Tag Archives: University of Florence

Graphene in art preservation and restoration

A July 5, 2021 news item on phys.org announces a new technology for preserving and restoring your paintings,

The exposure of colors used in artworks to ultraviolet (UV) and visible light in the presence of oxidizing agents triggers color degradation, fading and yellowing. These degradation mechanisms can lead to irreversible alteration of artworks. Protective varnishes and coatings currently used to protect art paintings are not acceptable solutions, since their removal requires the use of solvents, which can affect adversely the underlying work surface.

A team of researchers from the Institute of Chemical Engineering Sciences of Foundation for Research and Technology-Hellas (FORTH/ ICE-HT), the Department of Chemical Engineering of the University of Patras, and the Center for Colloid and Surface Science (CSGI) of the University of Florence, led by Professor Costas Galiotis, had the innovative ideato use graphene veils for the protection of paintings against environmental degradation.

A July 2, 2021 Foundation for Research and Technology – Hellas (FORTH) press release, which originated the news item, provides more details,

Since its isolation in 2004 by Geim [Andre Geim] and Novoselov [Konstantin Novoselov] from the University of Manchester (Nobel Prize in Physics in 2010), graphene has been termed as a ‘wonder material’ due to its exceptional properties that have already been used in many applications and products. The graphene veil used in this work is a flexible, transparent film, produced by the technique of chemical vapor deposition. It has a monoatomic thickness and, since there are no size limitations in the other dimensions (length and width), it can cover any required large surface areas.

The results from measurements performed in the above mentioned laboratories, showed that this membrane is impermeable to moisture, the oxidizing agents and other harmful pollutants and also can absorb a large amount of harmful ultraviolet radiation. Finally, in contrast to other protective means, it is demonstrated that these graphene coatings are relatively easy to remove without damaging the surface of the artworks.

[downloaded from https://phys.org/news/2021-07-graphene-paving-methods-art.html]

Before getting to the link and citation for the paper, here’s the abstract, which helps fill n a few more details,

Modern and contemporary art materials are generally prone to irreversible colour changes upon exposure to light and oxidizing agents. Graphene can be produced in thin large sheets, blocks ultraviolet light, and is impermeable to oxygen, moisture and corrosive agents; therefore, it has the potential to be used as a transparent layer for the protection of art objects in museums, during storage and transportation. Here we show that a single-layer or multilayer graphene veil, produced by chemical vapour deposition, can be deposited over artworks to protect them efficiently against colour fading, with a protection factor of up to 70%. We also show that this process is reversible since the graphene protective layer can be removed using a soft rubber eraser without causing any damage to the artwork. We have also explored a complementary contactless graphene-based route for colour protection that is based on the deposition of graphene on picture framing glass for use when the directapplication of graphene is not feasible due to surface roughness or artwork fragility. Overall, the present results are a proof of concept of the potential use of graphene as an effective and removable protective advanced material to prevent colour fading in artworks.

And now, a link to and a citation for the paper,

Preventing colour fading in artworks with graphene veils by M. Kotsidi, G. Gorgolis, M. G. Pastore Carbone, G. Anagnostopoulos, G. Paterakis, G. Poggi, A. Manikas, G. Trakakis, P. Baglioni & C. Galiotis. Nature Nanotechnology (2021) DOI: https://doi.org/10.1038/s41565-021-00934-z Published 01 July 2021

This paper is behind a paywall.

Removing vandals’ graffiti from street art with nanotechnology-enabled method and Happy Italian Research in the World Day and more …

Happy Italian Research in the World Day! Each year since 2018 this has been celebrated on the day that Leonardo da Vinci was born over 500 years ago on April 15. It’s also the start of World Creativity and Innovation Week (WCIW), April 15 – 21, 2021 with over 80 countries (Italy, The Gambia, Mauritius, Belarus, Iceland, US, Syria, Vietnam, Indonesia, Denmark, etc.) celebrating. By the way, April 21, 2021 is the United Nations’ World Creativity and Innovation Day. Now, onto some of the latest research, coming from Italy, on art conservation.

There’s graffiti and there’s graffiti as Michele Baglioni points out in an April 13, 2021 American Chemical Society (ACS) press conference (Rescuing street art from vandals’ graffiti) held during the ACS Spring 2021 Meeting being held online April 5-30, 2021.

