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The presence of freely moving charges gives peculiar properties to electrolyte solutions, such as electric conductance, charge transfer, and junction potentials in electrochemical systems. These charges play a dominant role in transport processes, by contrast with classical equilibrium thermodynamics which considers the electrically neutral electrolyte compounds. The present status of transport theory does not permit a first prin­ ciples analys1s of all transport phenomena with a detailed model of the relevant interactions. Host of the models are still unsufficient for real systems of reasonable complexity. The Liouville equation may be adapted with some Brownian approximations to problems of interact­ ing solute particles in a continuum (solvent>; however, keeping the Liouville level beyond the limiting laws is an unsolvable task. Some progress was made at the Pokker-Planck level; however, despite a promising start, this theory in its actual form is still unsatis­ factory for complex systems involving many ions and chemical reac­ tions. A better approach is provided by the so-called Smoluchowski level in which average velocities are used, but there the hydrodyna­ mic interactions produce some difficulties. The chemist or chemical engineer, or anyone working with complex electrolyte solutions in applied research wants a general representa­ tion of the transport phenomena which does not reduce the natural complexity of the multicomponent systems. Reduction of the natural complexity generally is connected with substantial changes of the systems.

Inhaltsverzeichnis

Frontmatter

Chapter I. Basic Concepts

Abstract
Every electrolyte solution which is not in equilibrium is subjected to generalized forces which control the irreversible processes taking place in those systems. Processes of this type are transport processes and chemical reactions, including relaxation processes. Transport processes presuppose spatial inhomogeneities produced by the gradients of
  • concentration
  • electric potential
  • temperature, or
  • drift velocity.
In contrast, chemical reactions do not presuppose spatial inhomogeneities. Transport phenomena in electrolyte solutions simultaneously involve both types of irreversible processes, when the formation of ion pairs and other ion aggregates is superimposed on ion transport.
Pierre Turq, Josef M. G. Barthel, Marius Chemla

Chapter II. Coupled Processes in Electrolyte Solutions

Abstract
There are various ways to treat irreversible thermodynamic processes in which electrolyte solutions exhibit coupled transport processes and chemical reactions. The phenomenological procedure chosen here is that of irreversible thermodynamics relating the flows to the underlying gradients. Strongly coupled relaxation processes evading the description by a set of one-particle equations will not be considered, such as the relaxation effect of electric migration and self-diffusion. The following treatment is based on sets of two-particle equations justified from first principles of statistical mechanics.
Pierre Turq, Josef M. G. Barthel, Marius Chemla

Chapter III. Hydrodynamic Properties

Abstract
The understanding of the transport properties of electrolyte solutions requires some basic knowledge on hydrodynamics. Without going into details chapter III gives a concise presentation of the necessary tools of this topic permitting to proceed to the applications of chapters IV to VII. The first part of this chapter is devoted to the basic principles of hydrodynamics, permitting in the second part the quantitative description of hydrodynamic interactions between moving particles in a fluid. Limitation is made to the level of the Navier-Stokes theory commonly used in the theory of electrolyte solutions.
Pierre Turq, Josef M. G. Barthel, Marius Chemla

Chapter IV. Excess Quantities

Abstract
Since the work of Debye and Hückel [1] every relevant theoretical treatment of electrolyte solution properties is based on the two-particle distribution function fij (\( {{\vec{r}}_{1}} \), \( {{\vec{r}}_{2}} \)) of the ions. The pair-distribution functions show the probability of finding the ions Yi and Yj (equal or different ions) at positions \( {{\vec{r}}_{1}} \) and \( {{\vec{r}}_{2}} \) in the electrolyte solution, regardless of the position of all other ions and regardless of all particle velocities.
Pierre Turq, Josef M. G. Barthel, Marius Chemla

Chapter V. The Role of Ion Aggregation and Micelle Formation Kinetics in Diffusional Transport of Binary Solutions

Abstract
This chapter is concerned with binary electrolyte solutions in which diffusion processes and rates of chemical reactions are coupled. The solutes may exist as free ions and ion pairs or higher aggregates with and without inclusion of solvent molecules. The crucial point of the discussion is the influence of the rate constants of chemical reactions on the observable diffusion coefficients, in contrast to the common point of view which treats the influence of diffusion processes on kinetics, e.g., in the kinetics of diffusion limited reactions.
Pierre Turq, Josef M. G. Barthel, Marius Chemla

Chapter VI. Diffusion, Migration and Chemical Reactions in Electrolyte Solutions beyond Ideality

Abstract
Two extensions are given in this chapter with regard to the preceding discussion: ionic migration in electrostatic fields is superimposed to diffusion and ion-aggregate formation, and a method is introduced permitting the gradual change from the state of highly dilute to more concentrated solutions.
Pierre Turq, Josef M. G. Barthel, Marius Chemla

Chapter VII. Relaxation Processes in High Frequency Electromagnetic Fields

Abstract
The preceding chapters on coupled transport and kinetic processes in electrolyte solutions reveal the complexity of charge transport, but leave the reader with unknown quantities such as the rate constants of ion-aggregate formation and decomposition. These very fast reactions can be measured in the appropriate time scale which is the nano- to picosecond range, available by microwave methods in the time and frequency domain.
Pierre Turq, Josef M. G. Barthel, Marius Chemla

Backmatter

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