{{Use American English|date = April 2019}} {{Short description|Branch of chemistry and physics}} [[File:Milk.jpg|thumb|Milk is an emulsified colloid of liquid butterfat globules of 0.1 to 10 micrometer dispersed within a water-based solution.]]
'''Interface and colloid science''' is an interdisciplinary intersection of branches of chemistry, physics, nanoscience and other fields<ref>{{Cite book |last=Lyklema |first=J. |url=https://books.google.com/books?id=bX4_GQGPzrgC&pg=SA3-PA31 |title=Fundamentals of Interface and Colloid Science: Particulate Colloids |date=2005-03-30 |publisher=Elsevier |isbn=978-0-08-045439-9 |language=en}}</ref> dealing with colloids, heterogeneous multiphase systems that contain extensive interface. One of the examples is colloid solution, which is a heterogeneous mixture in which the particle size of the substance is intermediate between a true solution and a suspension, i.e. between 1–1000 nm. Smoke from a fire is an example of a colloidal system in which tiny particles of solid float in air. Just like true solutions, colloidal particles are small and cannot be seen by the naked eye. They easily pass through filter paper. But colloidal particles are big enough to be blocked by parchment paper or animal membrane. Wetted porous materials, thin oil films on water interface are other examples of systems studied by interfaces and colloid science.
Interface and colloid science has applications and ramifications in the chemical industry, pharmaceuticals, biotechnology, ceramics, minerals, nanotechnology, and microfluidics, among others.
== History == Interface and colloid science remained empirical for a long time. There were some sporadic mathematical models, like electrokinetic theories in 1903 by Marian Smoluchowski,<ref>{{cite journal |first=M. |last=von Smoluchowski |journal=Bull. Int. Acad. Sci. Cracovie |volume=184 |year=1903 |title=Contribution à la théorie de l'endosmose électrique et de quelques phénomènes corrélatifs}}</ref><ref>{{cite book |last1=Dukhin |first1=Andrei S. |last2=Xu |first2=Renliang |title=Zeta Potential: Fundamentals, Methods, and Applications |date=2025 |publisher=Academic Press |location=London Cambridge, MA |isbn=978-0-443-33443-6 |url=https://www.sciencedirect.com/bookseries/interface-science-and-technology/vol/39/suppl/C}}</ref>. or the theory of Brownian motion by Albert Einstein in 1905 <ref name="Einstein-1905">{{cite journal|last=Einstein|first=Albert|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 |language=de |journal=Annalen der Physik |volume=322 |issue=8 |pages=549–560 |doi=10.1002/andp.19053220806 |date=1905 |url=http://www.physik.uni-augsburg.de/annalen/history/einstein-papers/1905_17_549-560.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.physik.uni-augsburg.de/annalen/history/einstein-papers/1905_17_549-560.pdf |archive-date=2022-10-09 |url-status=live |bibcode=1905AnP...322..549E |doi-access=free }}</ref><ref name="Feynman-1964">{{cite book | last = Feynman |first = Richard | year = 1964 | chapter = The Brownian Movement | chapter-url = https://feynmanlectures.caltech.edu/I_41.html | title = The Feynman Lectures of Physics, Volume I | page = 41 }}</ref>. However, these were exceptions stressing more empirical approach to the main problem of this science, including stability of colloids and thin films.
This situation has changed dramatically after invention of DLVO theory in the 1940s by the schools of Boris Derjaguin and Theodoor Overbeek.<ref>{{Citation | first1=B. | last1=Derjaguin | first2=L. | last2=Landau | title=Theory of the stability of strongly charged lyophobic sols and of the adhesion of strongly charged particles in solutions of electrolytes | journal=Acta Physico Chimica URSS | volume=14 | page=633 | year=1941}}</ref><ref name="Verwey">{{Citation | first1=E. J. W. | last1=Verwey | first2=J. Th. G. | last2=Overbeek | title=Theory of the stability of lyophobic colloids | journal=The Journal of Physical and Colloid Chemistry | publisher=Elsevier | location=Amsterdam | year=1948 | volume=51 | issue=3 | pages=631–6 | doi=10.1021/j150453a001 }}</ref> The progress of DVLO theory was described by Pierandrea Lo Nostro and Barry Ninham in 2019 as:<ref name="Ninham">{{Citation | first1=P.L. | last1=Nostro| first2=B.W.| last2=Ninham | title=After DLVO : Hans Lyklema and the keepers of the faith | journal= Advances in Colloid and Interface Science | publisher=Elsevier | location=Amsterdam | year=2020 | volume=276| pages=102082|url= https://www.scopus.com/pages/publications/85076833829}}</ref>
{{Quote2|So in one generation colloid science had moved from a backwater of physical chemistry, puddling around in mud as it were, to center stage in theoretical physics!}}
Further studies by many different groups revealed cracks in the foundations of interface and colloid science. The two main problems were formulated by Ninhan with co-authors in several papers.<ref name="Ninham" /><ref>{{cite journal |first=BW |last=Ninham|title= The Bio logical/Physical Sciences Divide, and the Age of Unreason |journal=Substantia|volume=1(1) |year=2017 |pages=7-24|url= https://researchportalplus.anu.edu.au/en/publications/the-biologicalphysical-sciences-divide-and-the-age-of-unreason/}}</ref> The first one is related to cross talk between macroscopic electrostatic double layer and Van der Waals forces. The second one is associated with the role of dissolved gas, and its self organization which is ignored in modern theories.
==See also== * Interface (matter) * Electrokinetic phenomena * Surface science
==References==
{{reflist|30em}}
== Further reading ==
*Hackley, V.A. and Ferraris, C.F. [https://www.nist.gov/node/656476 "The Use of Nomenclature in Dispersion Science and Technology"], NIST, special publication 960-3 (2001); *Lyklema, J. [https://books.google.com/books?id=bX4_GQGPzrgC&pg=SA3-PA31 “Fundamentals of Interface and Colloid Science”], vol.2, page.3.208, 1995 {{ISBN|0-12-460529-X}} *Russel, W.B., Saville, D.A. and Schowalter, W.R. [https://books.google.com/books?id=FZIh-V1Asn8C “Colloidal Dispersions”], Cambridge University Press, 1992 {{ISBN|0-521-42600-6}} *{{cite book|last=Israelachvili|first=Jacob|title=Intermolecular and Surface Forces, Second Edition: With Applications to Colloidal and Biological Systems|year=2010|publisher=Academic Press|location=London|isbn=978-0-12-375181-2|pages=480}}
==External links== * [https://www.mpikg.mpg.de/profile Max Planck Institute of Colloids and Interfaces] * [https://www.colloidssurfaces.org/ American Chemical Society division of Colloid & Surface Chemistry]
{{Authority control}} {{Branches of chemistry}} Category:Chemical mixtures Category:Colloidal chemistry Category:Condensed matter physics