An unusual slowdown of fast diffusion in a room temperature ionic liquid confined in mesoporous carbon
1 Chemical and Engineering Materials Division, Neutron Scattering Directorate, Oak Ridge National Laboratory - Oak Ridge, TN 37831, USA
2 Chemical Science Division, Oak Ridge National Laboratory - Oak Ridge, TN 37831, USA
Received: 17 January 2013
Accepted: 19 March 2013
Using quasielastic neutron scattering in the temperature range from 290 to 350 K, we show that the diffusive motions in a room temperature ionic liquid [H2NC(dma)2][BETI] become faster for a fraction of cations when the liquid is confined in a mesoporous carbon. This applies to both the localized and long-range translational diffusive motions of the highly mobile cations, although the former exhibit an unusual trend of slowing-down as the temperature is increased, until the localized diffusivity is reduced to the bulk ionic liquid value at a temperature of 350 K.
PACS: 65.20.-w – Thermal properties of liquids / 66.10.cg – Mass diffusion, including self-diffusion, mutual diffusion, tracer diffusion, etc. / 61.05.fg – Neutron scattering (including small-angle scattering)
© EPLA, 2013