Liquid electrified

Baldelli, S. (2008) Surface structure at the ionic liquid-electrified metal interface. Acc. Chem. Res., 41 (3), 421-431. Sieffert, N. and Wipff, G. (2008) Ordering of imidazolium-based ionic liquids at the r-Quartz(OOl) surface a molecular dynamics study. J. Phys. Chem. C, 112, 19560-19603. 

Atkins, R, and J. de Paula. 2009. Physical Chemistry. 9th ed. New York W. H. Freeman. Baldelli, S. 2008. Surface structure at the ionic liquid-electrified metal interface. Accounts of Chemical Research Al, no. 3 421-431. doi 10.1021/ar700185h. 

Baldelli S (2008) Surface structtue at the ionic liquid-electrified metal interface. Acc Chem Res 41 421 31... 

Wang, Z., Mu, X., Guo, M., Huang, Y., Mason, A. J., Zeng, X., (2013) Methane Recognition and Quantification by Differential Capacitance at the Hydrophobic Ionic Liquid-Electrified Metal Electrode Interface, Journal of The Electrochemical Society, 160 (6) B83-B89. 

Wang Z, Mu X, Guo M, Huang Y, Mason AJ, Zeng X (2013) Methane recognition and quantification by differential capacitance at the hydrophobic ionic liquid-electrified metal electrode interface. J Electrochem Soc 160(6) B83—B89. doi 10.1149/2.138306jes... 

In recent years, advances in experimental capabilities have fueled a great deal of activity in the study of the electrified solid-liquid interface. This has been the subject of a recent workshop and review article [145] discussing structural characterization, interfacial dynamics and electrode materials. The field of surface chemistry has also received significant attention due to many surface-sensitive means to interrogate the molecular processes occurring at the electrode surface. Reviews by Hubbard [146, 147] and others [148] detail the progress. In this and the following section, we present only a brief summary of selected aspects of this field. 

One of the most important advances in electrochemistry in the last decade was tlie application of STM and AFM to structural problems at the electrified solid/liquid interface [108. 109]. Sonnenfield and Hansma [110] were the first to use STM to study a surface innnersed in a liquid, thus extending STM beyond the gas/solid interfaces without a significant loss in resolution. In situ local-probe investigations at solid/liquid interfaces can be perfomied under electrochemical conditions if both phases are electronic and ionic conducting and this... 

The singlet multidensity Ornstein-Zernike approach for the density profile described in this section has also been applied to study the role of association effects in the ionic liquid at an electrified interface [22]. 

As crude oil reserves dwindle, the marketplace will either transition to the electrifying of the transportation system (electric and fuel-cell vehicles and electric railways), with the electricity being produced by coal, natural gas, nuclear and renewables, or see the development of an industry to produce liquid fuel substitutes from coal, oil shale, and tar sands. It might also turn out to be a combination of both. The transition will vary by nation and will be dictated strongly by the fuels available, the economic and technological efficiencies of competitive systems, the relative environmental impacts of each technology, and the role government takes in the marketplace. 

The system of distinctions and terminology of the thermodynamic and electric potentials introduced by Lange is still very useful and recommended for describing all electrified phases and interphases. Therefore these potentials can be assigned to metal/solution (M/s), as well as the liquid/liquid boundaries created at the interfaces of two immiscible electrolyte solutions water (w) and an organic solvent (s). 

The latter report demonstrated the unique ability of this technique to resolve surface structure as well as surface composition at the electrified solid-liquid interfaces. In particular, STM has become an important tool for ex situ and in situ characterization of surfaces at the atomic level, in spite its significant limitations regarding surface composition characterization for bimetallic systems, such as the lack of contrast for different elements and the scanned surface area being too small to be representative for the entire surface. To avoid these limitations, STM has been mostly used as a complementary tool in surface characterization. 

Overall, this chapter aimed to emphasize and demonstrate the great potential of utilizing a multidisciplinary approach to bimetallic systems that combines computational methods with a number of highly sophisticated in situ and ex situ surface-sensitive techniques at electrified solid-liquid interfaces. Advances in the understanding of fundamental properties that govern catalytic processes at well-defined multimetallic... 

Every liquid interface is usually electrified by ion separation, dipole orientation, or both (Section II). It is convenient to distinguish two groups of immiscible liquid-liquid interfaces water-polar solvent, such as nitrobenzene and 1,2-dichloroethane, and water-nonpolar solvent, e.g., octane or decane interfaces. For the second group it is impossible to investigate the interphase electrochemical equilibria and the Galvani potentials, whereas it is normal practice for the first group (Section III). On the other hand, these systems are very important as parts of the voltaic cells. They make it possible to measure the surface potential differences and the adsorption potentials (Section IV). 

