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
MicroRNA helps cancer evade immune system
19.09.2017 | Salk Institute
Ruby: Jacobs University scientists are collaborating in the development of a new type of chocolate
18.09.2017 | Jacobs University Bremen gGmbH
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...
Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.
Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
19.09.2017 | Event News
19.09.2017 | Physics and Astronomy
19.09.2017 | Power and Electrical Engineering