Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Quasielastic Neutron Scattering Studies on Glass-Forming Ionic Liquids with Imidazolium Cations



Maiko Kofu, Madhu Sudan Tyagi, Yasuhiro Inamura, Kyoko Miyazaki, Osamu Yamamuro


Relaxation processes for imidazolium-based ionic liquids (ILs) were investigated by means of an incoherent quasiealstic neutron scattering technique. In order to clarify the cation and anion effects at around 1ps, 10 ps, and 100 ps-10 ns, each corresponding to the alkyl reorientation, the relaxation related to the imidazolium ring, and the ionic diffusion. The activation energy (Ea) for the alkyl relaxation is insensitive to both anion size decreases but is almost independent of the alkyl chain length. This indicates that the ionic diffusion and imidazolium relaxation are governed by the coulombic interaction between the core parts of the cations (imidazolium ring) and the anions. This is consistent with the fact that the imidazolium-based ILs have nanometer scale structures consisting of ionic and neutral (alkyl chain) domains. It is also found that there is a clear correlation between the ionic diffusion and viscosity, indicating that the ionic diffusion is mainly associated with the glass transition which is one of the characteristics of imidazolium-based ILs.
Journal of Chemical Physics


ionic liquid, neutron scattering, relaxation


Kofu, M. , Tyagi, M. , Inamura, Y. , Miyazaki, K. and Yamamuro, O. (2015), Quasielastic Neutron Scattering Studies on Glass-Forming Ionic Liquids with Imidazolium Cations, Journal of Chemical Physics, [online], (Accessed July 23, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created December 20, 2015, Updated October 12, 2021