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

P1.10Fri 911:10-14:00Primary relaxation in 1-alkyl-3-methylimidazoliumbromide liquidsMiguel A. Gonzalez, 1 Bachir Aoun, 1 David Price, 2 Marie-Louise Saboungi, 3Wolfgang Haussler, 4 Alberto Rivera, 4 and Carlos Leon 51 Institut Laue-Langevin, 6 rue Jules Horowitz, 38042, Grenoble, France2 CEMHTI (CNRS), Orleans, France3 CRMD CNRS, Orleans, France4 FRM-II E-21, Technische Universitat Munchen, Garching, Germany5 GRMC, Dep. Fisica Aplicada III, CC. Fisicas UCM), Madrid, SpainDuring the last decade the interest in room temperature ionic liquids has literally exploded, as theirunique characteristics make of them potential candidates for a large number of applications. Inparticular they offer the possibility of tailoring their properties by modifying selectively the cationand/or the anion forming the liquid. We have explored the effect on the microscopic dynamics ofincreasing the length of the alkyl chain of the cation in a series of 1-alkyl-3-methylimidazoliumbromide ionic liquids (alkyl = ethyl, butyl, and hexyl). The temperature dependence of the structuralrelaxation has been investigated combining neutron scattering (backscattering and spin-echo)and dielectric relaxation measurements. Additionally we have performed MD simulations in orderto determine the nature of the primary as well as of the secondary relaxations observed experimentallyover a large range of frequencies.10