An April 13, 2021 news item on ScienceDaily announced the research,

From Los Angeles and the Lower East Side of New York City to Paris and Penang, street art by famous and not-so-famous artists adorns highways, roads and alleys. In addition to creating social statements, works of beauty and tourist attractions, street art sometimes attracts vandals who add their unwanted graffiti, which is hard to remove without destroying the underlying painting. Now, researchers report novel, environmentally friendly techniques that quickly and safely remove over-paintings on street art.

A new eco-friendly method can remove the graffiti that this person is about to spray on the street art behind them. Credit: FOTOKITA/Shutterstock.com

An April 13, 2021 ACS news release (also on EurekAlert), which originated the news item, provides details about this latest work and how it fits into the field of art conservation,

“For decades, we have focused on cleaning or restoring classical artworks that used paints designed to last centuries,” says Piero Baglioni, Ph.D., the project’s principal investigator. “In contrast, modern art and street art, as well as the coatings and graffiti applied on top, use materials that were never intended to stand the test of time.”

Research fellow Michele Baglioni, Ph.D., (no relation to Piero Baglioni) and coworkers built on their colleagues’ work and designed a nanostructured fluid, based on nontoxic solvents and surfactants, loaded in highly retentive hydrogels that very slowly release cleaning agents to just the top layer — a few microns in depth. The undesired top layer is removed in seconds to minutes, with no damage or alteration to the original painting.

Street art and overlying graffiti usually contain one or more of three classes of paint binders — acrylic, vinyl or alkyd polymers. Because these paints are similar in composition, removing the top layer frequently damages the underlying layer. Until now, the only way to remove unwanted graffiti was by using chemical cleaners or mechanical action such as scraping or sand blasting. These traditional methods are hard to control and often damaged the original art.

“We have to know exactly what is going on at the surface of the paintings if we want to design cleaners,” explains Michele Baglioni, who is at the University of Florence (Italy). “In some respects, the chemistry is simple — we are using known surfactants, solvents and polymers. The challenge is combining them in the right way to get all the properties we need.”

Michele Baglioni and coworkers used Fourier transform infrared spectroscopy to characterize the binders, fillers and pigments in the three classes of paints. After screening for suitable low-toxicity, “green” solvents and biodegradable surfactants, he used small angle X-ray scattering analyses to study the behavior of four alkyl carbonate solvents and a biodegradable nonionic surfactant in water.

The final step was formulating the nanostructured cleaning combination. The system that worked well also included 2-butanol and a readily biodegradable alkyl glycoside hydrotrope as co-solvents/co-surfactants. Hydrotropes are water-soluble, surface-active compounds used at low levels that allow more concentrated formulations of surfactants to be developed. The system was then loaded into highly retentive hydrogels and tested for its ability to remove overpaintings on laboratory mockups using selected paints in all possible combinations.

After dozens of tests, which helped determine how long the gel should be applied and removed without damaging the underlying painting, he tested the gels on a real piece of street art in Florence, successfully removing graffiti without affecting the original work.

“This is the first systematic study on the selective and controlled removal of modern paints from paints with similar chemical composition,” Michele Baglioni says. The hydrogels can also be used for the removal of top coatings on modern art that were originally intended to preserve the paintings but have turned out to be damaging. The hydrogels will become available commercially from CSGI Solutions for Conservation of Cultural Heritage, a company founded by Piero Baglioni and others. CSGI, the Center for Colloid and Surface Science, is a university consortium mainly funded through programs of the European Union.

And, there was this after the end of the news release,

The researchers acknowledge support and funding from the European Union NANORESTART (Nanomaterials for the Restoration of Works of Art) Program [or NanoRestArt] and CSGI.

The NanoRestArt project has been mentioned here a number of times,

The project ended in November 2018 but the NanoRestArt website can still be accessed.

The Leonardo Project and the master’s DNA (deoxyribonucleic acid)

I’ve never really understood the mania for digging up bodies of famous people in history and trying to ascertain how the person really died or what kind of diseases they may have had but the practice fascinates me. The latest famous person to be subjected to a forensic inquiry centuries after death is Leonardo da Vinci. A May 5, 2016 Human Evolution (journal) news release on EurekAlert provides details,

A team of eminent specialists from a variety of academic disciplines has coalesced around a goal of creating new insight into the life and genius of Leonardo da Vinci by means of authoritative new research and modern detective technologies, including DNA science.

