Real-space Dynamics in Aqueous Salt Solution
ORAL
Abstract
We report on the real-space correlated motion of water molecules and ions in an aqueous salt solution. The Van Hove functions–pair-correlation functions in space and time–of aqueous salt solution were determined by high-resolution inelastic X-ray scattering (IXS) spectra over a wide range of momentum transfer and energy transfer as well as molecular dynamics simulation. (Pseudo-) Partial Van Hove function was determined to disentangle the element-specific correlated motions. Our results directly depict the distance-dependent correlated dynamics of aqueous salt solutions in picosecond timescale and identify the changes in the anion–water and cation–water correlations. We found that the ion–water correlations show a two-step relaxation, which corresponds to a local rattling-like vibration and the local configurational rearrangement.
*Inelastic X-ray scattering work by Y.S. and T.E. was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials and Science and Engineering Division. High-energy X-ray diffraction work by C.W.R. and W.D. and MD simulation work by R.M., M.W.T., and P.T.C. were supported as part of the Fluid Interface Reactions, Structures and Transport (FIRST) Center, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.
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Presenters
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Yuya Shinohara
- Oak Ridge National Lab