laponite
{{Short description|Synchetic chemical compound}}
Laponite is a synthetic smectite clay invented in 1962 by clay scientist Barbara Neumann. Usually produced as powder, laponite is a nanomaterial made up of very small disk-shaped crystals used in multiple industrial applications. Laponite was first marketed by the company Laporte plc and is currently produced by BYK Additives & Instruments.{{cite patent|inventor=Neumann, B.S.|title= Improvements in or Relating to Synthetic Clay-Like Minerals|country=GB|number=1054111|fdate=26 June 1962}}{{cite journal|last=Neumann|first=B.S.|title=Behaviour of a synthetic clay in pigment dispersions|journal=Rheologica Acta|volume=4|pages=250–255|year=1965|issue=4 |doi=10.1007/BF01973660 |bibcode=1965AcRhe...4..250N |url= https://doi.org/10.1007/BF01973660}}{{cite journal|last1=Brunchi|first1=C.-E.|last2=Morariu|first2=S.|year=2024|title=Laponite—From Dispersion to Gel—Structure, Properties, and Applications|journal=Molecules|volume=29|number=2823|page=2823 |doi=10.3390/molecules29122823 |doi-access=free |pmid=38930887 |pmc=11206873 }}{{cite journal|year=2021|title=Dr Barbara S. Neumann: Clay Scientist, Industrial Pioneer, Creator of Laponite|first1=Kirill|last1=Shafran|first2=Christopher V|last2=Jeans|first3=Simon J|last3=Kemp|first4=Kevin|last4=Murphy|journal=Elements|volume=17|issue=1 |pages=69–70|doi=10.2138/gselements.17.1.69 |bibcode=2021Eleme..17...69S |
url=https://doi.org/10.2138/gselements.17.1.69}}{{cite journal|first1=Helena|last1=Tomás|first2=Carla S.|last2=Alves|first3=João|last3=Rodrigues|title=
Laponite®: A key nanoplatform for biomedical applications?|journal=
Nanomedicine: Nanotechnology, Biology and Medicine|volume=14|year=2018|issue=7 |pages=2407–2420|doi=10.1016/j.nano.2017.04.016 |pmid=28552649 |url=
https://doi.org/10.1016/j.nano.2017.04.016}} Laponite is not an approved mineral species, since it is not naturally occurring and it is not produced by geological processes.{{cite web|url=https://www.mindat.org/min-12338.html|title=Laponite|work=mindat.org}}
In the first formulation of laponite created by Neumann in 1962, the synthetic clay was determined to be a fluorohectorite and was produced in the form of discs 1 nanometer thick and with a diameter of 60 to 80 nanometers. This went into mass production in 1964.{{cite journal|year=2020|title=Dr Barbara S. Neumann: Clay Scientist and Industrial Pioneer|first1=Kirill|last1=Shafran|first2=Christopher V|last2=Jeans|first3=Simon J|last3=Kemp|first4=Kevin|last4=Murphy|journal= Clay Minerals |volume=55|pages=256–260|doi=10.1180/clm.2020.35 |url=https://doi.org/10.1180/clm.2020.35}} The mineral structure of the clay gives laponite its particular physical characteristics and is similar to the smectite group of clay minerals, with a 2:1 layered crystal structure in which two tetrahedral silica sheets lie either side of an octahedral sheet containing magnesium ions. In 1966, Neumann patented a second formulation of laponite, called 'Laponite RD'. This form was free from fluorine, and has subsequently become the most widely used form of laponite.{{cite patent|inventor=Neumann, B.S.|title=Clays|country=GB|number=1213122|fdate=12 September 1966}} This form of laponite has an empirical formula of {{chem2|Na0.7[(Si8Mg5.5Li0.3)O20(OH)4]}}. In later years, Neumann also created other variants of laponite including a lithium-free magnesium silicate clay, a form of synthetic stevensite, and an iron silicate clay, which was a synthetic form of nontronite.