Voltammetry of Ion Transfer across the Electrochemically Polarized Micro Liquid-Liquid Interface between Water and a Room-temperature Ionic Liquid, Tetrahexylammonium Bis(trifluoromethylsulfonyl)imide, Using a Glass Capillary Micropipette
Voltammetry of Ion Transfer across the Electrochemically Polarized Micro Liquid-Liquid Interface between Water and a Room-temperature Ionic Liquid, Tetrahexylammonium Bis(trifluoromethylsulfonyl)imide, Using a Glass Capillary Micropipette
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DOI：
10.2116/analsci.22.667
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发表时间：
2006-05
影响因子：
1.6
通讯作者：
N. Tsujioka;Seiichi Imakura;Naoya Nishi;T. Kakiuchi
中科院分区：
文献类型：
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作者：
N. Tsujioka;Seiichi Imakura;Naoya Nishi;T. Kakiuchi
本文用伏安法研究了室温离子液体（RTIL）或室温熔盐双（三氟甲基磺酰基）酰亚胺四己基铵（THAC_1C_1N）与水之间的极化界面上的离子转移。纳安级的小电流避免了粘性离子液体相中iR下降的问题。中等亲水性离子（如BF_4^-和ClO_4^-）从毛细管中的水相转移到浸没毛细管的THAC_1C_1N主体的伏安图显示出稳态特性，即电流不依赖于高达几百毫伏每秒的扫描速率，并且极限电流区域中的平台与分析物离子的体浓度成比例。由于稳态电流，这大概是归因于一个非圆柱形的几何形状的毛细管尖端，疏水性的相对大小，或亲和力的RTIL，一系列的离子，可以确定从伏安图的半波电位。
Ion transfer across the polarized interface between a room-temperature ionic liquid (RTIL) or room-temperature molten salt, tetrahexylammonium bis(trifluoromethylsulfonyl)imide (THAC_1C_1N), and water has been studied voltammetrically using a micro liquid–liquid interface formed at the orifice of a glass capillary micropipette. A small current of nanoampere level circumvents the problem of the iR drop in the viscous ionic liquid phase. Voltammograms for the transfer of moderately hydrophilic ions, such as BF_4^− and ClO_4^−, from the aqueous phase in the capillary to the bulk of THAC_1C_1N in which the capillary is submerged, show steady-state characteristics in that the current does not depend on the scan rate up to a few hundred millivolt per second, and the plateau in the limiting current region is proportional to the bulk concentration of analyte ions. Owing to the steady-state current, which is presumably ascribed to a noncylindrical geometry of the capillary tip, the relative magnitude of the hydrophobicity, or the affnity to the RTIL, of a series of ions can be determined from the half-wave potentials of voltammograms.