Dynamic and structural properties of room-temperature ionic liquids near silica and carbon surfaces

Journal Article · Thu Jul 11 00:00:00 EDT 2013 · Langmuir

DOI:https://doi.org/10.1021/la401172z· OSTI ID:1105941

Li, Song ^[1]; Han, Kee Sung ^[2]; Feng, Guang ^[1]; Hagaman, Edward W. ^[2]; Vlcek, Lukas ^[2]; Cummings, Peter ^[3]

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1. Vanderbilt Univ., Nashville, TN (United States). Dept. of Chemical and Biomolecular Engineering
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division
3. Vanderbilt Univ., Nashville, TN (United States). Dept. of Chemical and Biomolecular Engineering; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)

The dynamic and structural properties of a room-temperature ionic liquid (RTIL) 1-butyl-3-methyl-imidazolium(trifluoromethanesulfonimide) ([C₄mim][Tf₂N]) confined in silica and carbon mesopores were investigated by molecular dynamics (MD) simulations and nuclear magnetic resonance (NMR) experiments. The complex interfacial microstructures of confined [C₄mim][Tf₂N] are attributed to the distinctive surface features of the silica mesopore. The temperature-dependent diffusion coefficients of [C₄mim][Tf₂N] confined in the silica or carbon mesopore exhibit divergent behavior. The loading fraction (f = 1.0, 0.5, and 0.25) has a large effect on the magnitude of the diffusion coefficient in the silica pore and displays weaker temperature dependence as the loading fraction decreases. The diffusion coefficients of mesoporous carbon-confined [C₄mim][Tf₂N] are relatively insensitive to the loading faction and exhibit a temperature dependence that is similar to the bulk dependence at all loading levels. Finally, such phenomena can be attributed to the unique surface heterogeneity, dissimilar interfacial microstructures, and interaction potential profile of RTILs near silica and carbon walls.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC05-00OR22725; AC02-05CH11231
• OSTI ID: 1105941
• Journal Information: Langmuir, Vol. 29, Issue 31; ISSN 0743-7463
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY