Interface solvent structure

W. R. Fawcett. Molecular models for the solvent structure at polarizable interfaces. Israeli J Chem 75 3-16, 1979. 

In concentrated NaOH solutions, however, the deviations of the experimental data from the Parsons-Zobel plot are quite noticeable.72 These deviations can be used290 to find the derivative of the chemical potential of a single ion with respect to both the concentration of the given ion and the concentration of the ion of opposite sign. However, in concentrated electrolyte solutions, the deviations of the Parsons-Zobel plot can be caused by other effects,126 279"284 e.g., interferences between the solvent structure and the Debye length. Thus various effects may compensate each other for distances of molecular dimensions, and the Parsons-Zobel plot can appear more straight than it could be for an ideally flat interface. 

Guidelli and co-workers336-338 measured the potential of zero charge by chronocoulometry. They found that the pzc was independent of the electrolyte concentration in both NaC104 and Na2S04. However, Ea=0 in the presence of sulfates was ca. 40 mV more negative. These authors have explained this apparent discrepancy in terms of the perturbation of the solvent structure at the interface by the ions at the electrode surface, which are, however, nonspecifically adsorbed. 

Fields, B.A., F.A. Goldbaum, W. Dall Acqua, E.L. Malchiodi, A. Cauerhff, F.P. Schwarz, X. Ysem, R.J. Poljak, and R.A. Mariuzza. 1996. Hydrogen bonding and solvent structure in an antigen-antibody interface. Crystal structures and thermodynamic characterization of three Fv mutants complexed with lysozyme. Biochemistry 35 15494-15503. 

The basic theories of physics - classical mechanics and electromagnetism, relativity theory, quantum mechanics, statistical mechanics, quantum electrodynamics - support the theoretical apparatus which is used in molecular sciences. Quantum mechanics plays a particular role in theoretical chemistry, providing the basis for the valence theories which allow to interpret the structure of molecules and for the spectroscopic models employed in the determination of structural information from spectral patterns. Indeed, Quantum Chemistry often appears synonymous with Theoretical Chemistry it will, therefore, constitute a major part of this book series. However, the scope of the series will also include other areas of theoretical chemistry, such as mathematical chemistry (which involves the use of algebra and topology in the analysis of molecular structures and reactions) molecular mechanics, molecular dynamics and chemical thermodynamics, which play an important role in rationalizing the geometric and electronic structures of molecular assemblies and polymers, clusters and crystals surface, interface, solvent and solid-state effects excited-state dynamics, reactive collisions, and chemical reactions. 

The situation inside an electrolyte—the ionic aspect of electrochemistry—has been considered in the first volume of this text. The basic phenomena involve— ion—solvent interactions (Chapter 2), ion—ion interactions (Chapter 3), and the random walk of ions, which becomes a drift in a preferred direction under the influence of a concentration or a potential gradient (Chapter 4). In what way is the situation at the electrode/electrolyte interface any different from that in the bulk of the electrolyte To answer this question, one must treat quiescent (equilibrium) and active (nonequilibrium) interfaces, the structural and electrical characteristics of the interface, the rates and mechanism of changeover from ionic to electronic conduction, etc. In short, one is led into electrodics, the newest and most exciting part of electrochemistry. 

What is next The above results give only a particular view of one part of the interface, i.e., the solvent structure. It would be good to End how this solvent and its changes in configuration affect—if at all—the total interfacial properties, for example, properties that we are already familiar with, such as the surface potential or the capacity. Thus, what would be the expression for the surface potential due to a layer... 

S. Trasatti. The Electrode Potential, in Comprehensive Treatise of Electrochemistry, Vol. 1, J. O M. Bockris, B.E. Conway and E. Veager. Eds. Plenum (1980), chapter 2 B.E. Conway, The State of Water and Hydrated Ions at Interfaces, Adv. Colloid Interface Sci. 8 (1977) 91 W.R. Fawcett, Molecular Models for Solvent Structure at Polarizable Interfaces. Isr. J. Chem. 18 (1979) 3 M.A. Habib, Solvent Dipoles at the Electrode-Solution Interface. in Modem Aspects of Electrochemistry, Vol. 12, J. O M. Bockris and B.E. Conway. Eds. Plenum (1977) 131 S. Trasatti, Solvent Adsorption and Double Layer Potential Drop at Electrodes, in Modem Aspects of Electrochemistry, B.E. Conway and J. O M. Bockris, Eds. Vol. 13 Plenum (1979) chapter 2 J. O M. Bockris. K-T. Jeng, Water Structure at Interfaces The Present Situation. Adv. Colloid Interface Set 33 (1990) 1. 

Structure of Electrified Interfaces, J. Llpowski, P.N. Ross, Eds. V.C.H. Publishers (1993). (Double layer structure, including solvent structure emphasis on metal electrodes.)... 

The SASA approach makes no attempt to separate the free energy of solvation into distinct components, such as the ENP and CDS terms, but simply assumes the net solvation energy to be proportional to the SASA. In later sections we will consider models that separate these effects. Even there, though, by grouping cavity and solvent structural effects into the same term, one will not distinguish solvent structural effects that occur upon creating a cavity from those over and above the change at a solvent—vacuum interface. 

The calculations performed to date suggest that (i) the details of the short-range wall-water potentials dominate the average orientation of the contact layer of water (in combination with the strong water-water and charged wall-water interactions) and (ii) beyond the first layer the structure is insensitive to these details. The layered solvent structure extends approximately 15 A into the bulk of the liquid, representing about 4 layers of water molecules, a distance remarkably similar to that found in earlier simulations of an ice / water interface. The potential of zero charge is calculated to be -32 mV. The differential capacitance can be calculated, as discussed by Booth et al7... 

Previously reported implicit solvent approaches [33] take into account the solvent structuring induced by the solvent-hydrophobe interface (Fig. 3.7), translate this... 

Some Effects of Hydrocarbon Solvent Structure on the Phase Behavior of Distearoyl Lecithin Monolayers at the Hydrocarbon/Water Interface... 

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