Tag Archives: art preservation

Historic and other buildings get protection from pollution?

This Sept. 15, 2017 news item on Nanowerk announces a new product for protecting buildings from pollution,

The organic pollution decomposing properties of titanium dioxide (TiO2 ) have been known for about half a century. However, practical applications have been few and hard to develop, but now a Greek paint producer claims to have found a solution

A Sept. 11, 2017 Youris (European Research Media Center) press release by Koen Mortelmans which originated the news item expands on the theme,

The photocatalytic properties of anatase, one of the three naturally occurring forms of titanium dioxide, were discovered in Japan in the late 1960s. Under the influence of the UV-radiation in sunlight, it can decompose organic pollutants such as bacteria, fungi and nicotine, and some inorganic materials into carbon dioxide. The catalytic effect is caused by the nanostructure of its crystals.

Applied outdoors, this affordable and widely available material could represent an efficient self-cleaning solution for buildings. This is due to the chemical reaction, which leaves a residue on building façades, a residue then washed away when it rains. Applying it to monuments in urban areas may save our cultural heritage, which is threatened by pollutants.

However, “photocatalytic paints and additives have long been a challenge for the coating industry, because the catalytic action affects the durability of resin binders and oxidizes the paint components,” explains Ioannis Arabatzis, founder and managing director of NanoPhos, based in the Greek town of Lavrio, in one of the countries home to some of the most important monuments of human history. The Greek company is testing a paint called Kirei, inspired by a Japanese word meaning both clean and beautiful.

According to Arabatzis, it’s an innovative product because it combines the self-cleaning action of photocatalytic nanoparticles and the reflective properties of cool wall paints. “When applied on exterior surfaces this paint can reflect more than 94% of the incident InfraRed radiation (IR), saving energy and reducing costs for heating and cooling”, he says. “The reflection values are enhanced by the self-cleaning ability. Compared to conventional paints, they remain unchanged for longer.”

The development of Kirei has been included in the European project BRESAER (BREakthrough Solutions for Adaptable Envelopes in building Refurbishment) which is studying a sustainable and adaptable “envelope system” to renovate buildings. The new paint was tested and subjected to quality controls following ISO standard procedures at the company’s own facilities and in other independent laboratories. “The lab results from testing in artificial, accelerated weathering conditions are reliable,” Arabatzis claims. “There was no sign of discolouration, chalking, cracking or any other paint defect during 2,000 hours of exposure to the simulated environmental conditions. We expect the coating’s service lifetime to be at least ten years.”

Many studies are being conducted to exploit the properties of titanium dioxide. Jan Duyzer, researcher at the Netherlands Organisation for Applied Scientific Research (TNO) in Utrecht, focused on depollution: “There is no doubt about the ability of anatase to decrease the levels of nitrogen oxides in the air. But in real situations, there are many differences in pollution, wind, light, and temperature. We were commissioned by the Dutch government specifically to find a way to take nitrogen oxides out of the air on roads and in traffic tunnels. We used anatase coated panels. Our results were disappointing, so the government decided to discontinue the research. Furthermore, we still don’t know what caused the difference between lab and life. Our best current hypothesis is that the total surface of the coated panels is very small compared to the large volumes of polluted air passing over them,” he tells youris.com.

Experimental deployment of titanium dioxide panels on an acoustic wall along a Dutch highway – Courtesy of Netherlands Organisation for Applied Scientific Research (TNO)

“In laboratory conditions the air is blown over the photocatalytic surface with a certain degree of turbulence. This results in the NOx-particles and the photocatalytic material coming into full contact with one another,” says engineer Anne Beeldens, visiting professor at KU Leuven, Belgium. Her experience with photocatalytic TiO2 is also limited to nitrogen dioxide (NOx) pollution.

In real applications, the air stream at the contact surface becomes laminar. This results in a lower velocity of the air at the surface and a lower depollution rate. Additionally, not all the air will be in contact with the photocatalytic surfaces. To ensure a good working application, the photocatalytic material needs to be positioned so that all the air is in contact with the surface and flows over it in a turbulent manner. This would allow as much of the NOx as possible to be in contact with photocatalytic material. In view of this, a good working application could lead to a reduction of 5 to 10 percent of NOx in the air, which is significant compared to other measures to reduce pollutants.”

The depollution capacity of TiO2 is undisputed, but most applications and tests have only involved specific kinds of substances. More research and measurements are required if we are to benefit more from the precious features of this material.

I think the most recent piece here on protecting buildings, i.e., the historic type, from pollution is an Oct. 21, 2014 posting: Heart of stone.

