Editing Soft matter (section)

== History ==
The current understanding of soft matter grew from [[Albert Einstein|Albert Einstein's]] work on [[Brownian motion]],<ref>{{Cite journal |last=Einstein |first=Albert |date=1905 |title=Über die von der molekularkinetischen Theorie der Wärme geforderte Bewegung von in ruhenden Flüssigkeiten suspendierten Teilchen |trans-title=On the Movement of Small Particles Suspended in Stationary Liquids Required by the Molecular-Kinetic Theory of Heat |journal=Annalen der Physik |language=German |volume=322 |issue=8 |pages=549–560 |doi=10.1002/andp.19053220806|bibcode=1905AnP...322..549E |doi-access=free }}</ref><ref>{{Cite journal |last=Mezzenga |first=Raffaele |date=2021-12-22 |title=Grand Challenges in Soft Matter |journal=Frontiers in Soft Matter |volume=1 |pages=811842 |doi=10.3389/frsfm.2021.811842 |issn=2813-0499|doi-access=free }}</ref> understanding that a particle [[Suspension (chemistry)|suspended]] in a [[fluid]] must have a similar thermal energy to the fluid itself (of order of ''[[kT (energy)|kT]]''). This work built on established research into systems that would now be considered colloids.<ref>{{Cite book |last=McLeish |first=Tom |url=https://www.worldcat.org/oclc/1202271044 |title=Soft Matter: a Very Short Introduction |date=2020 |publisher=Oxford University Press |isbn=978-0-19-880713-1 |edition=1st |location=Oxford, United Kingdom |oclc=1202271044}}</ref>

The crystalline optical properties of liquid crystals and their ability to flow were first described by [[Friedrich Reinitzer]] in 1888,<ref>{{Cite journal |last=Reinitzer |first=Friedrich |date=1888 |title=Beiträge zur Kenntniss des Cholesterins |url=http://link.springer.com/10.1007/BF01516710 |journal=Monatshefte für Chemie - Chemical Monthly |language=de |volume=9 |issue=1 |pages=421–441 |doi=10.1007/BF01516710 |s2cid=97166902 |issn=0026-9247}}</ref> and further characterized by [[Otto Lehmann (physicist)|Otto Lehmann]] in 1889.<ref>{{Cite journal |last=Lehmann |first=O. |date=1889-07-01 |title=Über fliessende Krystalle |url=https://www.degruyter.com/document/doi/10.1515/zpch-1889-0434/html |journal=Zeitschrift für Physikalische Chemie |language=en |volume=4U |issue=1 |pages=462–472 |doi=10.1515/zpch-1889-0434 |s2cid=92908969 |issn=2196-7156}}</ref> The experimental setup that Lehmann used to investigate the two melting points of cholesteryl benzoate are still used in the research of liquid crystals as of about 2019.<ref name=":14">{{Cite book |last=DiLisi |first=Gregory A |url=https://iopscience.iop.org/book/978-1-64327-684-7 |title=An Introduction to Liquid Crystals |date=2019 |publisher=IOP Publishing |isbn=978-1-64327-684-7 |doi=10.1088/2053-2571/ab2a6fch1|s2cid=239330818 }}</ref>

In 1920, [[Hermann Staudinger]], recipient of the 1953 [[Nobel Prize in Chemistry]],<ref>Hermann Staudinger – Biographical. NobelPrize.org. Nobel Prize Outreach AB 2023. Mon. 13 Feb 2023. https://www.nobelprize.org/prizes/chemistry/1953/staudinger/biographical/ </ref> was the first person to suggest that polymers are formed through [[Covalent bond|covalent bonds]] that link smaller molecules together.<ref>{{Cite journal |last=Staudinger |first=H. |date=1920-06-12 |title=Über Polymerisation |url=https://onlinelibrary.wiley.com/doi/10.1002/cber.19200530627 |journal=Berichte der Deutschen Chemischen Gesellschaft (A and B Series) |language=en |volume=53 |issue=6 |pages=1073–1085 |doi=10.1002/cber.19200530627 |issn=0365-9488}}</ref> The idea of a [[macromolecule]] was unheard of at the time, with the scientific consensus being that the recorded high molecular weights of compounds like natural rubber were instead due to [[particle aggregation]].<ref>American Chemical Society International Historic Chemical Landmarks. Foundations of Polymer Science: Hermann Staudinger and Macromolecules. http://www.acs.org/content/acs/en/education/whatischemistry/landmarks/staudingerpolymerscience.html  (accessed Feb 13th, 2023).</ref>

The use of [[hydrogel]] in the biomedical field was pioneered in 1960 by [[Drahoslav Lím]] and [[Otto Wichterle]].<ref>{{Cite book |url=https://www.worldcat.org/oclc/1050163199 |title=Hydrogels : recent advances |date=2018 |others=Vijay Kumar Thakur, Manju Kumari Thakur |isbn=978-981-10-6077-9 |location=Singapore |oclc=1050163199}}</ref> Together, they postulated that the chemical stability, ease of deformation, and permeability of certain polymer networks in aqueous environments would have a significant impact on medicine, and were the inventors of the soft [[contact lens]].<ref>{{Cite journal |last1=Wichterle |first1=O. |last2=Lím |first2=D. |date=1960 |title=Hydrophilic Gels for Biological Use |url=https://www.nature.com/articles/185117a0 |journal=Nature |language=en |volume=185 |issue=4706 |pages=117–118 |doi=10.1038/185117a0 |bibcode=1960Natur.185..117W |s2cid=4211987 |issn=0028-0836}}</ref>

These seemingly separate fields were dramatically influenced and brought together by [[Pierre-Gilles de Gennes]]. The work of de Gennes across different forms of soft matter was key to understanding its [[Universality (dynamical systems)|universality]], where material properties are not based on the [[chemistry]] of the underlying [[structure]], more so on the [[Mesoscopic physics|mesoscopic]] structures the underlying chemistry creates.<ref name=":1" /> He extended the understanding of [[Phase transition|phase changes]] in liquid crystals, introduced the idea of [[reptation]] regarding the [[Relaxation (physics)|relaxation]] of polymer systems, and successfully mapped polymer behavior to that of the [[Ising model]].<ref name=":1">{{Cite journal |last1=Joanny |first1=Jean-François |last2=Cates |first2=Michael |date=2019 |title=Pierre-Gilles de Gennes. 24 October 1932—18 May 2007 |journal=Biographical Memoirs of Fellows of the Royal Society |language=en |volume=66 |pages=143–158 |doi=10.1098/rsbm.2018.0033 |s2cid=127231807 |issn=0080-4606|doi-access=free }}</ref><ref>{{Cite journal |last=de Gennes |first=P.G. |date=1972 |title=Exponents for the excluded volume problem as derived by the Wilson method |url=https://linkinghub.elsevier.com/retrieve/pii/0375960172901491 |journal=Physics Letters A |language=en |volume=38 |issue=5 |pages=339–340 |doi=10.1016/0375-9601(72)90149-1|bibcode=1972PhLA...38..339D }}</ref>