Physical vapor deposition of [EMIM][Tf2N]: a new approach to the modification of surface properties with ultrathin ionic liquid films.
Ultrathin films of the ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [EMIM][Tf(2)N], are prepared on a glass substrate by means of an in situ thermal-evaporation/condensation process under ultrahigh-vacuum conditions. By using X-ray photoelectron spectroscopy (XPS), it is demonstrated that the first layer of the IL film grows two dimensionally, followed by the three-dimensional growth of successive layers. The first molecular layer consists of a bilayer, with the [EMIM](+) cations in contact to the surface and the [Tf(2)N](-) anions at the vacuum side. The ultrathin IL films are found to be stable under ambient conditions.
Cremer
Till
T
Lehrstuhl für Physikalische Chemie, Universität Erlangen-Nürnberg, Erlangen, Germany.
Killian
Manuela
M
Gottfried
J Michael
JM
Paape
Natalia
N
Wasserscheid
Peter
P
Maier
Florian
F
Steinrück
Hans-Peter
HP
D002627:Chemistry, Physical; D005898:Glass / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry*; D007094:Imides / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D008567:Membranes, Artificial; D015394:Molecular Structure; D013053:Spectrophotometry; D013499:Surface Properties; D013997:Time Factors; D014835:Volatilization; D014965:X-Rays
C506652:1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide; D007093:Imidazoles; D007094:Imides; D052578:Ionic Liquids; D008567:Membranes, Artificial