Accueil du site > 5. Programmes > ANR Nanochéops (2009-2012)
Ce projet pluridisciplinaire vise à comprendre dans quelle mesure la matrice amorphe du cheveu peut être considérée comme un ensemble de nanoréacteurs qui sont d’une part à l’origine des phénomènes de dégradation des œuvres des musées à base de kératine (momies, objets archéologiques et ethnographiques) et, d’autre part, permettent la préparation de nanocristaux de sulfures métalliques, semi-conducteurs et auto organisés. En réalisant différents traitements en milieu alcalin par des sels de plomb, cadmium ou (...)
A l’origine de ce projet, une publication de 2006 dans Nanoletters. Mélanger de la chaux et de l’oxyde de plomb pour en faire une pâte, s’en frotter les cheveux le soir et se peigner le matin. Cette vieille recette pour teindre les cheveux en noir, déjà mentionnée par Galien, le plus célèbre médecin de la Rome antique, a éveillé l’intérêt de Philippe Walter et Éléonore Welcomme, respectivement chercheur et doctorante en chimie au Laboratoire du Centre de recherche et de restauration des musées de France au (...)
The protocol of preparation of keratinized samples (e.g. hair, furs ...) for radiocarbon dating that we have developed is based on the selective extraction of keratin from the bulk part of the shaft (cortex). The aim of this method is to eliminate the cuticle which could contain exogenous carbon from external contaminations. The total treatment takes place as follows : a washing / dry cleaning, a soft treatment with diluted acidic and basic solutions (Acid/Alkali/Acid method) similar to the (...)
A chemical reaction, derived from an ancient recipe for hair dyeing, is used to precipitate nanoparticles of mercury sulphide in hair by the simple process of immersion in a water solution of Ca(OH)2 and HgO. After several days, HgS nanoparticles appear throughout the hair and are particularly numerous in the various interfaces. The formation of these nanoparticles has been studied by analytical and atomic resolution electron microscopy. High resolution quantitative analysis allowed the (...)
A skin sample from a South-Andean mummy dating back from the XIth century was analyzed using time-of-flight secondary ion mass spectrometry imaging using cluster primary ion beams (cluster-TOF-SIMS). For the first time on a mummy, skin dermis and epidermis could be chemically differentiated using mass spectrometry imaging. Differences in amino-acid composition between keratin and collagen, the two major proteins of skin tissue, could indeed be exploited. A surprising lipid composition of (...)
The synthesis and detailed characterization of gold nanoparticles (AuNPs) inside human hair has been achieved by treatment of hair with HAuCl4 in alkaline medium. The AuNPs, which show a strong red fluorescence under blue light, are generated inside the fiber and are arranged in the cortex in a remarkably regular pattern of whorls based on concentric circles, like a fingerprint. It opens an area of genuine nanocomposites with novel properties due to AuNPs inside the hair shaft. Voir le (...)