Georges Friedel
Encyclopedia
Georges Friedel is a city and commune in eastern France, close to the Swiss and German borders. With a population of 110,514 and 278,206 inhabitants in the metropolitan area in 2006, it is the largest city in the Haut-Rhin département, and the second largest in the Alsace region after...
; died 11 December 1933 in Strasbourg
Strasbourg
Strasbourg is the capital and principal city of the Alsace region in eastern France and is the official seat of the European Parliament. Located close to the border with Germany, it is the capital of the Bas-Rhin département. The city and the region of Alsace are historically German-speaking,...
) was a French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
mineralogist
Mineralogy
Mineralogy is the study of chemistry, crystal structure, and physical properties of minerals. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization.-History:Early writing...
and crystallographer
Crystallography
Crystallography is the experimental science of the arrangement of atoms in solids. The word "crystallography" derives from the Greek words crystallon = cold drop / frozen drop, with its meaning extending to all solids with some degree of transparency, and grapho = write.Before the development of...
.
Life
Georges was the son of the famous chemist Charles FriedelCharles Friedel
Charles Friedel was a French chemist and mineralogist. A native of Strasbourg, France, he was a student of Louis Pasteur at the Sorbonne...
. Georges' grandfather was Louis Georges Duvernoy who held the chair in comparative anatomy
Comparative anatomy
Comparative anatomy is the study of similarities and differences in the anatomy of organisms. It is closely related to evolutionary biology and phylogeny .-Description:...
from 1850 to 1855 at the Muséum national d'histoire naturelle
Muséum national d'histoire naturelle
The Muséum national d'Histoire naturelle is the National Museum of Natural History in Paris, France.- History :The museum was formally founded on 10 June 1793, during the French Revolution...
.
Georges studied at the École Polytechnique
École Polytechnique
The École Polytechnique is a state-run institution of higher education and research in Palaiseau, Essonne, France, near Paris. Polytechnique is renowned for its four year undergraduate/graduate Master's program...
in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
and the École Nationale des Mines in St. Etienne, and was a student of François Ernest Mallard. In 1893 he obtained a professorship at the École Nationale des Mines, the director of which he would later become. After the First World War, he returned as a professor at the University of Strasbourg
University of Strasbourg
The University of Strasbourg in Strasbourg, Alsace, France, is the largest university in France, with about 43,000 students and over 4,000 researchers....
in Alsace
Alsace
Alsace is the fifth-smallest of the 27 regions of France in land area , and the smallest in metropolitan France. It is also the seventh-most densely populated region in France and third most densely populated region in metropolitan France, with ca. 220 inhabitants per km²...
. Due to ill health, he took early retirement in 1930, and died in 1933. He was married with five children.
Scientific works
Like his teacher Mallard, Friedel concerned himself with the theories of Auguste BravaisAuguste Bravais
Auguste Bravais was a French physicist, well known for his work in crystallography...
, the founder of crystallography. Friedel was able to demonstrate the theoretical ideas of Bravais (the Bravais lattice) with the help of x-ray diffraction experiments on crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
s, and so provide the physical basis therefore. One of his most important discoveries was the law that now bears his name.
Friedel's salt
In 1897, Georges Friedel synthesised and identified calcium chloroaluminateFriedel's salt
Friedel's salt is an anion exchanger mineral belonging to the family of the layered double hydroxides . It has affinity for anions as chloride and iodide and is capable to retain them to a certain extent in its crystallographical structure....
which received his name. Georges Friedel also synthesised calcium aluminate in 1903 in the framework of his work on the macle
Macle
Macle is a term used in crystallography. It is a crystalline form, twin-crystal or double crystal .Macle is an old French word, a heraldic term for a voided lozenge...
s theory.
Mesomorphic states of matter
The presumption that solid and liquid are adjacent states of matter was undercut by Friedrich ReinitzerFriedrich Reinitzer
Friedrich Richard Reinitzer was an Austrian botanist and chemist. In late 1880s, experimenting with cholesteryl benzoate, he discovered properties of liquid crystals ....
in 1888 when he noted a cloudy mesophase
Mesophase
In physics, a mesophase is a state of matter intermediate between liquid and solid. Gelatin is a common example of a partially-ordered structure in a mesophase...
of cholesteryl benzoate
Cholesteryl benzoate
Cholesteryl benzoate, also called 5-cholesten-3-yl benzoate, is an organic chemical, an ester of cholesterol and benzoic acid. It is a liquid crystal material forming cholesteric liquid crystals with helical structure....
between 145.5°C and 178.5°C. The subject was taken up in Germany, and in 1907 also in France by George Friedel and François Grandjean, as they described the "focal conic liquid".
