Tag Archives: art conservation

Seeing ghosts: recovering images from dageurreotypes with help from the Canadian Light Source (synchrotron)

A daguerreotype plate with the photograph hidden by the tarnish (left) yet visible when imaged with synchrotron X-rays (right). Courtesy of Madalena Kozachuk.

Amazing, yes? Especially when you consider how devastating the inadvertent destruction of important daguerreotypes in an exhibition of US Civil War photography must have been to the curators and owners of the images. The ‘destruction’ occurred in 2005 and inspired research into the cause of the destruction, which was first covered here in a January 10, 2013 posting and followed up in a November 17, 2015 posting about an exhibit showcasing the results of the research.

A daguerreotype plate with the photograph hidden by the tarnish (left) yet visible when imaged with synchrotron X-rays (right). Courtesy of Madalena Kozachuk.

This latest research into daguerreotypes was performed at the Canadian Light Source (CLS; Saskatoon, Saskatchewan, Canada). Unlike my previous postings, this research was an attempt to retrieve the original image rather than research the reasons for its ‘destruction’. From a June 22, 2018 CLS news release (also on EurekAlert) by Lana Haight and Jeffrey Renaud (Note: Links have been removed),

Art curators will be able to recover images on daguerreotypes, the earliest form of photography that used silver plates, after scientists learned how to use light to see through degradation that has occurred over time.

Research published today [June 22, 2018] in Scientific Reports includes two images from the National Gallery of Canada’s photography research unit that show photographs that were taken, perhaps as early as 1850, but were no longer visible because of tarnish and other damage. The retrieved images, one of a woman and the other of a man, were beyond recognition.

“It’s somewhat haunting because they are anonymous and yet it is striking at the same time,” said Madalena Kozachuk, a PhD student in the Department of Chemistry at Western University [formerly University of Western Ontario] and lead author of the scientific paper.

“The image is totally unexpected because you don’t see it on the plate at all. It’s hidden behind time. But then we see it and we can see such fine details: the eyes, the folds of the clothing, the detailed embroidered patterns of the table cloth.”

The identities of the woman and the man are not known. It’s possible that the plates were produced in the United States, but they could be from Europe.

For the past three years, Kozachuk and an interdisciplinary team of scientists have been exploring how to use synchrotron technology to learn more about chemical changes that damage daguerreotypes.

Invented in 1839, daguerreotype images were created using a highly polished silver-coated copper plate that was sensitive to light when exposed to an iodine vapour. Subjects had to pose without moving for two to three minutes for the image to imprint on the plate, which was then developed as a photograph using a mercury vapour that was heated.

Kozachuk conducts much of her research at the Canadian Light Source and previously published results in scientific journals in 2017 and earlier this year. In those articles, the team members identified the chemical composition of the tarnish and how it changed from one point to another on a daguerreotype.

“We compared degradation that looked like corrosion versus a cloudiness from the residue from products used during the rinsing of the photographs versus degradation from the cover glass. When you look at these degraded photographs, you don’t see one type of degradation,” said Ian Coulthard, a senior scientist at the CLS and one of Kozachuk’s supervisors. He is also a co- author on the research papers.

This preliminary research at the CLS led to today’s [June 22, 2018] paper and the images Kozachuk collected at the Cornell High Energy Synchrotron Source where she was able to analyze the daguerreotypes in their entirety.

Kozachuk used rapid-scanning micro-X-ray fluorescence imaging to analyze the plates, which are about 7.5 cm wide, and identified where mercury was distributed on the plates. With an X-ray beam as small as 10 by 10 microns (a human scalp hair averages 75 microns across) and at an energy most sensitive to mercury absorption, the scan of each daguerreotype took about eight hours.

“Mercury is the major element that contributes to the imagery captured in these photographs. Even though the surface is tarnished, those image particles remain intact. By looking at the mercury, we can retrieve the image in great detail,” said Tsun-Kong (T.K.) Sham, Canada Research Chair in Materials and Synchrotron Radiation at Western University. He also is a co-author of the research and one of Kozachuk’s supervisors.

This is one of the many examples of successful research collaboration between Western University and CLS scientists.

Kozachuk’s research, which is ongoing, will contribute to improving how daguerreotype images are recovered when cleaning is possible and will provide a way to see what’s below the tarnish when cleaning is not possible. She will be back at the CLS this fall to continue her work.

