STUDIA UNIVERSITATIS BABES-BOLYAI, CHEMIA, XLIX, 1, 2004

            The brilliant scientist Professor Zsako Ioan (Janos) was born on January 22, 1926, and died on August 7, 2001, in his natal town Cluj-Napoca.

            He was educated at “Bolyai” University of Cluj-Napoca, Faculty of Sciences, Chemistry Department, where he graduated as a chemist in 1948. He studied for his Ph.D. with the famous scientist Academician Professor Raluca Ripan in the field of complex protolytic equilibria in aqueous solutions, particulary about physico – chemical investigations of phosphoric acids and his Ph.D. degree was awarded in 1956.

            As well as being a world-class scientist, he was a great teacher. He was appointed assistent in 1950 and lecturer in 1955 at “Bolyai” University, where he taught students in Hungarian language. In 1959, when “Bolyai” University was united with “Babes” University (with Romanian language for the students instruction), he was nominated associated professor (reader) at the “Babes – Bolyai” University, where he taught in both Romanian and Hungarian languages. In 1990 he was appointed full professor at the same university in Cluj-Napoca, physical chemistry department. Later, in 1991, he was retired and nominated as a consultant professor remaining active in research and teaching activities as well as being supervisor for Ph.D. students until his death.

            He taught general chemistry and physical chemistry, such as kinetics, electrochemistry, chemical structure, thermodynamics, and quantum chemistry both in Romanian and Hungarian languages. He also taught courses abroad, e.g., chemical structure, quantum chemistry and quantum mechanics in French language at the University in Constantine, Alger (1972 -1976). Then, in 1992, he was invited professor at Polytechnic Institute in Budapest, Hungary, for two months and had a special course of quantum chemistry.

            As recognition of his accomplishments, in 1990, he received the honor to be a supervisor and lead students for Ph.D. degree in chemistry, specialty in physical chemistry. Many of his Ph.D. students or co-workers became leaders in their fields at the forefront of science and technology.

            He was a world-renowned physico-chemist for his remarkable scientific achievements combined with his personal integrity. In this context, we would like to recall some of his major scientific interests.

            A series of studies of non-isothermal kinetics in homogeneous and heterogeneous systems was carried out and he developed kinetic theories, new calculation methods, and novel experimental methods for thermogravimetry, particulary, for the thermal decomposition of coordinative combinations with an emphasis on the kinetic effect of compensation. For outstanding achievements he was nominated in 1971 as a member in the Editorial Advisory Board for the Journal of Thermal Analysis, Budapest, Hungary. Then, he initiated and developed a scientific collaboration between “Babes-Bolyai” University of Cluj-Napoca and Technical University of Budapest, Hungary. For outstanding work in science and for the Journal of Thermal Analysis his 75^th birthday was celebrated at the Hungarian Academy of Sciences, when a scientific meeting was dedicated for that event.

            Important contributions also include: kinetic studies of ligand-exchange reactions and of protolytic equilibria, IR spectra of coordinative combinations and the calculation of force constants, UV-VIS spectra, protolytic equilibria in bulk solutions, acidity constants using potentiometric and spectro-photometric methods.

            Further, an outline of his remarkable work with major importance in physical chemistry of interfaces and surface science will be given here.

            He developed the surface thermodynamics and described phase equilibria, complex phase diagrams in mixed Langmuir monolayers, compression isotherms of Langmuir and Gibbs monolayers by using molecular models, molecular packing in the two-dimensional lattice, and molecular conformational transitions. A novel approach to the surface protolytic equilibria was developed and the interfacial pH was determined with large applications in membrane science.

             A series of studies of molecular associations at interfaces with the formation of supramolecular functional associations was also carried out. The developed thermodynamic theory of supramolecular associations in interfacial solutions opens a new horizon to the modern physical and biophysical chemistry and explains the formation of complex supramolecular associations in monolayers at fluid interfaces, liquid/gas and liquid/liquid, with large applications in biomedicine, cosmetics, pharmaceutics, material science and micro-electronics.

            The work done on systems containing Langmuir bio-active monolayers and anesthetics, such as procaine, dibucaine and tetracaine, and Gerovital formula, is directly applicable to studies of some diseases of the nervous system, such as Alzheimer’s and Parkinson’s disease. The effects of procaine, in very specific formulations, on Langmuir monolayers can be substantially correlated with its interfacial effects on the neuronal membrane and they might play an important role in the molecular treatment of these diseases. This scientific research has generated effective therapeutic modalities to treat neurological and aging disorders and was developed in collaboration with well known scientists, Professor Petre T. Frangopol, Professor David A. Cadenhead from State University of New York State (SUNY) at Buffalo, USA, Professor Peter J. Quinn from University of London, UK, and Professor Traianos Yupsanis from Aristotle University of Thessaloniki, Greece. The kinetic models developed for the adsorption of various surfactants at fluid interfaces and for the collapse mechanisms and relaxation processes within Langmuir monolayers represent a key step to describe various industrial phenomena including emulsions, lubrication, drug delivery systems, pharmaceuticals, cosmetics, food industry, micro- and nano-technology and oil recovery. These accomplishments led to the development of new membrane models and selective methods in biophysics of membranes and thin films and in colloid chemistry.

            We would like to mention that many outstanding contributions, in the field of “physical chemistry of interfaces”, were developed jointly with the eminent scientist Professor Emil Chifu (In Memoriam, Studia Universitatis Babes-Bolyai, Chem., XLIII, 1-2, 1998, pp. 3-17). Their application to chemistry, physics and biology leads to the creation of new original theoretical tools in this inter- and multi-disciplinary enterprise and represents major achievements in modern science. For exceptional original contributions in this field- in 1983- he received jointly with Professor Emil Chifu and other colleagues the prestigious Gheorghe Spacu award of the Romanian Academy of Sciences on “The physical and chemical properties of thin films” with important applications in the space technology of liquids and in the modeling of biological surfaces.

            He published over 270 scientific papers in peer review journals (the attached List of publications) with a cumulative citation index greater than 1500. Many of them cited over 30 times, and another one cited more than 200 times, which is an unusual event for the citation of original papers in the field of physical chemistry. For major contributions to science and technology in 1993, he was elected vice-president of the Thermal Analysis and Calorimetry Section at the Romanian Academy of Sciences, Bucharest.

            He was a member of the Romanian Academy of Sciences, the Hungarian Academy of Sciences and the Romanian Society of Colloids and Surface Science.

            He elaborated single or in collaboration eight scientific books, in Romanian and in Hungarian languages. Two of them, namely, Physical Chemistry: The structure of atoms and molecules, 1973, and Symmetry and Molecular Structure, 1998, (the attached List of Publications), are used frequently by students not only in Cluj-Napoca but all over the country, at all university centers in Romania. He is also co-outhor at an Encyclopedia for Chemistry in Hungarian language. 

            He was also interested in philosophical problems raised from natural sciences and he published papers in Korunk Review. He also published articles for the community science in newspapers. In 1990 he was nominated the editor in chief of Firka Review, for Section of physical chemistry and informatics, edited for high school level by the Hungarian Society for Science and Technology in Transylvania.

             He was a private but generous person with consideration for others reflected in his research group as well as in his home.

            We would like to thank his wife Magdolna Zsako and to colleagues and friends Aurora Mocanu and Iosif Albu for valuable discussion during the preparation of this obituary.