Science and Technologyfor the Conservation of Cultural Heritage.

CHARACTERIZATION OF

HISTORICAL BINDERS AND PIGMENTS

BY LASER INDUCED FLUORESCENCE LIF

by

Martina ROMANI

Know To Keep.

Raffaello Sanzio.

Caves of Lascaux

Basilica superiore, Assisi.

Andy Warhol..

Needs.• Need to know to keep.

• Need for non-destructive surveys for the knowledge of materials.

• Need to characterize the material as a pictorial problem of considerable interest.

• Need to identify the presence of consolidant phenomena of biodegradation, and protective.

• Need to create a reference database for historical binders and pigments.

Response.

The laser-induced fluorescence in the UV, as a response to highlight:

•Phenomena of biodegradation.

•Consolidating.

•Main constituents binders and pigments.

Working with laser beams at high brightness, monochromatic and directional, (with a distance from the target (> 20 m)), it is possible the development of remote diagnostics spectroscopic with restitution of images (2D) and models (3D) high resolution (<0.5 mm).

Fluorescence.

•The material absorbs energy in the form of radiation.

•Emission with a frequency lower than the initial one.

•spectroscopy of fluorescence spectroscopic technique whose main applications are in the range spectral UV-VIS.

•Measurement of the radiation emitted after excitation.

•Study of the absorption and emission spectra, which depending on the structure of the material.

Laser Tool (LIF), ENEA Frascati.

How does it works? •Laser hits the surface.

•UV beam, excites pigment / binder that emits light VIS.

•The emission collection is analyzed by a detector.

•Achievement: Fluorescence Spectrum

UV Laser

Materials and Methods Preparation of Samples.

The materials used in this research are pigments and binders.

The pigments are colored substances that are applied on a surface by means of a medium in which they are insoluble, or dispersed in a mass.

The binders or mediums are organic substances, protein-based or lipid delegated the function to bind, and adhere the pigment to the surface.

Stages of the preparation of the mixturespigment binder. After grinding thepowder we proceed to mixing with thebinder and the next draft.

Preparation Of Samples.

The binders prepared according to ancient recipes: Cennino Cennini and Dry Suardo.

Following lying either singly or mixed with pigments, of three types of support; glass, aluminum and cardboard black.

For the analysis of the pigments, in the absence of the classical binders, use has been made to the achievement of the tablets in KBr.

Pigments and Binders on Alluminium and Black Cardboard.

Pigments and Binders on Glass.

Mesures of samples laser to the laser (LIF).

Order d 'Analysis of Samples:

1) Analysis of samples of binders

2) Analysis of samples from the pigment-binder mixtures

3) Analysis of pigments in KBr tablets.

All prepared samples were analyzed at the wavelengths of 266 nm and 355 nm.

Completed the measures the study began decoding of the spectra, and the work of creating the database.

Binder on cardboard. λ : 266 nm. λ : 355 nm.

Red Yolk.

Technique of Tempera paints.

Leonardo Da Vinci; 1494-1498

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Binder’s Database.

Mixture Inorganic Pigment-Binder.

λ : 266 nm. λ : 355 nm.

Yellow oxide dispersed in Linseed Oil.

Oil Painting.

Anonymous Fiorentino.

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Pigment’s Database.

Lacquer madder dispersed in linseed oil.

Oil on board.

Jan Vermeer, 1651.

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The Case of Indigo; Organic or Inorganic?

Conclusions.

• Responses to the needs of the Conservation Scientist.

• LIF analysis for current information on the conservation status.

• Identification of biological attacks and details of the methods of restoration of cultural heritage under study.

• Database as a tool for collecting, exchanging and comparing.

Future Perspectives.

Enrichment of Database by:

• Additional measures of Organic Pigments.

• Exchanges and comparisons with related databases.

• Inclusion of measures of standard samples subjected to accelerated aging and degradation in a climatic chamber.

Martina Romani.martiromani1989@gmail.com

Grazie a tutti per l’attenzione.