Chrome orange
Chrome orangeis amixed oxidewith thechemical formulaPb2CrO5.It can be made by treating a lead(II) salt with an alkaline solution of achromateor by treatingchrome yellow(PbCrO4) with strongly basic solution.[2]
Synthesis and nanoparticles
[edit]Pb2CrO5can be synthesized with agas-liquid precipitationprocess.[3]Changing the pH controls whether PbCrO4or Pb2CrO5is created.[3]
Orthorhombicnanocrystals can be selectively synthesized in a facile room temperature solution for Pb2CrO5.[4]
Using amicrowave-assisted ionic liquid(MAIL) method, bundle and rod-like nanocrystals of Pb2CrO5were formed.[5]The bundles look like bundles of straw, secured in the middle.[5]In basic solution, single-crystalline Pb2CrO5could be formed by heating lead acetate and potassium dichromate with microwave radiation for only 10 minutes at 90 celsius.[5]The MAIL process is simple, fast, and does not employ surfactants.[5]The presence of hydroxide changes the phase that is formed. Using NaOH,monoclinicPb2CrO5is formed.[5]The bundle and rod-shaped structures are sensitive to electron beam irradiation, which will turn them into many small particles.[5]
Properties
[edit]TheGibbs free energyof Pb2CrO5was determined in 2010 and is given as
ΔfG°mPb2CrO5(s)±0.30/(kJ•mol−1)=-1161.3 +0.4059(T/K) (859≤T/K≤1021).[6]
Visible lightactivity up to 550 nanometers has been recorded for Pb2CrO5.[7]
Pigment synthesis
[edit]In an catalog published c. 1835, Winsor and Newton paint company identify ten synthetic pathways for producing chrome orange, also called deep yellow.[8]Chrome orange is made ofPbCrO4mixed with basic lead chromate (Pb2CrO5).[8]It has been described as a “yellowish red or sometimes a beautiful deep red” in alkaline conditions.[8]A deep yellow can be created using PbCrO4and lead sulfate.[8]There are ten synthetic methods for preparing deep chrome yellow (that made with Pb2CrO5), which require a chromate source, a basic lead source, additives, and a sulfate source.[8]CrO42-+ H2SO4+Pb(Ac)2• 2Pb(OH)2→ PbCrO4+Pb2CrO5at apHof approximately seven is the synthesis.[8]
Controlling the pH was Winsor and Newton’s method for creating pigments from the pale yellow to the deep chrome orange.[8]The resulting product has a high stability to light, which is always coveted by artists and collectors.[8]
History
[edit]The natural mineral crocoite was discovered in 1797 byLouis Vauquelinand chrome orange was synthesized as a pigment for the first time in 1809.[9]Pb2CrO5is found in mineral form asphoenicochroite,which is amonoclinic,red, translucent mineral found in various places across the world, including Russia, the USA, and Chile.[10]
Use as a pigment
[edit]| Chrome Orange | |
|---|---|
 Color coordinates | |
| Hex triplet | #E73501 |
| sRGBB(r,g,b) | (231, 53, 1) |
| HSV(h,s,v) | (14°, 100%, 91%) |
| CIELChuv(L,C,h) | (51, 147, 16°) |
| Source | ColourLex[11] |
| B:Normalized to [0–255] (byte) | |
Chrome orange can range in color from light to deep orange and is no longer in production as a pigment.[9]It has also been known as Derby red, Persian red, and Victoria red.[9]It was first recorded as a pigment in 1809 and was perfect for some impressionist painters in the nineteenth century. The yellow-orange pigment of the boat inRenoir’s 1879 painting, The Seine at Asnières (The Skiff) at theNational Gallery, London.[9]Chrome orange was used extensively inFrederic Leighton'sFlaming June(1895;Museo de Arte de Ponce).[1]
See also
[edit]References
[edit]- ^abColor in the Making.London, UK: Black Dog Publishing. 2013. p. 104.ISBN9781907317958.
- ^Völz, Hans G.; et al. (2006). "Pigments, Inorganic".Ullmann's Encyclopedia of Industrial Chemistry.Weinheimdoi=10.1002/14356007.a20_243.pub2: Wiley-VCH.doi:10.1002/14356007.a20_243.pub2.ISBN3527306730.
{{cite encyclopedia}}:CS1 maint: location (link). - ^abGu, LiNa; Meng, GuangYao (2007-09-05)."Synthesis and characterization of two PbO-chromium oxides".Powder Technology.178(1): 1–4.doi:10.1016/j.powtec.2007.01.017.ISSN0032-5910.
- ^Ma, Ming-Guo; Zhu, Ying-Jie; Li, Shu-Hong (2009-02-04)."A simple route to the synthesis of BaCrO4 microstructures at room temperature".Materials Research Bulletin.44(2): 288–293.doi:10.1016/j.materresbull.2008.06.003.ISSN0025-5408.
- ^abcdefWang, Wei-Wei; Zhu, Ying-Jie (2005-03-01)."Synthesis of PbCrO 4 and Pb 2 CrO 5 Rods via a Microwave-Assisted Ionic Liquid Method".Crystal Growth & Design.5(2): 505–507.doi:10.1021/cg0497546.ISSN1528-7483.
- ^Sahu, Sulata Kumari; Ganesan, Rajesh; Gnanasekaran, T. (2010-01-01)."Standard molar Gibbs free energy of formation of Pb5CrO8(s), Pb2CrO5(s), and PbCrO4(s)".The Journal of Chemical Thermodynamics.42(1): 1–7.doi:10.1016/j.jct.2009.06.026.ISSN0021-9614.S2CID55549520.
- ^Lee, Heung Chan; Cho, Sung Ki; Park, Hyun S.; Nam, Ki Min; Bard, Allen J. (2017-08-24)."Visible Light Photoelectrochemical Properties of PbCrO 4, Pb 2 CrO 5, and Pb 5 CrO 8".The Journal of Physical Chemistry C.121(33): 17561–17568.doi:10.1021/acs.jpcc.7b03230.ISSN1932-7447.
- ^abcdefghOtero, Vanessa; Pinto, Joana V.; Carlyle, Leslie; Vilarigues, Márcia; Cotte, Marine; João Melo, Maria (2017). "Nineteenth Century Chrome Yellow and Chrome Deep from Winsor & Newton".Studies in Conservation.62(3): 123–149.doi:10.1080/00393630.2015.1131478.S2CID138176187– via EBSCO Host.
- ^abcd"Pigments through the Ages - Overview - Chrome orange".webexhibits.org.Retrieved2022-05-11.
- ^"Phoenicochroite".mindat.org.Retrieved2022-05-11.
- ^"Chrome orange - ColourLex".ColourLex.Retrieved22 December2022.
Further reading
[edit]- Kühn, H. and Curran, M., Chrome Yellow and Other Chromate Pigments, in Artists’ Pigments. A Handbook of Their History and Characteristics, Vol. 1, L. Feller, Ed., Cambridge University Press, London 1986, p. 208 – 211.
- Chrome Orangeat ColourLex