Chemistry

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Chemistry was one of the foundation disciplines in an Institute devoted initially to research in nuclear energy. Laboratories for analytical chemistry and for fluorination and preparation of uranium hexafluoride were established, and these two general areas are still actively pursued today. In the fifties the first flame atomic spectrometer and the first mass spectrometer in Yugoslavia were built on site, and the use of atomic absorption and emission spectroscopy for determining metals was introduced. Work in the fluorination laboratory concentrated first on the production of elemental fluorine and on management of the demanding experimental techniques for work with this aggressive element. Investigations connected with ceramic nuclear fuel based on uranium dioxide followed soon after.

From the beginning, much of the Institute's chemical research has had direct applications in view, and this is reflected in the number of contracts with Slovenian industry. It has resulted in the development of technologically demanding products such as varistors, microwave resonators, capacitors, PTC resistors, sensors, ferrites, rare earth permanent magnets, hybrid circuits, and mechanically resistant ceramics. Co-operation with industrial partners in Slovenia includes the production of mineral fibres for thermal isolation, and the manufacture of glass. Among other European industrial partners there is a cooperation with the MAN Roland Druckmaschinen company on the development of ferroelectric cylinders for a new form of printing.


Evolvement of research areas


CHEMISTRY

Today chemistry based research in the Institute follows four main directions. In the field of synthetic chemistry of inorganic fluorine compounds, synthesis of the then unknown xenon hexafluoride and photosynthesis of krypton difluoride in liquefied fluorine are important landmarks. The latter is still valid today as the most successful method for the synthesis of krypton difluoride. One hundred fold greater quantities can be prepared than with other methods, resulting in extensive investigations of high energy oxidizers. This has led, in collaboration with the University of California at Berkeley, to the synthesis and characterization of a series of higher binary fluorides of silver, copper and nickel - a highly significant achievement. Fluorination reactions of organic molecules are also studied, including an important long-term collaboration with BASF investigating the fluorination of polymeric materials.

The Institute is known internationally for its contribution to the processing of ceramics and specialized alloys. The most important scientific achievements include the synthesis of microwave dielectric ceramics and establishing a correlation between their structure and properties, the explanation of the positive temperature coefficient of resistance for ferroelectric ceramics and a contribution to understanding ceramic toughness. Recently much effort has been put into the synthesis of nanocrystalline particles, into ferroelectric thin films for micro-sensors and micro-actuators, and into bio-compatible materials.

Protection of the environment and the development of clean, environment-friendly technologies rank high in the chemists' concerns. Desulphurization of chimney gases, selective thermal decomposition of nitrogen oxides, environment friendly incineration of solid and liquid wastes and the use of chemical monitoring in the management of technological processes are typical examples of helping to minimize industrial pollution. More basic research includes studies of catalytic reactions associated with environmental pollution. An important thrust is the development and use of analytical methods for determining elements and their chemical species, radionuclides and organic pollutants in the biosphere. By measuring stable isotopes, sources of pollution can be detected and the paleoclimatic background can be studied. The results are used primarily for modelling natural processes and for evaluating influences of industrial intervention on the environment.

Industrial and health associated projects include studies of the processes of corrosion and of passivation of technologically important metals and alloys, such as in solid protection layers, metal and polymer orthopaedic implants, and primary zinc batteries.


J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia, Telephone: +386 1 477 39 00, Fax: +386 1 251 93 85
info@ijs.si