Photo from the Nobel Foundation archive.
Richard Adolf Zsigmondy
The Nobel Prize in Chemistry 1925
Born: 1 April 1865, Vienna, Austrian Empire (now Austria)
Died: 24 September 1929, Göttingen, Germany
Affiliation at the time of the award: Goettingen University, Göttingen, Germany
Prize motivation: "for his demonstration of the heterogenous nature of colloid solutions and for the methods he used, which have since become fundamental in modern colloid chemistry."
Richard Zsigmondy received his Nobel Prize one year later, in 1926.
Prize share: 1/1
In chemistry very small particles that are finely dispersed in another substance are called colloids. Colloid particles are so small that they cannot be observed in a regular microscope. In 1902 Richard Zsigmondy introduced an idea that led to the ultramicroscope, which makes it possible to observe very small particles by illuminating the preparation being studied in a direction that is perpendicular to the viewing angle. Richard Zsigmondy used the ultramicroscope to show the heterogeneous structure of colloids, which contain particles that are small but vary in size.