9 research outputs found
Diffusion Of Indigo Molecules Inside The Palygorskite Clay Channels
The search for durable dyes led several past civilizations to develop
artificial pigments. Maya Blue (MB), manufactured in pre-Columbian Mesoamerica,
is one of the best known examples of an organic-inorganic hybrid material. Its
durability is due to the unique association of indigo molecule and
palygorskite, a particular fibrous clay occurring in Yucatan. Despite 50 years
of sustained interest, the microscopic structure of MB and its relation to the
durability remain open questions. Combining new thermogravimetric and
synchrotron X-ray diffraction analyses, we show that indigo molecules can
diffuse into the channel of the palygorskite during the heating process,
replacing zeolitic water and stabilizing the room temperature phases of the
clay
Association of indigo with zeolites for improved colour stabilization
International audienceThe durability of an organic colour and its resistance against external chemical agents and exposure to light can be significantly enhanced by hybridizing the natural dye with a mineral. In search for stable natural pigments, the present work focuses on the association of indigo blue with several zeolitic matrices (LTA zeolite, mordenite, MFI zeolite). The manufacturing of the hybrid pigment is tested under varying oxidising conditions, using Raman and UV-visible spectrometric techniques. Blending indigo with MFI is shown to yield the most stable composite in all of our artificial indigo pigments. In absence of defects and substituted cations such as aluminum in the framework of the MFI zeolite matrix, we show that matching the pore size with the dimensions of the guest indigo molecule is the key factor. The evidence for the high colour stability of indigo@MFI opens a new path for modeling the stability of indigo in various alumino-silicate substrates such as in the historical Maya Blue pigment
Revisiting Maya Blue and Designing Hybrid Pigments by Archaeomimetism
Maya Blue is actually one of the best known examples of an organic-inorganic
hybrid material. Yet despite 50 years of sustained interest, its microscopic
structure and its relation to durability remain open questions. We address the
issue by archaeomimetism: engineering an archaeoinspired pigment,
satisfactorily reproducing the colour and chemical stability of Maya Blue. By
comparing and contrasting ancient pigment and the new analogue, we deduce a new
explanation for this durability
Un nouveau cachet à collyres découvert à Lyon en mars 2015
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Unprecedented perspectives in the application of CinNapht fluorophores provided by a âLate-stageâ functionalization strategy
International audienceA simple and easyâtoâimplement process based on a nucleophilic aromatic substitution reaction with a wide variety of nucleophiles on a fluorinated CinâNapht is described. This process has the key advantage of introducing multiple functionalities at the very late stage, thus providing access to new applications including photostable and bioconjugatabable large Stokes Shift red emitting dyes, selective organelle imaging agents, or AIEEâbased washâfree lipid droplets imaging in live cells with high signalâtoânoise ratio. The synthesis of benchâstable CinNaphtâF has been optimized and can be reproduced in lagre scale, making it an easyâtoâstore starting material that can be used at will to prepare new molecular imaging tools
Late-stage functionalization of a fluorescent scaffold to afford a new generation of large Stokes shift red-emitting dyes with promising properties for biological imaging
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Late-stage functionalization of a fluorescent scaffold to afford a new generation of large Stokes shift red-emitting dyes with promising properties for biological imaging
International audienc