Israel Epelboin 1916–1980

J Electroanal. Chem., 111 (1980) 1--3 © Elsevier Sequoia S.A., L a u s a n n e - - P r i n t e d in The N e t h e r l a n d s

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Obituary ISRAEL EPELBOIN 1916--1980

I. Epelboin was born in 1916 at Hotin (Romania). His higher education was completed in France. His first degree (Licence in physical and mathematical sciences) was obtained in the Faculty of Sciences at Grenoble in 1939. He t h e n entered the Ecole Sup~rieure d'Electricit~ of Paris and in 1940 obtained the title of Engineer. In 1944, he joined the CNRS (Centre National de la Recherche Scientifique) where he remained for the rest of his life. However, his first work was directed from 1940 by F. Bedeau towards the study of the permeability o f ferromagnetic materials both metallic and oxidic powders, under an alternating field. This work was to be the origin of the main directions introduced by Epelboin after completion of his thesis (1946). In fact, the superposition of alternating current was to be for him the chosen m e t h o d for the determination of the dielectric properties of concentrated solutions and for the measurements of electrode impedance. In addition, in the course of his thesis work, he had been led to use electrolytic polishing to obtain a progressive thinning of ferro-nickel tapes free from mechanical perturbations. This was to be the origin of the introduction of electrochemical problems into his activities. This development was clearly facilitated by the fact that, at t h a t time, Epelboin began to build up a team in the laboratory of Physics Teaching directed by E. Darmois. He then u n d e r t o o k a long series of studies on the mechanism o f electrolytic polishing and on the development of the state o f the surface of metals and semiconductors as a function o f electrochemical parameters. This led him to construct apparatus allowing a rapid study of the best polishing conditions and to propose new electrolytes based on alkali metal perchlorates. Epelboin also showed how electrolytic polishing could be used to determined the dissolu-

tion valency of m a n y metals, semiconductors and alloys. The interface where the adsorption of anion leads to high anodic voltages was particularly favourable for the passage of metallic ions into solution in the monovalent state. The progressive increase in the personnel of his laboratory allowed I. Epelboin to introduce new research themes from the years 1955--1960: study of the superheating of gallium and the discovery of new phases; analysis of the dielectric properties of concentrated electrolytes. At the same time, he started his first work on polarography, electrocrystallization and corrosion of metals. The originality of his work lay in the joint use of the methods of electrochemical kinetics and the methods of characterization of materials such as X-rays and the electron miscroscope. Epelboin was among the first to use the methods of potentiostatic and potentiodynamic recording of polarization curves. He was also one of the most enthusiastic advocates of the use of impedance methods for the study of electrochemical kinetics. Thanks to recent expemmental advances and to the construction in his laboratory of potentiostats adapted to transfer function analysers, impedance could be measured over a very wide range of frequency. In recent years the mechanism of electrocrystalhzatlon of metals like nickel, zinc and silver, the anodic dissolution and passlvation of iron and its alloys could be determined. At the same time work was started to try to relate the conditions of the preparation of the deposits, their growth mechanism and their structure. Epelboin equally encouraged research in his laborat o r y which established the links between the kinetics of dissolution reactions, mass transport and the structure of materials in the initatlon and propagation of localized corrosion phenomena. I. Epelboin was one of those who contributed to the promotion of the use of the rotating disc electrode in electrochemical engineering by showing particularly how it added to the knowledge of mass transport by turbulent diffusion. In this area, he showed the great interest of local measurement of mass flux by the electrochemical method, which allowed an original approach to side wall phenomena in fluid mechanics. In recent years, thanks to these techniques, he had made advances in our understanding of the phenomena of the reduction of h y d r o d y n a m i c friction in the presence of linear, flexible high polymers. I. Epelboin was also an advocate of optical methods for the in situ study of processes at the metal--electrolyte interface. From 1955 he had been able to observe the various stages in the change of the surface state during electrolytic polishing using optical microscopy; with the same method, he determined the nature of the layers formed in the corrosion of iron and nickel in sulphate medium. Later, the use of spectroreflectometry and electroreflectance enabled him to identify and study the properties of the very thin layers formed in the anodic oxidation and the passivation of metals. In 1966, Epelboin's laboratory obtained from the CNRS the status of "Groupe de Recherche" and it t o o k the title o f "Physics o f Liquids and Electrochemistry". Shortly afterwards a contract of association was signed with the Pierre et Marie Curie University within which the laboratory is situated. I. Epelboin has left a very substantial legacy: more than 320 publications and communications between 1943 and 1980. A large number of pupils were trained in his laboratory. Since 1948, 144 DiplSmes d'Etudes Superieures, Theses de 3°cycle, d'Universit~ d'Etats, have been submitted. The tradition of

Darmois' laboratory of being very open to foreigners was continued and Epelboin welcomed and directed the work of students coming from all the continents; their tributes to him after his death have been extremely moving. I. Epelboin was a member o f m a n y learned societies both French and international. Since 1955, he was a very active member of CITCE, (now ISE) and several years ago he was one o f the Vice-Presidents. He went regularly to the meetings and brought much enthusiasm to them. Many will still remember the vigorous discussions with the late Professor Cavallaro during one of the most successful meetings, in Rome in 1962. Epelboin was also a prominent member of the IUPAC Electrochemistry Commission until 1979. Finally, he was a member of the Editorial Committee o f several scientific journals including JEC. To everyone who knew him, I. Epelboin leaves a m e m o r y of a warm and enthusiastic man. During future scientific meetings the electrochemical community will be able to appreciate the gap t h a t his passing has left. M. F R O M E N T Meudon-Bellevue