophical Magazine, 2008, 88 (33-35), pp.4057-4062. ⟨10.1080/14786430802348060⟩. ⟨hal-00513945⟩