TY - JOUR
T1 - Structures of Ionic Liquids Having Both Anionic and Cationic Octyl Tails
T2 - Lamellar Vacuum Interface vs Sponge-Like Bulk Order
AU - Amith, Weththasinghage Don
AU - Hettige, Jeevapani J.
AU - Castner, Ed
AU - Margulis, Claudio J.
PY - 2016/10/6
Y1 - 2016/10/6
N2 - Numerous experimental and computational studies have shown that the structure of ionic liquids is significantly influenced by confinement and by interactions with interfaces. The nature of the interface can affect the immediate ordering of cations and anions, changing important rheological characteristics relevant to lubrication. Most studies suggest that such changes are local or short-ranged and that bulk properties are reestablished on a length scale of a few nanometers. The current study focuses on the 1-methyl-3-octylimidazolium octylsulfate ionic liquid for which both the cation and anion have moderate length linear alkyl tails. For this system, we find that the bulk phase is dominated by the very common sponge-like morphology characteristic of many ionic liquids. However, at the vacuum interface, a lamellar structure is observed that is not restricted to the vicinity of the surface but instead extends across the full 9 nm slab of our simulation. We suspect that in reality it could extend significantly beyond this.
AB - Numerous experimental and computational studies have shown that the structure of ionic liquids is significantly influenced by confinement and by interactions with interfaces. The nature of the interface can affect the immediate ordering of cations and anions, changing important rheological characteristics relevant to lubrication. Most studies suggest that such changes are local or short-ranged and that bulk properties are reestablished on a length scale of a few nanometers. The current study focuses on the 1-methyl-3-octylimidazolium octylsulfate ionic liquid for which both the cation and anion have moderate length linear alkyl tails. For this system, we find that the bulk phase is dominated by the very common sponge-like morphology characteristic of many ionic liquids. However, at the vacuum interface, a lamellar structure is observed that is not restricted to the vicinity of the surface but instead extends across the full 9 nm slab of our simulation. We suspect that in reality it could extend significantly beyond this.
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U2 - 10.1021/acs.jpclett.6b01763
DO - 10.1021/acs.jpclett.6b01763
M3 - Article
AN - SCOPUS:84990030057
VL - 7
SP - 3785
EP - 3790
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 19
ER -