Papers by Bertrand Lavedrine
The journal of photographic science, 1995
AbstractThe degradation mechanisms of cellulose nitrate were investigated using mass spectrometry... more AbstractThe degradation mechanisms of cellulose nitrate were investigated using mass spectrometry and size exclusion chromatography. After extraction with dichloromethane and analysis by coupling gas chromatography and mass spectrometry, two plasticizers were found: camphor and triphenylphosphate. A reaction product between nitrogen dioxide and triphenylphosphate was observed. The most important results contain the analysis of degraded and undegraded cellulose nitrate bases, by size exclusion chromatography and Fourier transform infra-red spectroscopy: cleavage of the polymer chain is seen to be the first step of the degradation.
En 1903, louis lumiere depose un brevet sur un de photographie en couleurs qui sera connu plus ta... more En 1903, louis lumiere depose un brevet sur un de photographie en couleurs qui sera connu plus tard sous le nom d'autochrome. A elle seule, la collection du banquier albert kahn (boulogne) recele plus de 70000 plaques datant de l'entredeux-guerres, avec des vues de la france, de l'indochine, de l'irlande, du japon. . . Ces images sont les rares temoignages des couleurs d'une epoque mais pour combien de temps encore? leurs coloris harmonieux nous conduisent a surestimer leur capacite a resister a l'epreuve du temps. Il n'existe aucune reference qui permette d'etablir que les plaques n'ont pas deja subi des modifications. Nous avons entrepris une recherche dont le but est d'etudier le comportement a long terme des autochromes et de leurs constituants. Pour cela, il etait d'abord necessaire de "percer le mystere de la plaque" en analysant des autochromes et en se confrontant a la fabrication. Ensuite, a partir de tests de vieillissements acceleres sur des constituants isoles, colorants, vernisn, ou sur ces plaques reconstituees et des plaques anciennes, il a ete possible de prevoir leur evolution dans le temps.
HAL (Le Centre pour la Communication Scientifique Directe), Dec 17, 2019
HAL (Le Centre pour la Communication Scientifique Directe), 2022
HAL (Le Centre pour la Communication Scientifique Directe), Oct 23, 2014
HAL (Le Centre pour la Communication Scientifique Directe), Dec 9, 2017
HAL (Le Centre pour la Communication Scientifique Directe), Jun 20, 2011
Journal of Cultural Heritage, May 1, 2022
HAL (Le Centre pour la Communication Scientifique Directe), Mar 7, 2012
Time/Aging Ideal material strongly absorbs below 400 nm Comparison between the IPN and a Commerci... more Time/Aging Ideal material strongly absorbs below 400 nm Comparison between the IPN and a Commercial Glass : Transparency almost identical
Bulletin of The Society of Scientific Photography of Japan, 2014
HAL (Le Centre pour la Communication Scientifique Directe), Mar 21, 2014
HAL (Le Centre pour la Communication Scientifique Directe), Jan 24, 2018
HAL (Le Centre pour la Communication Scientifique Directe), Oct 23, 2013
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
HAL (Le Centre pour la Communication Scientifique Directe), Jul 1, 2014
Gazette des archives, 1998
La conservation, la restauration et l'exposition des images fixes ne peuvent s'envisager ... more La conservation, la restauration et l'exposition des images fixes ne peuvent s'envisager qu'apres avoir etudie de facon poussee la nature des support, le liant et le materiau qui forme l'image. A l'aide de tableaux, l'auteur rappelle les conseils fondamentaux et les normes qui permettent de prolonger la stabilite des images lors de leur stockage ou de leur exploitation.
HAL (Le Centre pour la Communication Scientifique Directe), Nov 22, 2022
The need to gather documentation to assist in the conservation of the Bagan monuments following a... more The need to gather documentation to assist in the conservation of the Bagan monuments following an earthquake in 2016 brought to light a collection of glass plate negatives held in the archive of the Department of Archaeology in Yangon, Myanmar. The collection contains over 5,500 negatives dating from ca. 1901-55. Many images depict the temples within the Bagan archaeological area in great detail, making the collection an important resource for the ongoing restoration of the monuments whilst preserving their authenticity. However, this collection has been stored without specific care in a hot and humid environment and the negatives exhibit degradation. There was an urgent need to improve these conditions to ensure longterm preservation and provide further access and use. This paper explains how the significance of the collection was understood and led to the initiative for its preservation, and how its condition was assessed and helped to inform the preservation decisions within a sustainable approach. The project was carried out within the framework of international collaboration between the UNESCO offices in Thailand and Myanmar,
HAL (Le Centre pour la Communication Scientifique Directe), 1991
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.
Materials today communications, Dec 1, 2019
Polymethyl methacrylate (PMMA) is commonly used as organic glass for the protection of works in m... more Polymethyl methacrylate (PMMA) is commonly used as organic glass for the protection of works in museums. However, their extreme sensitivity to scratching causes problems during maintenance procedures. In order to improve the resistance to abrasion, PMMA has been cross-linked with silica nanoparticles previously modified with 3-(methacryloxy)propyl-trimethoxysilane (MPTS). This functionalization allows both a homogeneous dispersion of the silica nanoparticles in MMA monomer and the PMMA crosslinking which has been confirmed by solid/liquid extraction and DMA analysis. The small nanoparticles (7-10 nm diameter) added in different amounts, are homogeneously dispersed in the transparent (T% > 80%) hybrid PMMAx-SiO2 networks as verified by TGA and TEM microscopy. These hybrid PMMAx-SiO2
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Papers by Bertrand Lavedrine