Development of Polarizable Forcefields For Ionic Liquids

Ionic liquids (ILs) are being considered as potential candidates for variety of applications, such as green propellants, solvents and biomedical applications. Therefore, there is a critical need to design novel ILs with desired properties. Simulation techniques, such as molecular dynamics, have the ability to predict bulk properties, such as viscosity, density and thermal conductivity, provided accurate forcefields are available. In this STTR, CFDRC, in collaboration with Washington University (St. Louis), aims at developing high-quality IL-specific forcefields for accurate prediction of bulk properties. Until now, there is no IL-specific forcefield, and existing simulations are based on modifying the CHARM or AMBER forcefields. In the proposed work, we plan to develop comprehensive polarizable forcefield for several ILs. The forcefield will be developed by extracting data from high level ab initio quantum chemistry calculations. The proposed forcefield advances the state-of-the-art polarization interaction by inclusion of quadrupoles moments in the interaction potential. The forcefields will then be used in the freely available TINKER molecular dynamics code of Washington University to compute bulk properties. Since intermolecular forcefields are critical for bulk property prediction, in Phase I, the intermolecular forcefield will be developed. In Phase II, a library of inter and intramolecular forcefields will be constructed that can simulate variety of ILs.