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Effect of water on the interfacial structures of room‐temperature ionic liquids
Author(s) -
Kawada Shouhei,
Kodama Eri,
Sato Keisuke,
Ogawa Shuhei,
Watanabe Masaya,
Okubo Hikaru,
Sasaki Shinya
Publication year - 2019
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.6536
Subject(s) - dicyanamide , ionic liquid , fourier transform infrared spectroscopy , tribology , chemistry , atomic force microscopy , layer (electronics) , chemical engineering , ionic bonding , infrared spectroscopy , molecular dynamics , materials science , ion , analytical chemistry (journal) , composite material , nanotechnology , computational chemistry , organic chemistry , catalysis , engineering
The interfacial structures of cyano‐based room‐temperature ionic liquids play a very important role in reducing friction. However, the presence of water impairs their tribological performance. The interfacial structures and friction forces of 1‐ethyl‐3‐methylimidazolium dicyanamide, [EMIM][DCN], and the effect of water on these structures and forces were investigated using atomic force microscopy. In addition, the interaction of water and [EMIM][DCN] was evaluated using Fourier‐transform infrared (FT‐IR) spectroscopy. Multiple repulsive layers were observed in the [EMIM][DCN] solution. This solution showed low friction force because these repulsive layers worked as protective layers against friction. On the other hand, the specific repulsive layer characteristics of [EMIM][DCN] could not be observed in a [EMIM][DCN] + 2 wt% H 2 O solution. FT‐IR results indicated that the layer structure of [EMIM][DCN] was disturbed by the addition of H 2 O. Therefore, the solution containing water exhibited a high friction force.