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Tytuł:
Błękit Majów , jedno z najważniejszych osiągnięć Mezoameryki
Maya Blue , one of the most important achievements of Mesoamerica
Autorzy:
Łukarska, M.
Zywert, A.
Kowalak, S.
Powiązania:
https://bibliotekanauki.pl/articles/172584.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
Błękit Majów
zeolity
pigmenty
enkapsulacja
indygo
Maya Blue
pigments
zeolites
indigo
encapsualtion
Opis:
The Maya Blue is a famous blue pigment developed by pre-Columbian civilizations of Mesoamerica and manufactured there for about thousand years. It was applied for body decoration, important for cruel religious rituals, as well as for artistic paintings, murals, or coloration of ceramics. Its production was abandoned in XVII century and the procedure forgotten. The chemical nature of this blue pigment remained a puzzle for a long time and only in nineteen sixties it was revealed [1, 2] that it is a composite consisting of inorganic matrix (palygorskite) that accommodates molecules of organic dye – indigo. The preparation procedure was rediscovered [3] and the products analogous to classical Maya Blue could be obtained by simple thermal insertion of indigo into palygorskite (and also into sepiolite). However, the nature of chemical interaction between dye and matrix that provides very high resistibility of resulting pigments remains still not satisfactorily explained. The hydrogen bonds or coordinative interaction with matrix cations are taken into an account. Zeolites and other molecular sieves can be efficiently applied as matrices for pigments similar to Maya Blue. The coloration and other properties of pigments can be considerably changed by initial modification of zeolites with various cations, what supports an important role of complexes formed by dye molecules and zeolite cations. On the other hand, the zeolite-like materials AlPO4 as well as to some extent mesoporous silica (with some contribution of micropores) lacking any cations are also efficient matrices for pigments analogous to Maya Blue. Not only indigo, but also indigo derivatives (leucoindigo, thioindigo, indigo carmine) could be embedded inside the molecular sieves. The thermal insertion as well as crystallization of zeolites from gels supplemented with respective dye can be used for pigment synthesis. It is interesting that role of matrix can be also played by representative of novel MOF family of the molecular sieves.
Źródło:
Wiadomości Chemiczne; 2012, 66, 7-8; 715-739
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Krótka historia niektórych wzorów
A short history of some formulas
Autorzy:
Kroszczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/172754.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
brazylina
chryzyna
hematoksylina
historia chemii
indygo
kwas salicylowy
brazilin
chrysin
haematoxilin
history of chemistry
indigo
salicylic acid
Opis:
This article is an attempt to present how the classical detective work has been performed in order to determine chemical structures. In the past, discussion on these examples was the way of learning of the organic chemistry. Thermal degradation was the main method of analysis currently replaced with the spectroscopy. Perhaps the history of chemistry may help to understand mentalities of creators of new branches of science. On the other hand, it gives arguments for a cultivation of „impractical” sciences. The article describes the earliest attempts to present simple organic formulas undertaken by Couper and Kekulé. Examples of a transformation of aromatic compounds present how results of derivatization led to conclusions concerning structures. Experiments and logic line of thought was supported by a great intuition. More complicated molecules were investigated by degradation reactions. For example, A. Baeyer at the beginning of his investigations concerning indigo, subjected isatin (obtained from indigo by oxidation) to different reducing reagents. He obtained indoldiol, oxindole, indole etc. Then these relatively simple compounds were synthesized and served as by-products for indigo. Some methods of the industrial production of indigo were elaborated on the base of works of Baeyer [16–20]. Similarly, the structures of chrysin, brazilin and haematoxilin have been resolved mainly by their degradation. The final structures were confirmed by synthesis.
Źródło:
Wiadomości Chemiczne; 2013, 67, 7-8; 733-749
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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