Search results for "Indigo"
showing 6 items of 36 documents
Maya Blue as a nanostructured polyfunctional hybrid organic–inorganic material: the need to change paradigms
2009
Maya Blue, an ancient nanostructured organic–inorganic hybrid material resulting from the attachment of indigo, a natural dye, to a phyllosilicate clay, palygorskite, has received considerable attention of late. Despite intensive research, several aspects remain unsolved, in particular the nature of the indigo–palygorskite association. Recent results suggest that the Maya Blue pigment is a complex system in which different topological isomers of various indigoid molecules attached to the palygorskite matrix coexist.
ChemInform Abstract: Maya Blue as a Nanostructured Polyfunctional Hybrid Organic-Inorganic Material: The Need to Change Paradigms.
2010
Maya Blue, an ancient nanostructured organic–inorganic hybrid material resulting from the attachment of indigo, a natural dye, to a phyllosilicate clay, palygorskite, has received considerable attention of late. Despite intensive research, several aspects remain unsolved, in particular the nature of the indigo–palygorskite association. Recent results suggest that the Maya Blue pigment is a complex system in which different topological isomers of various indigoid molecules attached to the palygorskite matrix coexist.
On the interpretation of the Raman spectra of Maya Blue: a review on the literature data
2011
The Raman spectroscopy of Maya Blue (MB), a nanostructured organic–inorganic hybrid material, has received considerable attention. A re-evaluation of the Raman literature data for indigo dye, genuine MB samples and model specimens obtained by the binding of indigo to phyllosilicate clays, such as palygorskite and sepiolite, using chemometric analysis of normalised spectra is reported. Available data present features in support of the following ideas: (1) dehydroindigo accompanies indigo in MB; (2) different topological isomers, i.e. dye molecules attached to different coordinative sites of the palygorskite framework, are involved in MB; and (3) different procedures were probably used for pr…
NATURAL INDICO FROM ISATIS TINCTORIA L. FOR THE VALORISATION OF SICILIAN CROPS
2012
Isatis tinctoria L. or woad (Brassicaceae) is an upright herbaceous biennal species up to 120 cm in height. It is in Mediterranean counlries, a common plant cultivated through out centuries to produce the blue dye indigo. With increasing concem for sustainability and a demand from consumers for naturally sourced products, there is a revival of interest in naturai indigo as an agricultural crop produci. Indigo is formed after the extraction of indigo precursors in the leaves of these plants: mainly isatans in woad These compounds are extracted by steeping leaves in warm water. With woad, the addition of alkali to the steep water releases free indoxyl, which forms indigo after a vigorous aera…
Un petit essaye sur les matières premières pour faire la teinture à cuve
2015
Les cultures du l’Orient teintaient in bleu depuis le Néolithique. L'art de la teinture à l’Indigo a prospéré dans la vallée de l'Indus, en Mésopotamie et l'Égypte antique, et la Grèce. Cet artisanat renaît dans la ville d'Alexandrie à l'époque hellénistique. Dans le cas du colorant à la cuve, l'art de préserver une cuve ou sa remontée, pour ne pas perdre la teinture, déboise être un travail spécialisé dans l’Antiquité. La connaissance de ces procédures, en même temps que la présence des restes des bâtiments des ateliers pour la teinture fouillées dans les différents territoires de l’Empire Romain, à l’Orient (Tell Beit Mirsin) et à l’Occident (Pompéi, Rome, Hostie, Barcino), montre la cour…
Multianalytical characterization of pigments from funerary artefacts belongs to the Chupicuaro Culture (Western Mexico): Oldest Maya blue and cinnaba…
2019
Abstract The colours used in Pre-Hispanic Mesoamerica to decorate walls, codices or artefacts have been the subject of numerous studies, with particular attention to Maya blue, red and white pigments. However, most of these studies have been focused on emblematic cultures of the Classic period (ca. 300–1000 CE), such as Teotihuacan and Maya cultures. This work proposes a new chronology of the preparation and use of these pigments, particularly Maya blue, by analysing samples of the Pre-Classic period (ca. 1800 BCE–300 CE). The samples belong to ceremonial artefacts decorated with blue, red and white pigments, in a funerary context from the Chupicuaro culture, which was developed between 600…