The correlation between the fast cage dynamics and structural relaxation is investigated in a model polymer system. It is shown that the cage vibration amplitude, as expressed by the Debye-Waller factor, and the relaxation time tau(alpha) 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 tau(alpha) 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.
Non-Gaussian effects in the cage dynamics of polymers / A., Ottochian; DE MICHELE, Cristiano; D., Leporini. - In: PHILOSOPHICAL MAGAZINE. - ISSN 1478-6435. - STAMPA. - 88:33-35(2008), pp. 4057-4062. (Intervento presentato al convegno 11th International Workshop on Complex Systems tenutosi a Andalo, ITALY nel MAR 17-20, 2008) [10.1080/14786430802348060].
Non-Gaussian effects in the cage dynamics of polymers
DE MICHELE, CRISTIANO;
2008
Abstract
The correlation between the fast cage dynamics and structural relaxation is investigated in a model polymer system. It is shown that the cage vibration amplitude, as expressed by the Debye-Waller factor, and the relaxation time tau(alpha) 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 tau(alpha) 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
