Hendrik Willem Bakhuis Roozeboom (; October 24, 1854 – February 8, 1907) was a Dutch chemist who studied phase behaviour in

physical chemistry Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mech ...

Education and career

Bakhuis Roozeboom (originally "Bakhuys Roozeboom") was born in

Alkmaar Alkmaar () is a List of cities in the Netherlands by province, city and List of municipalities of the Netherlands, municipality in the Netherlands, located in the Provinces of the Netherlands, province of North Holland. Alkmaar is well known fo ...

in the

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

. Financial difficulties did not allow him to directly pursue a university education, and he left school to work in a chemical factory for some time. Due to support from his mentor, J. M. van Bemmelen, he became an assistant at the

University of Leiden Leiden University (abbreviated as ''LEI''; ) is a public research university in Leiden, Netherlands. Established in 1575 by William, Prince of Orange as a Protestant institution, it holds the distinction of being the oldest university in the Neth ...

in 1878, which enabled him to start his academic education there. In 1881 he became a teacher at a girls school, and in 1884 he obtained his PhD with works on the

hydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...

s of

acid An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis ...

s. J. D. van der Waals introduced him to the theoretical works of J. Willard Gibbs on the phase rule which so far had little experimental verification in chemistry, prompting him to start a lifelong research program on phase equilibria. In 1896, he became professor for chemistry at the

University of Amsterdam The University of Amsterdam (abbreviated as UvA, ) is a public university, public research university located in Amsterdam, Netherlands. Established in 1632 by municipal authorities, it is the fourth-oldest academic institution in the Netherlan ...

, where he died on February 8, 1907. Bakhuis Roozeboom's main work was in the field of

thermodynamics Thermodynamics is a branch of physics that deals with heat, Work (thermodynamics), work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed b ...

, in which he studied the equilibrium of multiple-phase systems. The theoretical foundations for this were laid by J. Willard Gibbs with his phase rule, but Roozeboom would be the one to apply the theory and demonstrate its usefulness. He is mainly remembered for his melting phase diagrams of metal

alloy An alloy is a mixture of chemical elements of which in most cases at least one is a metal, metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Metallic alloys often have prop ...

s, i.e. studying how mixtures of metals melt depending on the relative amounts of the components, which is important for

metallurgy Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys. Metallurgy encompasses both the ...

. Roozeboom also was the first to plot ternary phase equilibria in two-dimensional plots that were taken as vertical or horizontal slices from the three-dimensional solid diagrams. These are termed, respectively, isopleths and isotherms. He also contributed to the science of

chiral Chirality () is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek language, Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is dist ...

substances, clarified how to distinguish the different types of crystalline

racemate In chemistry, a racemic mixture or racemate () is a mixture that has equal amounts (50:50) of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as r ...

s and predicted how mixtures of

enantiomer In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities whi ...

s behave in a heterogeneous system of solid and solution. In 1890 Bakhuis Roozeboom became a member of the

Royal Netherlands Academy of Arts and Sciences The Royal Netherlands Academy of Arts and Sciences (, KNAW) is an organization dedicated to the advancement of science and literature in the Netherlands. The academy is housed in the Trippenhuis in Amsterdam. In addition to various advisory a ...

. Roozeboom succeeded J. H. van't Hoff at the University of Amsterdam. In 1904, he published the first volume and first part of the second volume of the multi-volume treatise on heterogeneous equilibria entitled ''Die Heterogenen Gleichgewichte von Standpunkte des Phasenlehre'' "Heterogeneous Equilibria from the Phase Rule Viewpoint." In 1911, the Bakhuis Roozeboom Fund was established in his honour; every four years it awards a gold medal for research on phase theory.

References

BAKHUYS ROOZEBOOM, Hendrik Willem (1854-1907)
in the Biographical Dictionary of the Netherlands: 1880-2000 (in Dutch) {{DEFAULTSORT:Bakhuis Roozeboom, Hendrik Willem 1854 births 1907 deaths Dutch physical chemists Leiden University alumni Members of the Royal Netherlands Academy of Arts and Sciences Academic staff of the University of Amsterdam People from Alkmaar