Intrinsic Structure of the Interface of Partially Miscible Fluids: An Application to Ionic Liquids
- Author(s)
- Gyoergy Hantal, Marcello Sega, Sofia Kantorovich, Christian Schroeder, Miguel Jorge
- Abstract
We investigate by means of Molecular Dynamics simulations how the intrinsic surface structure of liquid/liquid interfaces involving ionic liquids depends on the opposite phase of varying polarity. We study 1-n-butyl-3-methylimidazolium hexafluorophosphate (BMIM PF
6) and 1-n-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imid (BMIM NTf
2). The opposite phase is either cyclohexane or water, but as a reference, IL-vacuum interfaces are also studied. We combine a distance-based cluster search algorithm with the ITIM intrinsic analyzing method to separate liquid phases showing non-negligible mutual miscibility and to identify atoms residing at the instantaneous surface. In contrast to the well structured surface of IL-vacuum systems, at liquid/liquid interfaces of ILs density correlations, ionic associations, and orientational preferences are all weakened, this effect being much more pronounced when the other species is water. In such systems we observe a drastic reduction in the presence of the cation at the surface and an increase of appearance of polar moieties (of both the cations and anions) leading to decreased apolar character of the interface. Furthermore, cations are mostly found to turn with their butyl chains toward the bulk while having their methyl groups sticking toward water. Anion-cation associations are reduced and partially replaced by water-anion and rarely also water-cation associations.
- Organisation(s)
- Department of Computational Biological Chemistry, Computational and Soft Matter Physics
- External organisation(s)
- Eszterházy Károly University of Applied Sciences, Ural Federal University, University of Strathclyde
- Journal
- The Journal of Physical Chemistry Part C (Nanomaterials and Interfaces)
- Volume
- 119
- Pages
- 28448-28461
- No. of pages
- 14
- ISSN
- 1932-7447
- DOI
- https://doi.org/10.1021/acs.jpcc.5b09810
- Publication date
- 12-2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 104017 Physical chemistry, 103006 Chemical physics
- Keywords
- ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials, Energy(all), Surfaces, Coatings and Films, Physical and Theoretical Chemistry
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/intrinsic-structure-of-the-interface-of-partially-miscible-fluids-an-application-to-ionic-liquids(d7cd2aa4-65dd-4bc4-bed4-82f3d4b74d2c).html