Understanding the wettability of nanometer-thick room temperature ionic liquids(RTILs) on solid surfaces  

作　　者：Xiao Gong Lei Li 

机构地区：[1]Department of Chemical & Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh [2]State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology

出　　处：《Chinese Chemical Letters》2017年第11期2045-2052,共8页中国化学快报（英文版）

基　　金：the American Chemical Society Petroleum Research Fund (ACS PRF No. 54840-DNI5);Advanced Storage Technology Consortium (ASTC);Taiho Kogyo Tribology Research Foundation (TTRF) for the financial support;the financial support of the National Natural Science Foundation of China (No. 21774098)

摘　　要：Many important applications of room temperature ionic liquids （RTILs）, e.g., lubrication, energy storage and catalysis, involve RTILs confined to solid surfaces. In order to optimize the performance, it is critical to understand the wettability of nanometer-thick RTILs on solid surfaces. In this review, the recent progress in this filed is presented. First, the macroscopic wettability of RTILs on solids will be discussed briefly. Afterwards, the wetting of nanometer-thick RTILs will be discussed with the emphasis on RTIL/mica and RTIL/graphite interfaces since mica and graphite not only are mostly studied but also have important real-life applications. For RTIL/mica interface, the extended layering that promotes the wetting has been extensively reported and it is generally accepted that the electrostatic interaction at the RTIL/mica interface is the key. However, recent works from others and us highlight the unexpected effect of water： Water enables ion exchange between K^＋ and the cations of RTILs on the mica surface and thus triggers the ordered packing of cations/anions in RTILs, resulting in extended layering. Different from mica, there is no electrical charge on the graphite surface. Interestingly, previous reports showed inconsistent results on the wettability of RTILs on graphite. Recent research from others and us suggested that π-π^＋ stacking between sp2 carbon and the imidazoliumcation inMany important applications of room temperature ionic liquids （RTILs）, e.g., lubrication, energy storage and catalysis, involve RTILs confined to solid surfaces. In order to optimize the performance, it is critical to understand the wettability of nanometer-thick RTILs on solid surfaces. In this review, the recent progress in this filed is presented. First, the macroscopic wettability of RTILs on solids will be discussed briefly. Afterwards, the wetting of nanometer-thick RTILs will be discussed with the emphasis on RTIL/mica and RTIL/graphite interfaces since mica and graphite not only are mostly studied but also have important real-life applications. For RTIL/mica interface, the extended layering that promotes the wetting has been extensively reported and it is generally accepted that the electrostatic interaction at the RTIL/mica interface is the key. However, recent works from others and us highlight the unexpected effect of water： Water enables ion exchange between K^＋ and the cations of RTILs on the mica surface and thus triggers the ordered packing of cations/anions in RTILs, resulting in extended layering. Different from mica, there is no electrical charge on the graphite surface. Interestingly, previous reports showed inconsistent results on the wettability of RTILs on graphite. Recent research from others and us suggested that π-π^＋ stacking between sp2 carbon and the imidazoliumcation in

关 键 词：Wettability Ionic liquids Interfaces Layering Nanometer-thick film 

分 类 号：O647[理学—物理化学]