When based on plastic materials, contemporary art can degrade quickly

There’s an intriguing April 1, 2016 article by Josh Fischman for Scientific American about a problem with artworks from the 20th century and later—plastic-based materials (Note: A link has been removed),

Conservators at museums and art galleries have a big worry. They believe there is a good chance the art they showcase now will not be fit to be seen in one hundred years, according to researchers in a project  called Nanorestart. Why? After 1940, artists began using plastic-based material that was a far cry from the oil-based paints used by classical painters. Plastic is also far more fragile, it turns out. Its chemical bonds readily break. And they cannot be restored using techniques historically relied upon by conservators.

So art conservation scientists have turned to nanotechnology for help.

Sadly, there isn’t any detail in Fischman’s article (*ETA June 17, 2016 article [for Fast Company] by Charlie Sorrel, which features some good pictures, a succinct summary of Fischman’s article and a literary reference [Kurt Vonnegut’s Bluebeard]I*) about how nanotechnology is playing or might play a role in this conservation effort. Further investigation into the two projects (NanoRestART and POPART) mentioned by Fischman didn’t provide much more detail about NanoRestART’s science aspect but POPART does provide some details.

NanoRestART

It’s probably too soon (this project isn’t even a year-old) to be getting much in the way of the nanoscience details but NanoRestART has big plans according to its website homepage,

The conservation of this diverse cultural heritage requires advanced solutions at the cutting edge of modern chemistry and material science in an entirely new scientific framework that will be developed within NANORESTART project.

The NANORESTART project will focus on the synthesis of novel poly-functional nanomaterials and on the development of highly innovative restoration techniques to address the conservation of a wide variety of materials mainly used by modern and contemporary artists.

In NANORESTART, enterprises and academic centers of excellence in the field of synthesis and characterization of nano- and advanced materials have joined forces with complementary conservation institutions and freelance restorers. This multidisciplinary approach will cover the development of different materials in response to real conservation needs, the testing of such materials, the assessment of their environmental impact, and their industrial scalability.

NanoRestART’s (NANOmaterials for the REStoration of works of ART) project page spells out their goals in the order in which they are being approached,

The ground-breaking nature of our research can be more easily outlined by focussing on specific issues. The main conservation challenges that will be addressed in the project are:

 

Conservation challenge 1Cleaning of contemporary painted and plastic surfaces (CC1)

Conservation challenge 2Stabilization of canvases and painted layers in contemporary art (CC2)

Conservation challenge 3Removal of unwanted modern materials (CC3)

Conservation challenge 4Enhanced protection of artworks in museums and outdoors (CC4)

The European Commission provides more information about the project on its CORDIS website’s NanoRestART webpage including the start and end dates for the project and the consortium members,

From 2015-06-01 to 2018-12-01, ongoing project

CHALMERS TEKNISKA HOEGSKOLA AB
Sweden
MIRABILE ANTONIO
France
NATIONALMUSEET
Denmark
CONSIGLIO NAZIONALE DELLE RICERCHE
Italy
UNIVERSITY COLLEGE CORK, NATIONAL UNIVERSITY OF IRELAND, CORK
Ireland
MBN NANOMATERIALIA SPA
Italy
KEMIJSKI INSTITUT
Slovenia
CHEVALIER AURELIA
France
UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL
Brazil
UNIVERSITA CA’ FOSCARI VENEZIA
Italy
AKZO NOBEL PULP AND PERFORMANCE CHEMICALS AB
Sweden
COMMISSARIAT A L ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
France
ARKEMA FRANCE SA
France
UNIVERSIDAD DE SANTIAGO DE COMPOSTELA
Spain
UNIVERSITY COLLEGE LONDON
United Kingdom
ZFB ZENTRUM FUR BUCHERHALTUNG GMBH
Germany
UNIVERSITAT DE BARCELONA
Spain
THE BOARD OF TRUSTEES OF THE TATE GALLERY
United Kingdom
ASSOCIAZIONE ITALIANA PER LA RICERCA INDUSTRIALE – AIRI
Italy
THE ART INSTITUTE OF CHICAGO
United States
MINISTERIO DE EDUCACION, CULTURA Y DEPORTE
Spain
STICHTING HET RIJKSMUSEUM
Netherlands
UNIVERSITEIT VAN AMSTERDAM
Netherlands
UNIVERSIDADE FEDERAL DO RIO DE JANEIRO
Brazil
ACCADEMIA DI BELLE ARTI DI BRERA
Italy

It was a bit surprising to see Brazil and the US as participants but The Art Institute of Chicago has done nanotechnology-enabled conservation in the past as per my March 24, 2014 posting about a Renoir painting. I’m not familiar with the Brazilian organization.

POPART

POPART (Preservation of Plastic Artefacts in museum collections) mentioned by Fischman was a European Commission project which ran from 2008 – 2012. Reports can be found on the CORDIS Popart webpage. The final report has some interesting bits (Note: I have added subheads in the [] square brackets),

To achieve a valid comparison of the various invasive and non-invasive techniques proposed for the identification and characterisation of plastics, a sample collection (SamCo) of plastics artefacts of about 100 standard and reference plastic objects was gathered. SamCo was made up of two kinds of reference materials: standards and objects. Each standard represents the reference material of a ‘pure’ plastic; while each object represents the reference of the same plastic as in the standards, but compounded with pigments, dyestuffs, fillers, anti oxidants, plasticizers etc.  Three partners ICN [Instituut Collectie Nederland], V&A [Victoria and Albert Museum] and Natmus [National Museet] collected different natural and synthetic plastics from the ICN reference collections of plastic objects, from flea markets, antique shops and from private collections and from their own collection to contribute to SamCo, the sample collection for identification by POPART partners. …

As a successive step, the collections of the following museums were surveyed:

-Victoria & Albert Museum (V&A), London, U.K.
-Stedelijk Museum, Amsterdam, The Netherlands
-Musée d’Art Moderne et d’Art Contemporaine (MAMAC) Nice, France
-Musée d’Art moderne, St. Etienne, France
-Musée Galliera, Paris, France

At the V&A approximately 200 objects were surveyed. Good or fair conservation conditions were found for about 85% of the objects, whereas the remaining 15% was in poor or even in unacceptable (3%) conditions. In particular, crazing and delamination of polyurethane faux leather and surface stickiness and darkening of plasticized PVC were observed. The situation at the Stedelijk Museum in Amsterdam was particularly favourable because a previous survey had been done in 1995 so that it was possible to make a comparison with the Popart survey in 2010. A total number of 40 objects, which comprised plastics early dating from the 1930’s until the newer plastics from the 1980’s, were considered and their actual conservation state compared with the 1995 records. Of the objects surveyed in 2010, it can be concluded that 21 remained in the same condition. 13 objects containing PA, PUR, PVC, PP or natural rubber changed due to chemical and physical degradation while works of art containing either PMMA or PS changed due to mechanical damages and incorrect artist’s technique (inappropriate adhesive) into a lesser condition. 6 works of art (containing either PA or PMMA or both) changed into a better condition due to restoration or replacements.  More than 230 objects have been examined in the 3 museums in France. A particular effort was devoted to the identification of the constituting plastics materials. Surveys have been undertaken without any sophisticated equipment, in order to work in museums everyday conditions. Plastics hidden by other materials or by paint layers were not or hardly accessible, it is why the final count of some plastics may be under estimated in the final results. Another outcome is that plastic identification has been made at a general level only, by trying to identify the polymer family each plastic belongs to. Lastly, evidence of chemical degradation processes that do not cause visible or perceptible damage have not been detected and could not be taken in account in the final results.

… The most damaged artefacts resulted constituted by cellulose acetate, cellulose nitrate and PVC.

[Polly (the doll)]

One of the main issues that is of interest for conservators and curators is to assess which kinds of plastics are most vulnerable to deterioration and to what extent they can deteriorate under the environmental conditions normally encountered in museums. Although one might expect that real time deterioration could be ascertained by a careful investigation of museum objects on display or in storage, real objects or artworks may not sampled due to ethical considerations. Therefore, reference objects were prepared by Natmus in the form of a doll (Polly) for simultaneous exposures in different environmental conditions. The doll comprised of 11 different plastics representative of types typically found in modern museum collections. The 16 identical dolls realized were exposed in different places, not only in normal exhibit conditions, but also in some selected extreme conditions to ascertain possible acceleration of the deterioration process. In most cases the environmental parameters were also measured. The dolls were periodically evaluated by visual inspection and in selected cases by instrumental analyses. 

In conclusion the experimental campaign carried out with Polly dolls can be viewed as a pilot study aimed at tackling the practical issues related to the monitoring of real three dimensional plastic artworks and the surrounding environment.

The overall exposure period (one year and half) was sufficient to observe initial changes in the more susceptible polymers, such as polyurethane ethers and esters, and polyamide, with detectable chromatic changes and surface effects. Conversely the other polymers were shown to be stable in the same conditions over this time period.

[Polly as an awareness raising tool]

Last but not least, the educational and communication benefits of an object like Polly facilitated the dissemination of the Popart Project to the public, and increased the awareness of issues associated with plastics in museum collections.

[Cleaning issues]

Mechanical cleaning has long been perceived as the least damaging technique to remove soiling from plastics. The results obtained from POPART suggest that the risks of introducing scratches or residues by mechanical cleaning are measurable. Some plastics were clearly more sensitive to mechanical damage than others. From the model plastics evaluated, HIPS was the most sensitive followed by HDPE, PVC, PMMA and CA. Scratches could not be measured on XPS due to its inhomogeneous surfaces. Plasticised PVC scratched easily, but appeared to repair itself because plasticiser migrated to surfaces and filled scratches.

Photo micrographs revealed that although all 22 cleaning materials evaluated in POPART scratched test plastics, some scratches were sufficiently shallow to be invisible to the naked eye. Duzzit and Scotch Brite sponges as well as all paper based products caused more scratching of surfaces than brushes and cloths. Some cleaning materials, notably Akapad yellow and white sponges, compressed air, latex and synthetic rubber sponges and goat hair brushes left residues on surfaces. These residues were only visible on glass-clear, transparent test plastics such as PMMA. HDPE and HIPS surfaces both had matte and roughened appearances after cleaning with dry-ice. XPS was completely destroyed by the treatment. No visible changes were present on PMMA and PVC.

Of the cleaning methods evaluated, only canned air, natural and synthetic feather duster left surfaces unchanged. Natural and synthetic feather duster, microfiber-, spectacle – and cotton cloths, cotton bud, sable hair brush and leather chamois showed good results when applied to clean model plastics.

Most mechanical cleaning materials induced static electricity after cleaning, causing immediate attraction of dust. It was also noticed that generally when adding an aqueous cleaning agent to a cleaning material, the area scratched was reduced. This implied that cleaning agents also functioned as lubricants. A similar effect was exhibited by white spirit and isopropanol.
Based on cleaning vectors, Judith Hofenk de Graaff detergent, distilled water and Dehypon LS45 were the least damaging cleaning agents for all model plastics evaluated. None of the aqueous cleaning agents caused visible changes when used in combination with the least damaging cleaning materials. Sable hair brush, synthetic feather duster and yellow Akapad sponge were unsuitable for applying aqueous cleaning agents. Polyvinyl acetate sponge swelled in contact with solvents and was only suitable for aqueous cleaning processes.

Based on cleaning vectors, white spirit was the least damaging solvent. Acetone and Surfynol 61 were the most damaging for all model plastics and cannot be recommended for cleaning plastics. Surfynol 61 dissolved polyvinyl acetate sponge and left a milky residue on surfaces, which was particularly apparent on clear PMMA surfaces. Surfynol 61 left residues on surfaces on evaporating and acetone evaporated too rapidly to lubricate cleaning materials thereby increasing scratching of surfaces.

Supercritical carbon dioxide induced discolouration and mechanical damage to the model plastics, particularly to XPS, CA and PMMA and should not be used for conservation cleaning of plastics.

Potential Impact:
Cultural heritage is recognised as an economical factor, the cost of decay of cultural heritage and the risk associated to some material in collection may be high. It is generally estimated that plastics, developed at great numbers since the 20th century’s interbellum, will not survive that long. This means that fewer generations will have access to lasting plastic art for study, contemplation and enjoyment. On the other hand will it normally be easier to reveal a contemporary object’s technological secrets because of better documentation and easier access to artists’ working methods, ideas and intentions. A first more or less world encompassing recognition of the problems involved with museum objects made wholly or in part of plastics was through the conference ‘Saving the twentieth century” held in Ottawa, Canada in 1991. This was followed later by ‘Modern Art, who cares’ in Amsterdam, The Netherlands in 1997, ‘Mortality Immortality? The Legacy of Modern Art’ in Los Angeles, USA in 1998 and, for example much more recent, ‘Plastics –Looking at the future and learning from the Past’ in London, UK in 2007. A growing professional interest in the care of plastics was clearly reflected in the creation of an ICOM-CC working group dedicated to modern materials in 1996, its name change to Modern Materials and Contemporary Art in 2002, and its growing membership from 60 at inception to over 200 at the 16th triennial conference in Lisbon, Portugal in 2011 and tentatively to over 300 as one of the aims put forward in the 2011-2014 programme of that ICOM-CC working group. …

[Intellectual property]

Another element pertaining to conservation of modern art is the copyright of artists that extends at least 50 years beyond their death. Both, damage, value and copyright may influence the way by which damage is measured through scientific analysis, more specifically through the application of invasive or non invasive techniques. Any selection of those will not only have an influence on the extent of observable damage, but also on the detail of information gathered and necessary to explain damage and to suggest conservation measures.

[How much is deteriorating?]

… it is obvious from surveys carried out in several museums in France, the UK and The Netherlands that from 15 to 35 % of what I would then call an average plastic material based collection is in a poor to unacceptable condition. However, some 75 % would require cleaning,

I hope to find out more about how nanotechnology is expected to be implemented in the conservation and preservation of plastic-based art. The NanoRestART project started in June 2015 and hopefully more information will be disseminated in the next year or so.

While it’s not directly related, there was some work with conservation of daguerreotypes (19th century photographic technique) and nanotechnology mentioned in my Nov. 17, 2015 posting which was a followup to my Jan. 10, 2015 posting about the project and the crisis precipitating it.

*ETA June 30, 2016: Here’s clip from a BBC programme, Science in Action broadcast on June 30, 2016 featuring a chat with some of the scientists involved in the NanoRestArt project (Note: This excerpt is from a longer programme and seemingly starts in the middle of a conversation,)

Heart of stone

Researchers in Europe do not want to find out what would Europe look like without its stone castles, Stonehenge, Coliseum, cathedrals, and other monumental stone structures, and have found a possible solution to the problem of deterioration according to an Oct. 20, 2014 news item on Nanowerk,

Castles and cathedrals, statues and spires… Europe’s built environment would not be the same without these witnesses of centuries past. But, eventually, even the hardest stone will crumble. EU-funded researchers have developed innovative nanomaterials to improve the preservation of our architectural heritage.

“Our objective,” says Professor Gerald Ziegenbalg of IBZ Salzchemie, “was to find new possibilities to consolidate stone and mortar, especially in historical buildings.” The products available at the time, he adds, didn’t meet the full range of requirements, and some could actually damage the artefacts they were meant to preserve. Alternatives compatible with the original materials were needed.

A July 9, 2014 European Commission press release, which originated the news item, provides more details about this project (Note: A link has been removed),

 Ziegenbalg was the coordinator of the Stonecore project, which rose to this monumental challenge within a mere three years. It developed and commercialised a new type of material that penetrates right into the stone, protecting it without any risk of damage or harmful residues. The team also invented new ways to assess damage to stone and refined a number of existing techniques.

The concept behind the new material developed by the Stonecore partners is ingenious. It involves lime nanoparticles suspended in alcohol, a substance that evaporates completely upon exposure to air. The nanoparticles then react with carbon dioxide in the atmosphere to form limestone.

This innovation is on the market under the brand name CaLoSil. It is available in various consistencies – liquids and pastes – and in a number of formulations based on different types of alcohol, as well as with added filler materials such as marble. The product is applied by dipping, spraying or injection into the stone.

Beyond its use as a consolidant, CaLoSil can also be used to clean stone and mortar, as it helps to treat fungus and algae. The dehydrating effect of the alcohol and the acidity of the lime destroy the cells, and the growth can then be washed off. This method, says Ziegenbalg, is more effective than conventional chemical or mechanical approaches, and it does not damage the stone.

Limestone face-lifts

The partners tested their new product in a number of locations across Europe, on a wide variety of materials exposed to very different conditions. Together, they rejuvenated statues and sculptures, saved features in cathedrals and citadels, and treated materials as diverse as sandstone, marble and tuff.

The opportunity to access such a wide variety of sites, says Ziegenbalg, was one of the many advantages of working with partners from several countries. It pre-empted the risk of developing a product that was too narrowly focused on a specific application.

Inside the heart of stone

A number of techniques enable conservation teams to assess the state of the objects in their care. To obtain a clearer picture of deeper damage, Stonecore improved existing approaches involving ultrasound, developing a new device. The project also pioneered a new technique based on ground-penetrating radar, which one partner is now offering as a commercial service.

The team also developed an innovative micro-drilling tool and refined an existing technique for measuring the water uptake of stone.

A further innovation is a new technique to measure surface degradation. For this so-called “peeling test”, a length of adhesive tape is affixed to the object. The weight of the particles that come off with the tape when it is removed indicate how likely the stone is to degrade.

Carving out solutions

The partners’ achievements have not gone unnoticed. In 2013, Stonecore was shortlisted along with 10 other projects for the annual EuroNanoForum’s Best Project Award.

Ziegenbalg attributes the team’s success mainly to the partners’ wide range of complementary expertise, and to their dedication. “The participating small and medium-sized enterprises were extremely active,” he says. “They were highly motivated to handle the more practical work, while the universities supported them with the necessary research input.”

While it’s not clear from this press release or the Stonecore website, it appears this project has run its course as part of European Union’s Framework Programme 7.