The Leonardo Project is in pursuit of several possible physical connections to Leonardo, beaming radar, for example, at an ancient Italian church floor to help corroborate extensive research to pinpoint the likely location of the tomb of his father and other relatives. A collaborating scholar also recently announced the successful tracing of several likely DNA relatives of Leonardo living today in Italy (see endnotes).

If granted the necessary approvals, the Project will compare DNA from Leonardo’s relatives past and present with physical remnants — hair, bones, fingerprints and skin cells — associated with the Renaissance figure whose life marked the rebirth of Western civilization.

The Project’s objectives, motives, methods, and work to date are detailed in a special issue of the journal Human Evolution, published coincident with a meeting of the group hosted in Florence this week under the patronage of Eugenio Giani, President of the Tuscan Regional Council (Consiglio Regionale della Toscana).

The news release goes on to provide some context for the work,

Born in Vinci, Italy, Leonardo died in 1519, age 67, and was buried in Amboise, southwest of Paris. His creative imagination foresaw and described innovations hundreds of years before their invention, such as the helicopter and armored tank. His artistic legacy includes the iconic Mona Lisa and The Last Supper.

The idea behind the Project, founded in 2014, has inspired and united anthropologists, art historians, genealogists, microbiologists, and other experts from leading universities and institutes in France, Italy, Spain, Canada and the USA, including specialists from the J. Craig Venter Institute of California, which pioneered the sequencing of the human genome.

The work underway resembles in complexity recent projects such as the successful search for the tomb of historic author Miguel de Cervantes and, in March 2015, the identification of England’s King Richard III from remains exhumed from beneath a UK parking lot, fittingly re-interred 500 years after his death.

Like Richard, Leonardo was born in 1452, and was buried in a setting that underwent changes in subsequent years such that the exact location of the grave was lost.

If DNA and other analyses yield a definitive identification, conventional and computerized techniques might reconstruct the face of Leonardo from models of the skull.”

In addition to Leonardo’s physical appearance, information potentially revealed from the work includes his ancestry and additional insight into his diet, state of health, personal habits, and places of residence.

According to the news release, the researchers have an agenda that goes beyond facial reconstruction and clues about  ancestry and diet,

Beyond those questions, and the verification of Leonardo’s “presumed remains” in the chapel of Saint-Hubert at the Château d’Amboise, the Project aims to develop a genetic profile extensive enough to understand better his abilities and visual acuity, which could provide insights into other individuals with remarkable qualities.

It may also make a lasting contribution to the art world, within which forgery is a multi-billion dollar industry, by advancing a technique for extracting and sequencing DNA from other centuries-old works of art, and associated methods of attribution.

Says Jesse Ausubel, Vice Chairman of the Richard Lounsbery Foundation, sponsor of the Project’s meetings in 2015 and 2016: “I think everyone in the group believes that Leonardo, who devoted himself to advancing art and science, who delighted in puzzles, and whose diverse talents and insights continue to enrich society five centuries after his passing, would welcome the initiative of this team — indeed would likely wish to lead it were he alive today.”

The researchers aim to have the work complete by 2019,

In the journal, group members underline the highly conservative, precautionary approach required at every phase of the Project, which they aim to conclude in 2019 to mark the 500th anniversary of Leonardo’s death.

For example, one objective is to verify whether fingerprints on Leonardo’s paintings, drawings, and notebooks can yield DNA consistent with that extracted from identified remains.

Early last year, Project collaborators from the International Institute for Humankind Studies in Florence opened discussions with the laboratory in that city where Leonardo’s Adoration of the Magi has been undergoing restoration for nearly two years, to explore the possibility of analyzing dust from the painting for possible DNA traces. A crucial question is whether traces of DNA remain or whether restoration measures and the passage of time have obliterated all evidence of Leonardo’s touch.

In preparation for such analysis, a team from the J. Craig Venter Institute and the University of Florence is examining privately owned paintings believed to be of comparable age to develop and calibrate techniques for DNA extraction and analysis. At this year’s meeting in Florence, the researchers also described a pioneering effort to analyze the microbiome of a painting thought to be about five centuries old.

