Uncovering lead formate crystallization in oil-based paintings
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388980%3A_____%2F20%3A00524413" target="_blank" >RIV/61388980:_____/20:00524413 - isvavai.cz</a>
Alternative codes found
RIV/61389013:_____/20:00524413 RIV/60461446:_____/20:N0000046
Result on the web
<a href="https://doi.org/10.1039/D0DT00327A" target="_blank" >https://doi.org/10.1039/D0DT00327A</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1039/d0dt00327a" target="_blank" >10.1039/d0dt00327a</a>
Alternative languages
Result language
angličtina
Original language name
Uncovering lead formate crystallization in oil-based paintings
Original language description
Lead carboxylates are an extensive group of compounds studied for their promising industrial applications and for their risky behavior when they are formed in oil paintings as corrosion products of lead-based pigments, leading to serious deterioration of paintings. Although the processes leading to the formation of aggregates, protrusions or inclusions, affecting undesirably the appearance of paintings, are assumed to be long term, neo-formed lead carboxylates are detectable in the early stage of paint drying. To uncover the chemical changes in lead pigments during the drying of oil paint films, model systems consisting of minium (Pb3O4) and four common drying oils were studied by X-ray powder diffraction (XRPD), C-13 and Pb-207 solid state NMR (ssNMR) spectroscopy and Fourier-transformed infrared spectroscopy (FTIR). For the first time, a degradation mechanism of Pb(3)O(4)via the crystallization of lead formate (Pb(HCOO)(2)), at the end of oxidative polymerization of oil paint films, was uncovered. The formation of formic acid in oils was proved by gas chromatography-mass spectrometry (GC-MS). Vapor experiments evidenced the susceptibility of Pb3O4 to react with volatile formic acid released during the autoxidation of oils comparably to the direct pigment-binder interactions in paint films. The investigation of the local environment of lead atoms in the paint film by Pb-207 WURST-CPMG NMR spectroscopy showed that Pb(ii) atoms reacted with linseed oil preferentially to form highly crystalline Pb(HCOO)(2), while the local chemical environment of Pb(iv) atoms did not change. The results proved the co-existence of (i) highly crystalline Pb(HCOO)(2), (ii) a highly mobile amorphous phase corresponding to free carboxylic acids or a nascent lead soap phase and (iii) the remaining Pb3O4 in the polymeric/ionomeric network. Pb(HCOO)(2) is assumed to be an intermediate for the conversion of Pb3O4 to lead soaps and/or lead carbonates.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10402 - Inorganic and nuclear chemistry
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2020
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Dalton Transactions
ISSN
1477-9226
e-ISSN
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Volume of the periodical
49
Issue of the periodical within the volume
16
Country of publishing house
GB - UNITED KINGDOM
Number of pages
12
Pages from-to
5044-5054
UT code for WoS article
000530357500009
EID of the result in the Scopus database
2-s2.0-85084167965