Jaroslav Heyrovský

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Jaroslav Heyrovský
Grave in the Vyšehrad cemetery in Prague

Jaroslav Heyrovský (born December 20, 1890 in Prague ; † March 27, 1967 there ) was a Czech physical chemist . His most significant contribution to science was the development of polarography . For this he received the Nobel Prize in Chemistry in 1959 .

Life

Jaroslav Heyrovský was the son of a professor of law. In 1909 he studied physics, mathematics and chemistry at the University of Prague. Between 1910 and 1914 he continued his studies at University College in London. In 1913 he received a Bachelor of Science degree from Sir William Ramsay . In the following years of the First World War he was drafted as a soldier in the Austro-Hungarian Army. In the medical service he was employed as a chemist in radiology. Nevertheless, he continued his studies in order to obtain his doctorate in Prague in 1918. In 1920 he completed his habilitation at the University of Prague. He then worked there as a lecturer in physical chemistry. In London in 1921 he was awarded the degree of Doctor of Science (D.Sc.). Heyrovský was appointed associate professor at Prague University in 1922 and full professor of physical chemistry in 1926. From 1950 he was head of the newly founded polarography institute at Charles University in Prague . This facility later became part of the Heyrovský Institute for Polarography of the Academy of Sciences of the Czechoslovakia . The institute bears his name to this day.

The Heyrovský medal named after him is awarded for special achievements in the field of electrochemistry . Heyrovský was elected to the American Academy of Arts and Sciences in 1933 . From 1956 he was a member of the German Academy of Sciences Leopoldina . In 1955 he was awarded an honorary doctorate from the Technical University of Dresden .

His long-time assistant was Rudolf Brdička .

In 1985 the Heyrovsky lunar crater was named after him, as was the asteroid (3069) Heyrovsky in 1990 .

plant

Invention of polarography

Professor Kucera was present during the defense of his doctoral thesis in 1918 and aroused Heyrovský's interest in the dripping mercury electrode. These were used to investigate electrocapillary forces . To do this, the experimenter either weighed the fallen mercury drops or determined the time of the drop. The values ​​were plotted in a diagram against the electrochemical potential applied in each case . At the end of 1921 Heyrovský had the idea of ​​measuring the electrical current that flowed through the electrochemical cell and thus through the dripping mercury electrode. These experiments were only successful when a particularly sensitive mirror galvanometer was used. Only these instruments were then able to measure the tiny electrolysis currents (nA to µA) at the mercury drop electrode depending on the applied potential. From 1922 he and his colleagues recorded such current-voltage curves by hand. It was found that the electrolysis of dissolved chemical substances resulted in stepped signals. The height of the step depended on the concentration. For example, it was still possible to detect metal ions in the trace range (10 ... 100 µmol / l ). The position of the step on the potential axis, however, was characteristic of the reacting substance. This electrochemical analysis method of polarography using the mercury drop electrode spread rapidly throughout the world in the following decades. It enables quantitative and qualitative analyzes of substances that can be converted at the mercury electrode.

Further development of the polarographic method

Heyrovský developed the electromechanical polarograph with his colleague Shikato from 1924. This device was able to automatically record polarograms and thus made polarographic experiments much easier. This electromechanical instrument type dominated for the next 40 years or so. After that, electronic potentiostats came into use that were coupled to the mercury drop electrode. Today a modern polarograph is completely computer controlled. From 1926 Heyrovský published the first publications on the new method. In the following years he devoted himself to theoretical studies on diffusion-limited currents and mechanisms of electrode reactions. He also developed the mercury beam electrode and alternating current polarography. With the latter, an alternating voltage is superimposed on the uniformly variable voltage, with the alternating current component being measured as an analytical signal .

Jaroslav Heyrovský also contributed to the dissemination of his method through books. These easy-to-understand works are devoted to both the theoretical basics and practical handling up to concrete analysis regulations.

Publications

  • LR Sherman: Jaroslav Heyrovský (1890-1967) . In: Chemistry in Britain . December 1990, pp. 1165 - 1167.

Web links

Commons : Jaroslav Heyrovský  - collection of pictures, videos and audio files

Individual evidence

  1. Member entry of Jaroslav Heyrovský at the German Academy of Natural Scientists Leopoldina , accessed on October 12, 2012.
  2. Honorary doctorates of the Faculty of Mathematics and Natural Sciences ( Memento of the original from January 28, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. of the TU Dresden  @1@ 2Template: Webachiv / IABot / tu-dresden.de
  3. Jaroslav Heyrovský in the Gazetteer of Planetary Nomenclature of the IAU (WGPSN) / USGS
  4. Jaroslav Heyrovský at the IAU Minor Planet Center (English)