Friedel contributed his Mesomorphic States of Matter to the Annales des Physiques
Annales de chimie et de physique
Annales de chimie et de physique is a scientific journal that was founded in Paris, France, in 1789 under the title Annales de chimie. One of the early editors was the French chemist Antoine Lavoisier. In 1815, it became the Annales de chimie et de physique, and was published under that name for...
in 1922. This two-hundred-page work established much of the current terminology in mesophase
Mesophase
In physics, a mesophase is a state of matter intermediate between liquid and solid. Gelatin is a common example of a partially-ordered structure in a mesophase...
physics. First, the nematic phase he characterized as having microscopic threads (these threads are today interpreted as disclination
Disclination
A disclination is a line defect in which rotational symmetry is violated. In analogy with dislocations in crystals, the term, disinclination, for liquid crystals first used by F. C. Frank and since then has been modified to its current usage, disclination.It is a defect in the orientation of...
s in the director-field in the mesophase). Second, Friedel coined the term smectic phase for a layered mesophase having the structure of neat soap
Soap
In chemistry, soap is a salt of a fatty acid.IUPAC. "" Compendium of Chemical Terminology, 2nd ed. . Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford . XML on-line corrected version: created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN...
. Third, Friedel use the term cholesteric phase for materials like cholesteryl benzoate
Cholesteryl benzoate
Cholesteryl benzoate, also called 5-cholesten-3-yl benzoate, is an organic chemical, an ester of cholesterol and benzoic acid. It is a liquid crystal material forming cholesteric liquid crystals with helical structure....
, and noted that such mesophases "involve strong twists around a direction normal to the positive optical axis
Optical axis
An optical axis is a line along which there is some degree of rotational symmetry in an optical system such as a camera lens or microscope.The optical axis is an imaginary line that defines the path along which light propagates through the system...
".
Scientists have followed Friedel’s classification and the term mesophase for the intermediate states has also been adopted from him. He was of the conviction that the term liquid crystal
Liquid crystal
Liquid crystals are a state of matter that have properties between those of a conventional liquid and those of a solid crystal. For instance, an LC may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many different types of LC phases, which can be...
did not bear scrutiny. Indeed, Dunmur and Sluckin (2011) say "The liquid crystals were not crystals at all, but peculiar liquids with some hint of solid properties."
In 1931 Georges published, with his son Edmond Friedel, the results of their X-ray crystallography
X-ray crystallography
X-ray crystallography is a method of determining the arrangement of atoms within a crystal, in which a beam of X-rays strikes a crystal and causes the beam of light to spread into many specific directions. From the angles and intensities of these diffracted beams, a crystallographer can produce a...
studies: "The physical properties of the mesophases in general, and their importance in a scheme of classification."
Important publications
- Groupements cristallins (1904)
- Etudes sur les lois de Bravais (1907)
- Les états mésomorphes de la matiere (1922)
See also
- The Friedel familyFriedel familyFour French scientists with the same Friedel family name are in direct lineage, Charles, Georges, Edmond and Jacques:* Charles Friedel , French chemist known for the Friedel-Crafts reaction...
is a rich lineage of French scientists:- Charles FriedelCharles FriedelCharles Friedel was a French chemist and mineralogist. A native of Strasbourg, France, he was a student of Louis Pasteur at the Sorbonne...
(1832–1899), French chemist known for the Friedel-Crafts reactionFriedel-Crafts reactionThe Friedel–Crafts reactions are a set of reactions developed by Charles Friedel and James Crafts in 1877. There are two main types of Friedel–Crafts reactions: alkylation reactions and acylation reactions. This reaction type is a form of electrophilic aromatic substitution... - Georges Friedel (1865–1933), here above described, French crystallographer and mineralogist; son of Charles
- Edmond Friedel (1895–1972), French Polytechnician and mining engineer, founder of BRGM, the French geological survey; son of Georges
- Jacques FriedelJacques FriedelJacques Friedel FMRS is a French physicist and material scientist.-Life:His great-grand father Charles Friedel was an organic chemist and crystallographer at Paris-Sorbonne University, his grand-father Georges Friedel worked on liquid crystals, and his father Edmond Friedel was the director of the...
, (1921-), French physicist; son of Edmond, see the French site for Jacques Friedel
- Charles Friedel
External links
- François Grandjean (1935) George Friedel, Bulletin de la Société Française de Minéralogie, weblink from Annales des Mines (French).
- Maurice Kleman (2005) Georges Friedel et "Les phases mésomorphes de la matière"., weblink to Institut de Minéralogie et de Physique des Milieux Condensés (French).