Molecular simulation study of the glass transition for a flexible model of linear alkanes

Mariana Martin-Betancourt (1) , Jose Manuel Romero-Enrique (2) , Luis F. Rull (1)

1 Fisica Atomica, Molecular y Nuclear
2 Departamento de Física Atómica, Molecular y Nuclear

We present a Molecular Dynamics study in the isothermal-isobaric ensemble of a flexible model of linear n-alkanes for 2≤n ≤10 close to the glass transition. Our model is a modification of a realistic force field in which we have turned off the bond bending and the torsional intramolecular potentials to get the chain flexible. The glass transition is characterized by the change of slope of specific volume, as well as the vanishing of the self-diffusion coefficient and the divergence of the shear viscosity. Additionally we characterize the chain rearrangement dynamics above and close the glass transition. Our results are in qualitative agreement with those previously obtained with more realistic models, so we conclude that the flexibility of the alkane chain does not play a dominant role in the glass transition.

Mots clés: Physical Sciences

Mariana Martin-Betancourt, Jose Manuel Romero-Enrique, Luis F. Rull. Molecular simulation study of the glass transition for a flexible model of linear alkanes. Molecular Simulation, 2009, 35 (12-13), pp.1043-1050. ⟨10.1080/08927020902902767⟩. ⟨hal-00530451⟩