Fast Ion‐Transfer Processes at Nanoscopic Liquid/Liquid Interfaces

Li, Qing; Xie, Sishen; Liang, Zexi; Meng, Xin; Liu, Shujuan; Girault, Hubert H.; Shao, Yuanhua

doi:10.1002/anie.200903143

Cited by 94 publications

(112 citation statements)

References 29 publications

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“…A comparable value of the apparent standard rate constant of 0.2 cm s À1 has been recently reported also for the TEA + ion transfer across the water/ 1,2-DCE interface supported at the tip of a microcapillary based on the equilibrium impedance and the steady-state voltammetric measurements [19]. On the other hand, these results disagree with the kinetic data obtained by the steady-state voltammetry at the nanoscopic ITIES yielding the values of 2.4 cm s À1 [20], 5.2 cm s À1 [21] or 120 cm s À1 [22]. The possible effects leading to an overestimation of the rate constant in the nanopipette voltammetry have been summarized [23].…”

Section: Impedance Measurementscontrasting

confidence: 70%

“…The possible effects leading to an overestimation of the rate constant in the nanopipette voltammetry have been summarized [23]. Based on an analysis of the reported kinetic data, a conclusion was made [21] that the extremely high value of 120 cm s À1 [22] is likely to be overestimated due to an incorrect expression for the mass transfer coefficient used, and that the actual value should be ca. 10 times lower.…”

Section: Impedance Measurementsmentioning

confidence: 99%

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Some aspects of impedance measurements at the interface between two immiscible electrolyte solutions in the four-electrode cell

Trojánek

Mareček

Samec

2015

Electrochimica Acta

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Section: Impedance Measurementscontrasting

confidence: 70%

Section: Impedance Measurementsmentioning

confidence: 99%

Some aspects of impedance measurements at the interface between two immiscible electrolyte solutions in the four-electrode cell

Trojánek

Mareček

Samec

2015

Electrochimica Acta

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“…2,3 While the simplest nanopipettes contain just a single channel, multichannel devices are also possible, which increases the versatility of nanopipettes for nanoscience applications. 4,5 The channels can be open 5,6 (filled with electrolyte and a control electrode) or functionalized with deposited carbon, for example, to produce ultramicroelectrodes (UMEs) 7,8 that can also be further functionalized [9][10][11] to tune the sensory properties. Nanoelectrodes can also be fabricated by electrochemically plating nanopipettes with a variety of different metals.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Nanopipettes

et al. 2016

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Nanopipettes are widely used in electrochemical and analytical techniques as tools for sizing, sequencing, sensing, delivery and imaging. For all of these applications, the response of a nanopipette is strongly affected by its geometry and surface chemistry. As the size of nanopipettes becomes smaller, precise geometric characterization is increasingly important, especially if nanopipette probes are to be used for quantitative studies and analysis. This contribution highlights the combination of data from voltage-scanning ion conductivity experiments, transmission electron microscopy (TEM) and finite element method (FEM) simulations to fully characterize nanopipette geometry and surface charge characteristics, with an accuracy not achievable using existing approaches. Indeed, it is shown that presently used methods for nanopipette characterization can lead to highly erroneous information on nanopipettes. The new approach to characterization further facilitates high-level quantification of the behavior of nanopipettes in electrochemical systems, as demonstrated herein for a scanning ion conductance microscope (SICM) setup.

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“…[11,12] Doe et al measured ITVs of tetraethylammonium ions at the interface between the frozen aqueous phase and 1,2-dichloroethane (DCE).…”

mentioning

confidence: 99%

Ion‐Transfer Voltammetry at the Interface between Organic and Salt‐Doped Ice Phases

Harada

Okada

2015

ChemElectroChem

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Ions play critical roles in reactions of biological, environmental, and industrial importance under frozen conditions. Transfer voltammetry of tetramethylammonium (TMA) and K + ions is measured at the interface between frozen aqueous NaCl and dichloroethane to give an insight into chemistry in frozen aqueous phases. The ion-transfer current of TMA initially increasesa st he temperature becomes lower from the freezing point, but the further decrease in temperature reduces the transfer current. The half-wave potentialo ft he TMA transfer shows anegative shiftwhen the liquid phase volumeiss maller than 10 %o ft he total volume of the frozen phase. Similarly, the half-wave potential of the facilitated transfer of K + by crown ether complexation also becomes negative with decreasingt emperature, due to the freeze concentration of K + in the liquid phase.Freezingi sa ni mportant process widely utilized in agriculture, fishery,t he food industry,m edicine, biological technologies, and so forth. [1,2] Although chemical reactions are usually retarded at lower temperatures,s ome examples have been reported for freeze enhancements of reactionk inetics.[3] Frozen aqueous solutions are therefore systems of scientific and practical interest. Salts are often involved in aqueous frozen mediaa nd play important roles in chemical processes occurring therein. In frozen aqueous solutions, salt crystals and ice are separately formed at the temperature lower than the eutectic point of the system (T eu ). When the temperature of this solid mixture increasesp ast T eu ,t he salt is dissolved in the liquid phase (LP) that coexists with ice below the melting point. [4] One possible reason for the accelerationso fr eactions in the frozen systems is the freeze concentrationo fs olutes. This aspect has been wells tudied from ak inetic viewpoint;t he reactions of order two or highera re accelerated by freeze concentration.[5] Another explanation of the kinetic acceleration is ap Hc hange in the LP upon freezing. As stated above, ions are mostly expelled from the ice phase as salts but are partly entrapped by ice. If an anion is better distributedt ot he ice phase than ac ation,t he negative charge shortage occursi n the LP,w hich is relaxed by the transfer of OH À to the LP.[6] The LP becomes more basic and the ice is acidified as ar esult. The pH shift by freezing explains the acceleration of some reactions quite well. [7] However,an umber of reactions occurring in the LP cannot be explained by theseorigins. [3,4,8] Unusual reactions in the LP possibly come from the properties of water therein,w hicha re different from those in unfrozen aqueous solution. Ar ecent molecular dynamics study has indicated that protont ransfer,a cids olvation, and ionization in aq uasi-liquid layer,w hich is formed on the surface of ice below the melting point, are different from that of bulk water.[9] The structure of liquid water in contact with ice is affected by ice, and as ar esult its properties are also influenced. However, no experimentali nformation is a...

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Fast Ion‐Transfer Processes at Nanoscopic Liquid/Liquid Interfaces

Cited by 94 publications

References 29 publications

Some aspects of impedance measurements at the interface between two immiscible electrolyte solutions in the four-electrode cell

Some aspects of impedance measurements at the interface between two immiscible electrolyte solutions in the four-electrode cell

Characterization of Nanopipettes

Ion‐Transfer Voltammetry at the Interface between Organic and Salt‐Doped Ice Phases

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