Alexander Naumovich Frumkin*

Russian Journal of Electrochemistry -     

32th Frumkin Readings

Russian Journal of Electrochemistry -     

Frumkin Correction: Microscopic View

Approaches to perfecting analysis of psi-prime effects, based on modeling the reaction layer of electrochemical reactions and allowing for real molecular structure of reactants and products, are considered. Conditions of applicability of the traditional slow-discharge theory relations to systems with reactants of complicated structure are analyzed in a wide overvoltage interval. Special attention is paid to the problem of accounting for nonuniformity of charge distributions in particles of reactants and products. It is shown that it becomes essential to account for the dielectricity of the effective cavity used for modeling the particles, provided the particles are sufficiently large.     

On the Frumkin Memorial Medal

Russian Journal of Electrochemistry -     

The Frumkin Award for Young Scientists

Russian Journal of Electrochemistry -     

The 2004 Frumkin Award Competition for Young Scientists

Russian Journal of Electrochemistry -     

The 2005 Frumkin Award competition for young scientists

Information

The 2005 Frumkin Award competition for young scientists     

The 2004 Frumkin Award Competition for Young Scientists

Russian Journal of Electrochemistry -     

The 2003 Frumkin Award Competition for Young Scientists

Russian Journal of Electrochemistry -     

The 2004 Frumkin Award Competition for Young Scientists

Russian Journal of Electrochemistry -     

Adsorption parameters in the Alekseev-Popov-Kolotyrkin model complemented by the Frumkin isotherm

The method of a nonlinear regressive analysis of nonequilibrium differential capacitance curves in terms of the Alekseev-Popov-Kolotyrkin (APK) model complemented by the Frumkin isotherm is used to determine adsorption parameters of an organic cation of tetrabutylammonium, an inorganic nitrate anion, and a butanol molecule at an interface with a mercury electrode. The adsorption behavior of the nitrate anion is quantitatively described by the APK model, whereas the Frumkin model is preferable in the case of butanol. With the [C₄H₉]₄N⁺ cation adsorbed on a mercury electrode, the EDL structure is probably strongly affected by the formation of ionic pairs. Dedicated to the ninetieth anniversary of Ya.M. Kolotyrkin’s birth.     

The Frumkin Memorial Medal, 2000 Professor Roger Parsons F.R.S.C., F.R.S.*

Russian Journal of Electrochemistry -     

Surfaces and Interfaces in Electrochemistry: 2003 Frumkin Memorial Medal Award Lecture

This Award Lecture, delivered on the occasion of the presentation of the 2003 Frumkin Memorial Medal to the Author, consists of three parts: A brief introduction, a memorial section where the events in which Professor Frumkin and the author were jointly involved, and a scientific section where the main concepts at the basis of the scientific contacts between Frumkin and the author are illustrated. Among the latter, emphasis is placed on the relationship between the potential of zero charge and the electron work function of metals.     

Adsorption at liquid interfaces: The generalized Frumkin isotherm and interfacial structure

The thermodynamics of adsorption of amphiphilic surface-active compounds at the interface between two immiscible liquids is considered. At the interface, these molecules are supposed to replace a few of the adsorbed molecules of both solvents. Classical isotherms of adsorption (Frumkin, Frumkin-Damaskin, Langmuir, Henry) were based on the model of non-penetrable interface, where an adsorbate can substitute only molecules of one solvent. At the interface between two immiscible electrolytes, nonpolar oil/water interfaces, and liquid membranes amphiphilic molecules can substitute molecules of both solvent and classic isotherms cannot be used. The generalization of Frumkin isotherm for permeable and non-permeable interfaces, known as the Markin-Volkov isotherm, gives the possibility to analyze adsorption in a general case. The adsorption isotherms of pentafluorobenzoic acid at the octane/water interface at different pHs were measured by the drop-weight method. The thermodynamic parameters of pentafluorobenzoic acid (PFBA) adsorption at octane/water interface were determined. From the measurements of PFBA adsorption, the structure of the octane/water interface was determined. Substitution of one adsorbed octane molecule requires approximately three adsorbed PFBA molecules. This result shows that the orientation of solvent molecules at the interface is different from the bulk. Adsorbed octane molecules have a lateral orientation with respect to the interface. Gibbs free energy of adsorption equilibrium and thermodynamic parameters of PFBA adsorption show that the adsorption of PFBA at the octane/water interface is accompanied by a reduction in the attraction between adsorbed PFBA molecules as the pH decreases to the acidic region. Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 10, pp. 1194–1200. The text was submitted by the authors in English.     

Adsorption of organic molecules on electrodes: 2005 Frumkin Memorial Medal Award lecture

This Award lecture, delivered on the occasion of the presentation of the 2005 Frumkin Memorial Medal to the author, consists of two parts: a memorial section and a scientific section. In the scientific section the successive development of models within Frumkin theory of adsorption of organic molecules on electrodes are presented. In particular, (i) the versions of theory taking into account the dependence of attraction constant in adlayer on the electrode potential, (ii) generalization of Frumkin’s, Parsons’s and Hansen’s models, (iii) model for coadsorption of two compounds, and (iv) model taking into account the diffuse part of the double layer are reported. Published in Russian in Elektrokhimiya, 2007, Vol. 43, No. 3, pp. 259–267. The text was submitted by the author in English.