The prospect of improved conservation methods intrigues John P. McElhone, recently retired as the chief of the Conservation and Technical Research branch at the Canadian Photography Institute of the National Gallery of Canada. He provided the daguerreotypes from the institute’s research collection.

“There are a lot of interesting questions that at this stage of our knowledge can only be answered by a sophisticated scientific approach,” said McElhone, another of the co-authors of today’s paper.

“A conservator’s first step is to have a full and complete understanding of what the material isand how it is assembled on a microscopic and even nanoscale level. We want to find out how the chemicals are arranged on the surface and that understanding gives us access to theories about how degradation happens and how that degradation can possibly or possibly not be reversed.”

As the first commercialized photographic process, the daguerreotype is thought to be the first “true” visual representation of history. Unlike painters who could use “poetic licence” in their work, the daguerreotype reflected precisely what was photographed.

Thousands and perhaps millions of daguerreotypes were created over 20 years in the 19th century before the process was replaced. The Canadian Photography Institute collection numbers more than 2,700, not including the daguerreotypes in the institute’s research collection.

By improving the process of restoring these centuries-old images, the scientists are contributing to the historical record. What was thought to be lost that showed the life and times of people from the 19th century can now be found. [emphases mine]

That last sentence seems to be borrowing from a line in the song, Amazing Grace, “I once was lost, but now am found,” from the song’s Wikipedia entry.

Here’s a link to and a citation for the paper,

Recovery of Degraded-Beyond-Recognition 19th Century Daguerreotypes with Rapid High Dynamic Range Elemental X-ray Fluorescence Imaging of Mercury L Emission by Madalena S. Kozachuk, Tsun-Kong Sham, Ronald R. Martin, Andrew J. Nelson, Ian Coulthard, & John P. McElhone. Scientific Reports volume 8, Article number: 9565 (2018) DOI:10.1038/s41598-018-27714 Published online June 22, 2018

This paper is open access. By the way, the research into the ‘destruction’ of the daguerreotypes in the 2005 exhibition? It’s cited in this paper.

Shipwrecks being brought back to life with ‘smart nanotech’

The American Chemical Society (ACS) is holding its 256th meeting from August 19 – 22, 2018 in Boston, Massachusetts, US. This August 21, 2018 news item on Nanowerk announces a ‘shipwreck’ presentation at the meeting,

Thousands of shipwrecks litter the seafloor all over the world, preserved in sediments and cold water. But when one of these ships is brought up from the depths, the wood quickly starts deteriorating. Today, scientists report a new way to use “smart” nanocomposites to conserve a 16th-century British warship, the Mary Rose, and its artifacts. The new approach could help preserve other salvaged ships by eliminating harmful acids without damaging the wooden structures themselves.

An August 21, 2018 ACS press release (also on EurekAlert), which originated the news item, delves further into the research and scientists’ after hours (?) activities,

“This project began over a glass of wine with Eleanor Schofield, Ph.D., who is head of conservation at the Mary Rose Trust,” recalls Serena Corr, Ph.D., the project’s principal investigator. “She was working on techniques to preserve the wood hull and assorted artifacts and needed a way to direct the treatment into the wood. We had been working with functional magnetic nanomaterials for applications in imaging, and we thought we might be able to apply this technology to the Mary Rose.”

The Mary Rose sank in 1545 off the south coast of England and remained under the seabed until she was salvaged in 1982, along with over 19,000 artifacts and pieces of timber. About 40 percent of the original structure survived. The ship and its artifacts give unique insights into Tudor seafaring and what it was like to live during that period. A state-of-the-art museum in Portsmouth, England, displays the ship’s hull and artifacts. A video about the ship and its artifacts can be viewed here.

While buried in the seabed, sulfur-reducing marine bacteria migrated into the wood of the Mary Rose and produced hydrogen sulfide. This gas reacted with iron ions from corroded fixtures like cannons to form iron sulfides. Although stable in low-oxygen environments, sulfur rapidly oxidizes in regular air in the presence of iron to form destructive acids. Corr’s goal was to avoid acid production by removing the free iron ions.

Once raised from the seabed, the ship was sprayed with cold water, which stopped it from drying out and prevented further microbial activity. The conservation team then sprayed the hull with different types of polyethylene glycol (PEG), a common polymer with a wide range of applications, to replace the water in the cellular structure of the wood and strengthen its outer layer.

