In the past, restoration of paintings and other old artwork often involved application of acrylic resins to consolidate and protect them. One of the most important tasks for modern restorers is thus to remove these layers, because it turns out that acrylic resins not only drastically change the optics of the treated artwork, but in many cases they accelerate their degradation.
Italian researchers working with Piero Baglioni at the University of Florence have now developed a technique to effectively remove such old polymer layers from sensitive historic artworks. As the researchers report in the journal Angewandte Chemie, the new cleaning system involves only a tiny proportion of volatile organic compounds. “We have demonstrated the first successful application of a water-based system for the removal of an organic layer from artwork,” says Baglioni. “In addition, our method is simpler and less invasive than traditional processes.”
The scientists use an oil-in-water microemulsion with the organic solvent para-xylene as the oil component. An emulsion is a fine dispersion of droplets of one liquid in another liquid with which the first is not miscible. One example from our daily lives is milk. A microemulsion is an emulsion that forms spontaneously and is stable. It contains substances that act as emulsifiers. Because the individual drops are only nanometer-sized, the mircoemulsion is not milky and opaque, but clear and transparent.
The Italian researchers embedded their micoremulsion in a matrix of a modified type of cellulose—a material used as a thickener for emulsion paints. The matrix makes the cleaning agent viscous, so that it cannot enter very far into the pores of a painting. Its activity is limited to the outer layer, whilst deeper layers of paint do not come into contact with the xylene. The environment is protected as well, because of the very low concentration of volatile solvent, the evaporation of which is further limited by the matrix. The optical transparency of the system also allows the restorer to continuously monitor the cleaning process.
“We successfully cleaned a mural from the 15th century,” reports Baglioni. This painting is located in the Santa Maria della Scala Sacristy in Siena. “It was covered with a 35 year old layer of acrylic from a previous restoration. Our new system allowed us to completely remove the undesirable shine. We were also able to clean another art work: a gilt frame from an 18th century painting.”
Author: Piero Baglioni, Università degli Studi di Firenze (Italy), http://matsci.unipv.it/CSGI/proc/People.aspx?ID=35
Title: Nanoscience for Art Conservation: Oil-in-Water Microemulsions Embedded in a Polymeric Network for the Cleaning of Works of Art
Angewandte Chemie International Edition, doi: 10.1002/anie.200904244
Piero Baglioni | Angewandte Chemie
Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel
The Nagoya Protocol Creates Disadvantages for Many Countries when Applied to Microorganisms
05.12.2016 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Information Technology
05.12.2016 | Earth Sciences