Effect of water on the interfacial structures of room‐temperature ionic liquids. (2nd September 2018)

• Record Type: Journal Article
• Authors: Kawada, Shouhei; Kodama, Eri; Sato, Keisuke; Ogawa, Shuhei; Watanabe, Masaya; Okubo, Hikaru; Sasaki, Shinya
• Is Part Of: Surface and interface analysis. Volume 51:Number 1(2019)
• Page Start: 17
• Page End: 20
• Publication Date: 2018-09-02
• Subjects: room‐temperature ionic liquids -- water -- atomic force microscopy -- Fourier transform infrared spectroscopy; Surfaces (Physics) -- Periodicals; Surface chemistry -- Periodicals; Thin films -- Periodicals; 541.33
• DOI: 10.1002/sia.6536
• Languages: English
• ISSNs: 0142-2421

Abstract

Abstract : 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% H2 O solution. FT‐IR results indicated that the layer structure of [EMIM][DCN] was disturbed by the addition of H2 O. Therefore, the solution containing water exhibited a high friction force.