Corr and her postdoctoral fellow Esther Rani Aluri, Ph.D., and Ph.D. candidate Enrique Sanchez at the University of Glasgow are devising a new family of tiny magnetic nanoparticles to aid in this process, in collaboration with Schofield and Rachel O’Reilly, Ph.D., at the University of Warwick. In their initial step, the team, led by Schofield, used synchrotron techniques to probe the nature of the sulfur species before turning the PEG sprays off, and then periodically as the ship dried. This was the first real-time experiment to closely examine  the evolution of oxidized sulfur and iron species. This accomplishment has informed efforts to design new targeted treatments for the removal of these harmful species from the Mary Rose wood.

The next step will be to use a nanocomposite based on core magnetic iron oxide nanoparticles that include agents on their surfaces that can remove the ions. The nanoparticles can be directly applied to the porous wood structure and guided to particular areas of the wood using external magnetic fields, a technique previously demonstrated for drug delivery. The nanocomposite will be encompassed in a heat-responsive polymer that protects the nanoparticles and provides a way to safely deliver them to and from the wood surface. A major advantage of this approach is that it allows for the complete removal of free iron and sulfate ions from the wood, and these nanocomposites can be tuned by tweaking their surfaces.

With this understanding, Corr notes, “Conservators will have, for the first time, a state-of-the-art quantitative and restorative method for the safe and rapid treatment of wooden artifacts. We plan to then transfer this technology to other materials recovered from the Mary Rose, such as textiles and leather.”

The researchers acknowledge funding from the Mary Rose Trust and the Leverhulme Trust.

There is a video about the Mary Rose produced by Agence France Presse (AFP) and published on Youtube in May 2013,

Here’s the text from AFP Mary Rose entry on Youtube,

The relics from the Mary Rose, the flagship of England’s navy when it sank in 1545 as a heartbroken king Henry VIII watched from the shore, have finally been reunited with the famous wreck in a new museum offering a view of life in Tudor times. Duration: 02:35

One more thing: Canadian shipwrecks

We don’t have a ‘Henry VIII’ story or ‘smart nano and shipwrecks’ story but we do have a federal agency devoted to underwater archaeology, Parks Canada Underwater Archaeology webpage,

Underwater archaeology deals with archaeological sites found below the surface of oceans, rivers, and lakes and on the foreshore. In addition to shipwrecks, underwater archaeologists study submerged aboriginal sites such as fish weirs and middens; remains of historic structures such as wharves, canal locks, and marine railways; sunken aircraft; and other submerged cultural heritage resources.

Underwater archaeology shares the same methodology and principles as archaeology carried out on land sites. All archaeology involves the careful study of artefacts, structures and features to reconstruct and explain the lives of people in the past. However, because it is carried out in a more challenging environment, underwater archaeological fieldwork is more complex than land archaeology.

Specialized techniques and equipment are required to work productively underwater. Staying warm during long dives is a constant concern, so underwater archaeologists often use masks that cover their entire faces, dry suits worn over layers of warm clothing, or in cases where the water is extremely cold, such as the excavation in Red Bay (Labrador), wet suits supplied with a flow of hot water. Underwater communication systems are used to talk to people on the surface or to other divers. Removing sediments covering underwater sites requires the controlled use of specially designed equipment such as suction airlifts and small dredges. Recording information underwater presents its own challenges. Special underwater paper is used for notes and drawings, while photo and video cameras are placed in waterproof housings.

Underwater archaeological fieldwork includes remote-sensing surveys using geophysical techniques, diving surveys to locate and map sites, site monitoring, and excavation. The success of an underwater archaeological project rests on accurate documentation of all aspects of the process. Meticulous mapping and recording are particularly essential when excavation is required, as artefacts and other physical evidence are permanently removed from their original contexts. Archaeologists aim to be able to reconstruct the entire site from the records they generate during fieldwork.

Underwater archeology with Marc-André Bernier

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There’s also a podcast interview with Marc-André Bernier where he discusses an important Canadian shipwreck, from the Library and Archives Canada, Underwater Canada: Investigating Shipwrecks webpage (podcast length 27:25), here’s the transcript for those who prefer reading,

Shipwrecks have stirred up interest in Canada’s maritime heritage for many decades. 2014 marks the 100th anniversary of the sinking of the Empress of Ireland, one of Canada’s worst maritime disasters.

