I&EC 35 |
| Nanometer-scale structuring in room-temperature ionic liquids is observed using molecular simulation. The ionic liquids studied belong to the 1-alkyl-3-methylimidazolium family with hexafluorophosphate or with bis(trifluoromethanesulfonyl)amide as the anions. They were represented by an all-atom force field of the OPLS_AA family developed specifically for these compounds. For ionic liquids with alkyl side chains in the cation longer than or equal to butyl, segregation is observed between, on one side, the strongly charged parts of the cations and the anions, and on the other, the non-polar side chains of the cations. The alkyl chains aggregate in non-polar domains that permeate a tridimensional network of ionic channels formed by the charged parts of the ions. The nanostructures are visualised by color-coding the atoms belonging to the two types of domain, and once tagged the pure ionic liquid becomes analogous to systems exhibiting microphase separation. As the length of the alkyl chain increases, the non-polar domains become larger, more connected and cause swelling of the ionic network. The consequences of these nanostructural features on the properties of the ionic liquids are interpreted.
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Ionic Liquids: Not Just Solvents Anymore OR Ionic Liquids: Parallel Futures (Sponsored by Green Chemistry and Engineering, Separation Science and Technology and Novel Chemistry with Industrial Applications Sub-Divisions)
1:30 PM-5:45 PM, Sunday, 26 March 2006 Georgia World Congress Center -- B314, Oral
Division of Industrial and Engineering Chemistry |