If human DNA can one day be obtained from Leonardo’s work and sequenced, the genetic material could then be compared with genetic information from skeletal or other remains that may be exhumed in the future.

Here’s a list of the participating organizations (from the news release),

  • The Institut de Paléontologie Humaine, Paris
  • The International Institute for Humankind Studies, Florence
  • The Laboratory of Molecular Anthropology and Paleogenetics, Biology Department, University of Florence
  • Museo Ideale Leonardo da Vinci, in Vinci, Italy
  • J. Craig Venter Institute, La Jolla, California
  • Laboratory of Genetic Identification, University of Granada, Spain
  • The Rockefeller University, New York City

You can find the special issue of Human Evolution (HE Vol. 31, 2016 no. 3) here. The introductory essay is open access but the other articles are behind a paywall.

NanoForArt in Mexico

Mexico recently hosted (Feb. 7 – 8, 2013) a pair of conferences focused on nanotechnology and art conservation. The country is part of an international consortium in the European Commision’s Seventh Framework Programme (FP7), NanoForArt project. Before mentioning the conference, here’s a little information about the NanoForArt project from its homepage,

The main objective of the NANOFORART proposal is the development and experimentation of new nano-materials and responsive systems for the conservation and preservation of movable and immovable artworks. [emphasis mine]

While the progress in material science has generated sophisticated nanostructured materials, conservation of cultural heritage is still mainly based on traditional methods and conventional materials that often lack the necessary  compatibility with the original artworks and a durable performance in responding to the changes of natural environment and man-made activities.

The main challenge of NANOFORART is the combination of sophisticated functional materials arising from the recent developments in nano-science/technology with innovative techniques in the restoration and preventive conservation of works of art, with unprecedented efficiency.

Immovable artworks tend to be things like cave art, frescoes, and other forms of wall and rock art. The Feb. 2013 conferences in Mexico as per a Feb. 27, 2013 Agencia EFE news item on the Global Post website featured (Note: Links have been removed),

Baglioni [Piero Baglioni, a researcher and professor at the University of Florence] and Dr. Rodorico Giorgi, also of the University of Florence, traveled to Mexico earlier this month to preside over a conference on Nanotechnology applied to cultural heritage: wall paintings/cellulose, INAH [Instituto Nacional de Antropología e Historia] said.

The project includes specialists from Italy, Spain, Britain, France, Denmark, the Czech Republic, Germany,  Slovenia and Mexico and is coordinated by the CSGI center [Center for Colloids and Surface Science] at the University of Florence.

NANONFORART is set to conclude in December 2014 with the “validation of the technology and the methods developed, as well as training activities,” INAH said.

Until now, preservation of cultural treasures has been carried out using conventional materials that are often incompatible with the works and can, over time, alter the appearance of the object.

Baglioni has worked with INAH personnel to clean and restore pre-Columbian murals at the Cacaxtla, Cholula, Tlatelolco, Mayapan, El Tajin, Monte Alban and Teotihuacan sites.

I have mentioned Baglioni’s work in Mexico previously in a Sept. 20, 2010 posting about  some work at La Antigua Ciudad Maya de Calakmul, an archaeological site which is located in the Campeche state.

Unfortunately, there aren’t too many details about the conferences, the Feb. 7, 2013 conference sported the previously noted title (in the Agencia EFE news item), Nanotechnology Applied to Cultural Heritage: Wall Paintings/Cellulose, and the Feb. 8, 2013 conference was titled, Nanotechnology for the Cleaning of Cultural Heritage.

There’s more information about nanotechnology aspects on the NanoForArt Overall page (Note: Links have been removed),

The work plan will start with design and formulation of nanostructured systems with special functionalities (WP1) such as deacidification of movable artworks (paper, parchment, canvas, leather), cleaning of movable artworks (paper, parchment, canvas paintings), protection of movable artworks (paper, canvas), consolidation of immovable artworks (wall-paintings, plaster and stones), and cleaning of immovable artworks (wallpaintings, plaster and stones). These systems, whose formulation will be optimized according to their functions, will include microemulsions, micellar solutions, gels and dispersions of different kinds of nanoparticles. A physico-chemical characterization of the developed materals (WP2) will constantly support the formulation activity. This will allow to understand and control the nature of interaction mechanisms between these nanostructures and the target substances/supports.