II. ELECTRIFIED LIQUID-LIQUID INTERFACES AND THEIR ELECTRICAL PQTENTIALS... 

The availability of thermodynamically reliable quantities at liquid interfaces is advantageous as a reference in examining data obtained by other surface specific techniques. The model-independent solid information about thermodynamics of adsorption can be used as a norm in microscopic interpretation and understanding of currently available surface specific experimental techniques and theoretical approaches such as molecular dynamics simulations. This chapter will focus on the adsorption at the polarized liquid-liquid interfaces, which enable us to externally control the phase-boundary potential, providing an additional degree of freedom in studying the adsorption of electrified interfaces. A main emphasis will be on some aspects that have not been fully dealt with in previous reviews and monographs [8-21]. 

The author acknowledges the generous support of the Fond national Suisse and fruitful discussions at the Faboratoire d Electrochimie of the Ecole Polytechnique Federale de Lausanne with J. Rinuy, A. Piron, P. Galletto, D. J. Fermin, and H. FI. Girault. The Faboratoire d Electrochimie is part of the European Network on Training and Mobility of Researchers Organization, Dynamics and Reactivity of Electrified Liquid-Liquid Interfaces (ODRELLI). ... 

Capacitance and surface tension measurements have provided a wealth of data about the adsorption of ions and molecules at electrified liquid-liquid interfaces. In order to reach an understanding on the molecular level, suitable microscopic models have had to be considered. Interpretation of the capacitance measurements has been often complicated by various instrumental artifacts. Nevertheless, the results of both experimental approaches represent the reference basis for the application of other techniques of surface analysis. 

We want to express our gratitude to Prof. Hubert H. Girault of the Laboratoire d Electrochmie of the Ecole Polytechnique Federale de Lausanne as well as to Prof. Bernard Testa and Dr. Pierre-Alain Carrupt of the Institut de Chimie Therapeutique of the Universite de Lausanne (Switzerland) for their fruitful collaboration, insightful discussions, and valuable comments on this manuscript. We are also indebted to the Swiss National Science Foundation for its support. Laboratoire d Electrochimie is part of the European Training and Mobility Network on Organization Dynamics and Reactions at Electrified-Liquid Interfaces (ODRELLI). 

In the following we will focus on three molecular electronics test beds as developed and employed for applications at electrified solid/liquid interfaces (1) STM and STS, (2) assemblies based on horizontal nanogap electrodes, and (3) mechanically-controlled break junction experiments. For a more detailed description of the methods we refer to several excellent reviews published recently [16-22]. We will also address specific aspects of electrolyte gating and of data analysis. 

Tao et al. [32] pioneered a technique based on the formation of single molecular junctions between the tip of an STM and a metal substrate. The method was adapted by other groups, modified and applied to a large number of molecular conductance studies at (electrified) solid/liquid interfaces [33, 113-119]. For details we refer to Sect. 2.3. 

Zeleny, J. Instability of Electrified Liquid Surfaces. Phys. Rev. 1917,10, 1-7. 

The ILs interact with surfaces and electrodes [23-25], and many more studies have been done that what we can cite. As one example, in situ Fourier-transform infrared reflection absorption spectroscopy (FT-IRAS) has been utilized to study the molecular structure of the electrified interphase between a l-ethyl-3-methylimidazolium tetrafluoroborate [C2Qlm][BF4] liquid and gold substrates [26]. Similar results have been obtained by surface-enhanced Raman scattering (SERS) for [C4Cilm][PFg] adsorbed on silver [24,27] and quartz [28]. 

A rather unusual example of the ubiquitous role of electrified interfaces is based on the friction between two solids which, in the presence of liquid films, may depend on the double layers at their interfaces. Thus, the efficiency of a wetted rock drill depends on the double-layer structure at the metal/drill/aqueous solution interface. 

Loscertales, I.G., Barrero, A., Guerrero, I., Cortijo, R., Marquez, M., Ganan-Calvo, A.M. (2002). Micro/nano encapsulation via electrified coaxial liquid jets. Science, 295, 1695-1698. 

Langevin and Biquard [33] showed that the evaportion of a liquid (alcohol, ether, benzene) does not electrify the residual solvent. Hence evaporation of the solvent in driers cannot lead to electrification of the powder. In the opinion of these authors nitrocellulose powder may be ignited by the discharge of the condenser at a voltage of 3000 V, if the condenser charge is greater than 0.3 fiF. 

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