jz2013209_si_001.pdf (661.63 kB)
Alkyl Chain Length and Temperature Effects on Structural Properties of Pyrrolidinium-Based Ionic Liquids: A Combined Atomistic Simulation and Small-Angle X-ray Scattering Study
journal contribution
posted on 2015-12-16, 20:38 authored by Song Li, José Leobardo Bañuelos, Jianchang Guo, Lawrence Anovitz, Gernot Rother, Robert W. Shaw, Patrick C. Hillesheim, Sheng Dai, Gary A. Baker, Peter T. CummingsMolecular dynamics (MD) simulations of 1-alkyl-1-methylpyrrolidinium
bis(trifluoromethanesulfonyl)imide ([CnMPy][Tf2N], n = 3, 4, 6, 8, 10) were
conducted using an all-atom model. Radial distribution functions (RDF)
were computed and structure functions were generated to compare with
new X-ray scattering experimental results, reported herein. The scattering
peaks in the structure functions generally shift to lower Q values with increased temperature for all the liquids
in this series. However, the first sharp diffraction peak (FSDP) in
the longer alkyl chain liquids displays a marked shift to higher Q values with increasing temperature. Alkyl chain-dependent
ordering of the polar groups and increased tail aggregation with increasing
alkyl chain length were observed in the partial pair correlation functions
and the structure functions. The reasons for the observed alkyl chain-dependent
phenomena and temperature effects were explored.