Laponite

Laponite is a synthetic smectite clay that was invented in 1962 by clay scientist Barbara Neumann. Laponite is usually produced as powder. It is a nanomaterial, made up of very small disk-shaped crystals, that is used in multiple industrial applications. Laponite was first marketed by the company Laporte plc, and is currently produced by BYK Additives & Instruments.[1][2][3][4][5] Laponite is not an approved mineral species, since it is not naturally occurring and it is not produced by geological processes.[6]

## Development of laponite

[edit]

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 that were 1 nanometer thick, and with a diameter of 60 to 80 nanometres. This went into mass production in 1964.[7] The mineral structure of the clay gives laponite its particular physical characteristics. It has a structure 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.[5]

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.[8] This form of laponite has an empirical formula of Na0.7[(Si8Mg5.5Li0.3)O20(OH)4].[5]

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.[7]

## References

[edit]

1. ^ GB 1054111, Neumann, B.S., "Improvements in or Relating to Synthetic Clay-Like Minerals"
2. ^ Neumann, B.S. (1965). "Behaviour of a synthetic clay in pigment dispersions". Rheologica Acta. 4 (4): 250–255\. Bibcode:1965AcRhe...4..250N. doi:10.1007/BF01973660.250-255&rft.date=1965&rft_id=info:doi/10.1007/BF01973660&rft_id=info:bibcode/1965AcRhe...4..250N&rft.aulast=Neumann&rft.aufirst=B.S.&rft_id=https://doi.org/10.1007/BF01973660&rfr_id=info:sid/en.wikipedia.org:Laponite" class="Z3988">
3. ^ Brunchi, C.-E.; Morariu, S. (2024). "Laponite—From Dispersion to Gel—Structure, Properties, and Applications". Molecules. 29 (2823): 2823. doi:10.3390/molecules29122823. PMC 11206873. PMID 38930887.
4. ^ Shafran, Kirill; Jeans, Christopher V; Kemp, Simon J; Murphy, Kevin (2021). "Dr Barbara S. Neumann: Clay Scientist, Industrial Pioneer, Creator of Laponite". Elements. 17 (1): 69–70\. Bibcode:2021Eleme..17...69S. doi:10.2138/gselements.17.1.69.69-70&rft.date=2021&rft_id=info:doi/10.2138/gselements.17.1.69&rft_id=info:bibcode/2021Eleme..17...69S&rft.aulast=Shafran&rft.aufirst=Kirill&rft.au=Jeans,+Christopher+V&rft.au=Kemp,+Simon+J&rft.au=Murphy,+Kevin&rft_id=https://doi.org/10.2138/gselements.17.1.69&rfr_id=info:sid/en.wikipedia.org:Laponite" class="Z3988">
5. ^ a b c Tomás, Helena; Alves, Carla S.; Rodrigues, João (2018). "Laponite®: A key nanoplatform for biomedical applications?". Nanomedicine: Nanotechnology, Biology and Medicine. 14 (7): 2407–2420\. doi:10.1016/j.nano.2017.04.016. PMID 28552649.2407-2420&rft.date=2018&rft_id=info:doi/10.1016/j.nano.2017.04.016&rft_id=info:pmid/28552649&rft.aulast=Tomás&rft.aufirst=Helena&rft.au=Alves,+Carla+S.&rft.au=Rodrigues,+João&rft_id=https://doi.org/10.1016/j.nano.2017.04.016&rfr_id=info:sid/en.wikipedia.org:Laponite" class="Z3988">
6. ^ "Laponite". mindat.org.
7. ^ a b Shafran, Kirill; Jeans, Christopher V; Kemp, Simon J; Murphy, Kevin (2020). "Dr Barbara S. Neumann: Clay Scientist and Industrial Pioneer". Clay Minerals. 55: 256–260\. doi:10.1180/clm.2020.35.256-260&rft.date=2020&rft_id=info:doi/10.1180/clm.2020.35&rft.aulast=Shafran&rft.aufirst=Kirill&rft.au=Jeans,+Christopher+V&rft.au=Kemp,+Simon+J&rft.au=Murphy,+Kevin&rft_id=https://doi.org/10.1180/clm.2020.35&rfr_id=info:sid/en.wikipedia.org:Laponite" class="Z3988">
8. ^ GB 1213122, Neumann, B.S., "Clays"