文档介绍：Johannes Diderik van der Waals
1837 - 1923
Awarded the Nobel Prize for Physics in 1910
At a time when the existence of molecules was still held in doubt by at least some respectable
scientists, Johannes Diderik van der Waals developed a model of molecular interactions. His
equation of state had the basic features needed for the understanding of a great variety of
phenomena occurring in fluids and fluid mixtures. He received the Nobel Prize in 1910. He is
considered the founder of molecular science. His ideas are
Van der Waals was born in Leiden, Netherlands, the son of a carpenter and the eldest of ten used in the
children. After finishing middle school at the age of fifteen, he started working as an apprentice
elementary school teacher. For over 20 years, van der Waals climbed through the teachers’ranks oil industry
by taking evening classes and, eventually, university repairing the deficiencies of
his early schooling, he was allowed to defend his . thesis in 1873. He was a Professor of
Physics at the University ofAmsterdam, Netherlands, from 1877 to 1908.
The thesis was immediately recognised as very significant: James Clerk Maxwell learned
Dutch in order to read it. Van der Waals considered the molecules as hard spheres surrounded
by a sphere of attraction. With this model, he could describe the properties of both gases and
liquids. A liquid and its vapour are separated by an interface, and the liquid is much denser than
the vapour. Van der Waals showed, however, that only below its ‘critical point’ may a gas be
this point, the transition from vapour-like to liquid-like densities is continuous,
without the appearance of an interface. By expressing fluid properties in terms of the critical-
point parameters, Van der Waals obtained the law of corresponding states which maps properties
from one fluid to another. This law allowed him to predict the critical point of helium, which, in
turn, enabled his friend,