Assessment of the applicability of materials (WP3) will start in the second half of the first year. In this phase the up-scale of the technologies from the laboratory to the market level will be tackled. All the partners will interact in order to clarify and merge the priority from all the points of view. Evaluation of possible human health effects and environmental impacts of developed nanomaterials for restoration (WP7) will also start in the second half of the first year. Special emphasis will be given to potential hazardousness of nanoparticles used for design and formulation of nanostructured systems, as well as environmental impacts associated with the use of these nano-based products.

Nanotechnology developed by NANOFORART will aim also to significantly reduce the use of harmful solvents, as well as to introduce new environmentally friendly nanomaterials. Once the applicability and safety of the developed materials will be assessed, the development of industry process (WP4, WP5) will start in order to transfer technology on the market by the standardization of the applicative protocols and production of the nanomaterials on medium and large scale. Small and Medium Enterprise (SME) partners will have their main competence in this phase, that should start at the beginning of the second year. Safety and health risks of the industry processes will be also assessed. At the end of the first year, a study of the long-term behavior of the products and of the treated works of art (WP6) will be started by means of artificial ageing, in order to avoid damages due to unforeseen phenomena. The partners will have their main competence in ageing, monitoring of environmental pollution, and control of exhibitions and museums conditions.

The project is scheduled for completion in 2014.

The aspect I find most interesting is the ‘immovable art’. There was a controversy in Spain in 2011 over the prospect of opening some caves to tourists, from the Oct. 26, 2011 news item on ScienceDaily,

Plans to reopen Spain’s Altamira caves are stirring controversy over the possibility that tourists’ visits will further damage the 20,000-year old wall paintings that changed views about the intellectual ability of prehistoric people. That’s the topic of an article in the current edition of Chemical & Engineering News, ACS’ weekly newsmagazine. The caves are the site of Stone Age paintings so magnificent that experts have called them the “Sistine Chapel of Paleolithic Art.”

Carmen Drahl, C&EN associate editor, points out in the article that Spanish officials closed the tourist mecca to the public in 2002 after scientists realized that visitors were fostering growth of bacteria that damage the paintings. Now, however, they plan to reopen the caves. Declared a World Heritage Site by the United Nations’ Educational, Scientific and Cultural Organization (UNESCO), Altamira’s rock paintings of animals and human hands made scientists realize that Stone Age people had intellectual capabilities far greater than previously believed.

You can find an Oct. 6, 2011 piece about the Altamira rock paintings by Drahl titled, Keeping Visitors Out To Keep Cave Paintings Safe, on the Chemical and Engineering News (C&EN) blog. For anyone interested in more about rock art, there’s a UNESCO (United Nations Educational, Scientific, and Cultural Organization) World Rock Archives project or, as they call them, activity,

Due to their long sequence chronology, susceptibility to climate changes and vandalism, rock art sites are also among the most vulnerable on the World Heritage List.

Rock art, in the form of paintings and engravings, is a clear and lasting evidence of the transmission of human thoughts and beliefs through art and graphic representations. It functions as a repository of memory, enabling each culture to speak about themselves and their origins in all geographical settings.

I have two more items on cave art. The first is a piece I’ve been wanting to feature for almost two years. It’s an article on Slate by John Jeremiah Sullivan dated March 21, 2011 and titled, America’s Ancient Cave Art
Deep in the Cumberland Plateau, mysterious drawings, thousands of years old, offer a glimpse of lost Native American cultures and traditions. It’s an excerpt of an essay Sullivan wrote for the Paris Review. A fascinating exploration of a cave system that isn’t nearly as well known as France’s Lascaux Caves, here’s a snippet,

Over the past few decades, in Tennessee, archaeologists have unearthed an elaborate cave­-art tradition thousands of years old. The pictures are found in dark­ zone sites—places where the Native American people who made the artwork did so at personal risk, crawling meters or, in some cases, miles underground with cane torches—as opposed to sites in the “twilight zone,” speleologists’ jargon for the stretch, just beyond the entry chamber, which is exposed to diffuse sunlight. A pair of local hobby cavers, friends who worked for the U.S. Forest Service, found the first of these sites in 1979. They’d been exploring an old root cellar and wriggled up into a higher passage. The walls were covered in a thin layer of clay sediment left there during long­ ago floods and maintained by the cave’s unchanging temperature and humidity. The stuff was still soft. It looked at first as though someone had finger­-painted all over, maybe a child—the men debated even saying anything. But the older of them was a student of local history. He knew some of those images from looking at drawings of pots and shell ornaments that emerged from the fields around there: bird men, a dancing warrior figure, a snake with horns. Here were naturalistic animals, too: an owl and turtle. Some of the pictures seemed to have been first made and then ritually mutilated in some way, stabbed or beaten with a stick.

