Christian Friedrich Schönbein

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Christian Friedrich Schönbein
Christian Friedrich Schönbein
Christian Friedrich Schönbein
Born October 18, 1799(1799-10-18)
Metzingen, Germany
Died August 29, 1886 (aged 86)
Baden-Baden, Germany
Residence Germany, Switzerland
Nationality German
Institutions University of Basel
Known for fuel cell, ozone, guncotton

Christian Friedrich Schönbein (October 18, 1799 – August 29, 1868) was a German-Swiss chemist who is best known for his studies of fuel cells (1838) and his discoveries of guncotton and ozone.

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[edit] Life

Schönbein was born at Metzingen, Swabia. Around the age of 13 he was apprenticed to a chemical and pharmaceutical firm at Böblingen. Through his own efforts, he acquired sufficient scientific skills and knowledge that he asked for, and received, an examination by the professor of chemistry at Tübingen. Schönbein passed the exam and, after a series of moves and university studies, he eventually acquired a position at the University of Basel in 1828, becoming a full professor in 1835. He remained there until his death in 1868, and was buried in Basel.[1]

[edit] Ozone

It was while doing experiments on the electrolysis of water at the University of Basel that Schönbein first began to notice a distinctive odor in his laboratory.[2] This smell gave Schönbein the clue to the presence of a new product from his experiments. Because of the pronounced smell, Schönbein coined the term ‘ozone’ for the new gas, from the Greek word ‘ozein’, meaning ‘to smell’. Schönbein described his discoveries in publications in 1840.[3] He later found that the smell of ozone was similar to that produced by the slow oxidation of white phosphorus.[4]

The ozone smell Schönbein detected is the same as that occurring in the vicinity of a thunderstorm, an odor that indicates the presence of ozone in the atmosphere.

[edit] Explosives

Although his wife had forbidden him to do so, Schönbein occasionally experimented at home in the kitchen. One day in 1845, when his wife was away, he spilled a mixture of nitric acid and sulfuric acid. After using his wife's cotton apron to mop it up, he hung the apron over the stove to dry, only to find that the cloth spontaneously ignited and burned so quickly that it seemed to disappear. Schönbein, in fact, had converted the cellulose of the apron into nitrocellulose; the nitro groups (added from the nitric acid) served as an internal source of oxygen, and when heated the cellulose was completely and suddenly oxidized.

Schönbein recognized the possibilities of the new compound. Ordinary black gunpowder, which had reigned supreme in the battlefield for the past 500 years, exploded into thick smoke, blackening the gunners, fouling the cannon and small arms, and obscuring the battlefield. Nitrocellulose was a possible "smokeless powder", and from its potential as a propellant for artillery shells, it received the name guncotton.

Attempts to manufacture guncotton for military use failed at first because the factories had a tendency to explode. It was not until 1891 that James Dewar and Frederick Augustus Abel managed to compound guncotton into a safe mixture, called cordite because it could be pressed into long cords.

[edit] Selected writings

[edit] References

  1. ^ Oesper, Ralph E. (1929). "Christian Friedrich Schönbein". Journal of Chemical Education 6: 432 – 440. 
  2. ^ Schönbein, C. F. (1838-1840). "Lecture of March 13, 1839.". Ber. Verh. Nat. Ges. Basel 4: 58. 
  3. ^ Schönbein, C. F. (1840). "On the Odour Accompanying Electricity and on the Probability of its Dependence on the Presence of a New Substance". Philosophical Magazine 17: 293 – 294. 
  4. ^ See, for example, Schönbein, C. F. (1844). "On the Production of Ozone by Chemical Means". Philosophical Magazine 24: 466 – 467. 

[edit] Further reading

  • Brown G. I. The Big Bang: A History of Explosives, Sutton Publishing; 1998 (ISBN 0750937920)