8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P8.40Thu 811:10-14:00Computer simulation study of ionic liquids near the glasstransitionAlvaro Rodriguez-Rivas, 1 Jose Manuel Romero-Enrique, 1 and Luis F. Rull 11 Universidad de Sevilla, Dept. de Fisica Atomica, Molecular y Nuclear, Avenida ReinaMercedes s/n 41012, Sevilla, SpainWe present an NPT Molecular Dynamics computer simulation study of a simple model of supercooledionic liquids near the glass transition. The ionic liquid is modelled in the followingway: anions are considered as spherical charged soft spheres, and the cations like completely flexiblechains of tangent soft spheres, with a positive charge placed at the center of one of the endmonomers. In this study we have considered chains of length up to 5 monomers. We have monitoredthe approach to the glass transition by different transport properties such as self-diffusionand viscosity coefficients, as well as different time correlation functions and related functionssuch as the dynamic susceptibility and the non-gaussian parameter. We observe a high associationbetween the charged monomers, and some degree of segregation between charged and neutralmonomers. At a given pressure and temperature, the relaxation times decrease when increasingthe chain length, indicating a reduction of the glass transition temperature at a given pressure. Theresults of the viscosity coefficient suggest that ionic liquids are fragile glass generators.40