H. W. Bakhuis Roozeboom (, October 24, 1854 – February 8, 1907) was a Dutch chemist who studied

phase behaviour Polymorphism in biophysics is the ability of lipids to aggregate in a variety of ways, giving rise to structures of different shapes, known as "phases". This can be in the form of sphere of lipid molecules (micelles), pairs of layers that face on ...

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, statistica ...

Education and career

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

Alkmaar Alkmaar () is a city and municipality in the Netherlands, located in the province of North Holland, about 30 km north of Amsterdam. Alkmaar is well known for its traditional cheese market. For tourists, it is a popular cultural destination. The ...

in the

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

. 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''; nl, Universiteit Leiden) is a public research university in Leiden, Netherlands. The university was founded as a Protestant university in 1575 by William, Prince of Orange, as a reward to the city of Le ...

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 In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a se ...

s. J. D. van der Waals introduced him to the theoretical works of

J. Willard Gibbs Josiah Willard Gibbs (; February 11, 1839 – April 28, 1903) was an American scientist who made significant theoretical contributions to physics, chemistry, and mathematics. His work on the applications of thermodynamics was instrumental in t ...

on the

phase rule In thermodynamics, the phase rule is a general principle governing "pVT" systems, whose thermodynamic states are completely described by the variables pressure (), volume () and temperature (), in thermodynamic equilibrium. If is the number of d ...

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, nl, Universiteit van Amsterdam) is a public research university located in Amsterdam, Netherlands. The UvA is one of two large, publicly funded research universities in the city, the other being ...

, 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, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws ...

, in which he studied the equilibrium of multiple-phase systems. The theoretical foundations for this were laid by J. Willard Gibbs with his

, but Roozeboom would be the one to apply the theory and demonstrate its usefulness. He is mainly remembered for his melting

phase diagrams A phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions (pressure, temperature, volume, etc.) at which thermodynamically distinct phases (such as solid, liquid or gaseous ...

of metal

alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductili ...

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 sc ...

. 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 (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is distinguishable from i ...

substances, clarified how to distinguish the different types of crystalline

racemate In chemistry, a racemic mixture, or racemate (), is one that has equal amounts 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 racemates. ...

s and predicted how mixtures of

enantiomer In chemistry, an enantiomer ( /ɪˈnænti.əmər, ɛ-, -oʊ-/ ''ih-NAN-tee-ə-mər''; from Ancient Greek ἐνάντιος ''(enántios)'' 'opposite', and μέρος ''(méros)'' 'part') – also called optical isomer, antipode, or optical anti ...

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 ( nl, Koninklijke Nederlandse Akademie van Wetenschappen, abbreviated: KNAW) is an organization dedicated to the advancement of science and literature in the Netherlands. The academy is housed ...

. 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 University of Amsterdam faculty People from Alkmaar