In this episode, Marc-André Bernier, Chief of Parks Canada’s Underwater Archaeology Service, joins us to discuss shipwrecks, their importance in Canadian history, and how LAC plays an important role in researching, discovering and investigating them.

Podcast Transcript

Underwater Canada: Investigating Shipwrecks

Jessica Ouvrard: Welcome to “Discover Library and Archives Canada: Your History, Your Documentary Heritage.” I’m your host, Jessica Ouvrard. Join us as we showcase the treasures from our vaults; guide you through our many services; and introduce you to the people who acquire, safeguard and make known Canada’s documentary heritage.

Canada has a rich maritime history filled with many tragedies, from small boats [lost] in the Great Lakes, to the sinking of the Empress of Ireland in the St. Lawrence River, to Sir John Franklin’s doomed expeditions in the Arctic. The shipwrecks capture our imaginations and evoke images of tragedy, heroism, mystery and discovery. 2014 also marks the 100th anniversary of the sinking of the Empress of Ireland.

Marc-André Bernier, Chief of Parks Canada’s Underwater Archaeology Service, is joining us to discuss shipwrecks and their significance in Canada’s history, and LAC’s important role in the research, discovery and investigation of these shipwrecks.

Hello, Marc-André Bernier. Thank you for coming today.

Marc-André Bernier: My pleasure. Hello to you.

JO: For those who don’t know much about underwater archaeology, can you explain what it is and the risks and challenges that it presents?

MAB: I’ll start with the challenges rather than the risks, because there are obviously risks, but we try to minimize them. Diving is inherently risky. But I’ll start with the challenges because they are, to a certain extent, what characterize underwater archaeology.

We face a series of challenges that are more complicated, that make our work much more complicated than terrestrial archaeology. We work on water and underwater, and our working conditions are dictated by what happens outside, by nature. We can’t work every day on the water, especially if our work involves the sea or the ocean, for example. And when we work underwater, we have to deal with constraints in terms of time and sometimes visibility. That means that we have to be extremely well organized. Preparation is crucial. Logistics are crucial.

In terms of preparation, we need to properly prepare our research using archives and so on, but we also have to be prepared in terms of knowing what’s going on in the field. We need to know the environmental conditions and diving conditions, even when we can’t dive. Increasingly, the work involves heading into deeper areas that can only be reached by robots, by remotely operated equipment. So we have to be able to adapt.

We have to be very precise and very organized because sometimes we have only a few minutes to access a site that will tell us many historical secrets. So we have to come very well prepared.

And when we dive, we’re working in a foreign environment. We have to be good divers, yes, but we also have to have access to tools that will give us access to information. We have to take into account currents, darkness, and so on. The work is really very challenging. But with the rapid development of new technologies in recent years, we have access to more and more tools. We do basically the same work as archaeologists on land. However, the work is done in a completely different environment.

JO: A bit hostile in fact.

MAB: A bit hostile, but with sites, objects and information that are not accessible elsewhere. So there’s an opportunity to learn about history in a different way, and in some cases on a much larger scale.

JO: With all the maritime traffic in Canada, there must have been many accidents. Can you talk about them and give us an idea of the number?

MAB: People don’t realize that we’re a maritime country. We are a country that has evolved and developed around water. This was true even before the Europeans arrived. The First Nations often travelled by water. That travel increased or developed differently, if you will, when the Europeans arrived.

The St. Lawrence River, for example, and the Atlantic provinces were the point of entry and the route. We refer to different waterways, such as the Ottawa and Richelieu rivers. They constituted the route. So, there was heavy traffic, which meant many accidents. We’re talking about probably tens of thousands of shipwrecks if we include the Great Lakes and all the coasts of Canada. Since Canada has the longest coastline in the world, there is potential for shipwrecks. Only a small number of those shipwrecks have been found, but some are very significant and extremely impressive as well.

JO: Are there also many military ships, or is it more…?

