On the evaporation, bonding, and adsorbate capture of an ionic liquid on Au(111)

Abstract

Temperature programmed desorption has been used to measure the bonding of 1-methyl-3ethylimidiazolium bis [(trifluoromethyl) Au(111), and the bonding of acetone within the ionic liquid (IL) at both the liquid-vacuum and liquid-Au(111) interfaces. Multilayer evaporation the ionic liquid occurred with an activation energy of 126 AE 5 kJ mol À1 and a preexponential term of 10 16AE1 s À1 , the evaporation mechanism being the direct emission into the vacuum of an ion pair from within the liquid surface. [C 2 C 1 Im][Tf 2 N] chemisorbed to Au(111) had an activation energy for desorption which varied from 158 to 132 kJ mol À1 for a coverage change of 0 / q / 1.0.The chemisorbed layer was thought to comprise a single layer of co-planar ions at q ¼ 0.5 with dipoles parallel to the surface, and a bi-layer at q ¼ 1 with dipoles perpendicular to the surface. The acetone experiments consisted of a layer of porous ionic liquid glass deposited on top of a layer of solid acetone at 100 K. During desorption acetone was captured within the ionic under-layer of the glass with an activation energy for subsequent desorption that dropped from 54 to 43 kJ mol À1 for 0 / q / 1.0. This variation in energy is thought to be due to a range of chemical environments within the ionic under-layer.

Flexible and Self‐Healing Thermoelectric Converters Based on Thermosensitive Liquids at Low Temperature Gradient

“…According to the previous studies on the adsorption behavior of ionic liquid, anions, and cations are adsorbed alternately on electrode in the first adsorption layer. [28][29][30] Moreover, the side alkyl chain of cations prefers to point towards the liquid rather than lie in contact with electrode, in order to maximize the number of imidazolium ring adsorbing parallel on the electrode surface. Herein, the desorption behavior of ionic liquid on electrode surface are mainly influenced by three factors, including cation-electrode, anionelectrode, and cation-anion interaction.…”

Ultrathin ionic liquid films on metal surfaces: adsorption, growth, stability and exchange phenomena

“…[129] a: IL films prepared by PVD, if not indicated otherwise. 126 [92] 134(2) [88] 137(5) [92] 1280 [140] TPD; broad range for WL desorption. [92] Au ( 149(2) [88] 380 [140] TP-XPS; WL desorption shifts to < 370 K after replacement by [C 8 [140] TP-XPS; WL desorption shifts to < 420 K on 2H-TPPcovered Ag (111).…”

“…126 [92] 134(2) [88] 137(5) [92] 1280 [140] TPD; broad range for WL desorption. [92] Au ( 149(2) [88] 380 [140] TP-XPS; WL desorption shifts to < 370 K after replacement by [C 8 [140] TP-XPS; WL desorption shifts to < 420 K on 2H-TPPcovered Ag (111). [81][82][83] Au ( 157 [221] 162(3) [88] 12 [140] TPD; same temperature for multilayer and WL desorption.…”

“…s -1 from literature [92]; b: See Figure 7(a); TPD: Temperature-programmed desorption; TP-XPS: Temperature-programmed XPS; TP-UPS:…”

“…During deposition, the chamber background pressure was typically around 1 × 10 −9 mbar. Most alkylimidazolium ILs evaporate intact in the form of neutral ion pairs [69,71,[79][80][81][82]86,[88][89][90][91][92][93][94][95]. The XP spectra of the thin films were compared to spectra of macroscopically thick IL films prepared ex-situ, and no indications of decomposition were observed [80][81][82][83].…”