Title: Computation of melting points, crystalline free energies, and transport properties of molten salts Speaker: Saivenkataraman Jayaraman, Notre Dame University (advisor Prof. Ed Maginn) Date/Time: Wednesday, January 14, 2009, 10:30 – 11:30 am Location: CSRI Building/Room 90 (Sandia-NM) Brief Abstract: Ionic liquids are salts which have melting points near ambient temperatures. They are finding application in separations, catalysis, and lubrication fields. Traditional ionic salt eutectic mixtures are being considered for use as industrial heat transfer fluids in solar power generation systems. Viscosity, thermal conductivity, density and melting point are some of the properties critical for the use of these salts in these heat transfer applications. Given the difficulties associated with experimental determination of these properties, particularly for high temperature systems, there is considerable interest in developing molecular modeling based computational approaches for predicting properties of molten salts. Melting point has been traditionally one of the most difficult properties to estimate from molecular simulations. Recently, we developed a newmethod in our group [1-2] which allows us to compute melting points accurately. In our recent study [3], we computed the melting points of the two known crystal polymorphs, an orthorhombic and a monoclinic structure, of the ionic liquid 1-n-butyl-3-methylimidazolium chloride. We also computed the free energy difference between the two structures, which leads to a new application of this method for the determination of relative stabilities of crystal polymorphs. This method is being applied to estimate the melting points of nitrate salts of lithium, sodium and potassium, mixtures of which are under consideration as candidates for use in solar energy applications. Molecular simulations are also being utilized for computing other properties such as viscosity and thermal conductivity. [1] D. M. Eike, J. F. Brennecke, and E. J. Maginn, J.Chem. Phys. 122, 014115 (2005). CSRI POC: Aidan Thompson (505) 844-9702 |