That was the discovery of Mud Glyph Cave, which was reported all over the world and spawned a book and a National Geographic article. No one knew quite what to make of it at the time. The cave’s “closest parallel,” reported the Christian Science Monitor, “may be caves in the south of France which contain Ice Age art.” A team of scholars converged on the site.

The sites range from Missouri to Virginia, and from Wisconsin to Florida, but the bulk lie in Middle Tennessee. Of those, the greater number are on the Cumberland Plateau, which runs at a southwest slant down the eastern part of the state, like a great wall dividing the Appalachians from the interior.

If you do decide to read the excerpt, you may want to reserve 30 to 45 minutes (at least).

For the last tidbit, here’s an introduction to TED (Technology, Entertainment and Design) Fellow, Genevieve von Petzinger’s work on cave art,

Genevieve von Petzinger’s [from the University of Victoria in British Columbia, Canada] database of prehistoric geometric shapes in cave art reveals some startling insights. More than mere doodles, the signs used across geological boundaries suggest there may have been a common iconography before people first moved out of Africa. When did people begin graphic communication, and what was its purpose? Genevieve studies these questions of our common heritage.

A very interesting interview follows that introduction.

As I more often cover movable art, I thought it was time to devote, again, at least part of a posting to immovable art.

Nanoparticles, art conservation, and cultural heritage

Piero Baglioni, a professor of Physical Chemistry at the University of Florence (whose work was mentioned previously in my October 26, 2009 posting) spoke at the 3rd EuCheMS Chemistry Congress: Chemistry – the Creative Force, August 29 – September 2, 2010, Nürnberg / Germany about his team’s to better preserve wall paintings at a site in Mexico. From the news item on physorg.com,

La Antigua Ciudad Maya de Calakmul is located in the Campeche state (Mexico) and is one of the most important cities of the Classic Maya period (AD 250-800). The excavation of this site (set up in 1993) involves, under the supervision of the archaeologist Ramon Carrasco, archaeologists, architects, engineers, conservators and epigraphists, besides other specialists. Since 2004, the Center for Colloid and Surface Science (CSGI) at the University of Florence (CSGI), and currently directed by Piero Baglioni, has been an active partner, being involved in the study of the painting technique and in the development of nanotechnology for the consolidation and protection of the wall paintings and limestone.

There is a published article available in Chemistry: A European Journal,

Nanoparticles for Cultural Heritage Conservation: Calcium and Barium Hydroxide Nanoparticles for Wall Painting Consolidation.

Authors:
1. Rodorico Giorgi Dr.,
2. Moira Ambrosi Dr.,
3. Nicola Toccafondi Dr.,
4. Piero Baglioni Prof.

Article first published online: 23 JUL 2010
DOI: 10.1002/chem.201001443

The article is freely available at this time. If you’re interested in this history of the mural, there’s an article (Chemical & Engineering News, Central Science)by Sarah Everts,

Sometime before 600 BC, Mayan artists painted one of the few frescoes–still in existence–that displays the domestic life of normal people in this ancient civilization (other Mayan frescoes display the lives of deities and rulers). The frescoes were found in a pyramid at the Calakmul archaeology site in Mexico. Calakmul is one of the biggest Mayan sites around, but it hasn’t been excavated to the same extent as say, Tikal, which had a cameo in “Return of the Jedi” as the Ewok planet and is also host to a constant throng of tourists.

I expect there’ll be more about nanotechnology and art conservation as time goes on, the promise being that taking samples and working at the nanoscale promises to minimize damage of an art piece we are trying to preserve.

ETA: I forgot to include the recent McGill University research on a photoacoustic technique for art restoration in my Sept. 2, 2010 posting.