MAB: That’s another thing that people don’t realize. There have been many military confrontations in Canadian waters, dating back to the New France era, or when Phips (Sir William Phips) arrived at Quebec City in 1690 and laid siege to the city. He arrived by ship and lost ships when he returned. During the Conquest, there were naval confrontations in Louisbourg, Nova Scotia; in Chaleur Bay; and even at Quebec City. Then, in the War of 1812, the Great Lakes were an extremely important maritime theatre of war in terms of naval battles. There are a number of examples in the Richelieu River.

Then we have the Second World War, with ships and German submarines. We all know the stories of the submarines that came inside the Gulf. So there are many military shipwrecks, from the New France era onward.

JO: What were the most significant shipwrecks in Canada? Have all the shipwrecks been found or…?

MAB: No. There are still shipwrecks that remain to be found. These days at Parks Canada, we’ve been looking for two of the shipwrecks that are considered among the most significant in the country: the HMS Erebus and the HMS Terror, Sir John Franklin’s ships lost in the Arctic. Franklin left England in 1845 to find the Northwest Passage, and he was never heard from again. Those are examples of significant shipwrecks that haven’t been found.

However, significance is always relative. A shipwreck may be very significant, especially if there is loss of life. It’s a tragic event that is deeply affecting. There are many shipwrecks that may not be seen as having national historic significance. However, at the local level, they are tragic stories that have very deep significance and that have profoundly affected an area.

That being said, there are ships that bear witness to memorable moments in the history of our country. Among the national historic sites of shipwrecks are, if we go back, the oldest shipwrecks: the Basque wrecks at Red Bay, Labrador, where whales were hunted in the 16th century. It’s even a UNESCO world heritage site. Then, from the New France era, there’s the Corossol from 1693 and the Phips wrecks from 1690. These are very significant shipwrecks.

Also of great significance are the Louisbourg shipwrecks, the battle site, the Battle of the Restigouche historic site, as well as shipwrecks such as the Hamilton and Scourge from the War of 1812. For all practical purposes, those shipwrecks are intact at the bottom of Lake Ontario. And the Franklin shipwrecks-even if they still haven’t been found-have been declared of national historic significance.

So there’s a wide range of shipwrecks that are significant, but there are thousands and thousands of shipwrecks that have significance. A shipwreck may also be of recreational significance. Some shipwrecks may be a little less historically significant, but for divers, they are exceptional sites for appreciating history and for having direct contact with history. That significance matters.

JO: Yes, they have a bit of a magical side.

MAB: They have a very magical side. When we dive shipwrecks, we travel through history. They give us direct access to our past.

JO: Yes. I imagine that finding a shipwreck is a bit like finding a needle in a haystack?

MAB: It can sometimes be a needle in a haystack, but often it’s by chance. Divers will sometimes stumble upon remains, and it leads to the discovery of a shipwreck. But usually, when we’re looking for a shipwreck, we have to start at the beginning and go to the source. We have to begin with the archives. We have to start by doing research, trying to find every small clue because searching in water over a large area is very difficult and complicated. We face logistical and environmental obstacles in our working conditions. It’s also expensive. We need to use ships and small boats.

There are different ways to find shipwrecks. At one extreme is a method that is technologically very simple. We dive and systematically search an area, if it’s not too deep. At the other extreme, we use the most sophisticated equipment. Today we have what we call robotic research vehicles. It is as sophisticated as launching the device, which is a bit like a self-guided torpedo. We launch it and recover it a few hours later. It carries out a sonar sweep of the bottom along a pre-programmed path. Between the two, we have a range of methods.

Basically, we have to properly define the boundaries of the area. It’s detective work. We have to try to recreate the events and define our search area, then use the proper equipment. The side-scan sonar gives us an image, and magnetometers detect metal. We have to decide which of the tools we’ll use. If we don’t do the research beforehand, we’ll lose a great deal of time.

JO: Have you used the LAC collections in your research, and what types of documents have you found?

MAB: Yes, as often as possible. We try to use the off-site archives, but it’s important to have access to the sources. Our research always starts with the archives. As for the types of documents, I mentioned the Basque documents that were collected through Library and Archives Canada. I’ve personally used colonial archives a lot. For the Corossol sinking in 1693, I remember looking at documents and correspondence that talked about the French recovery from the shipwreck the year after 1693, and the entire Phips epic.

At LAC, there’s a copy of the paintings of Creswell [Samuel Gurney Cresswell], who was an illustrator, painter, and also a lieutenant, in charge of doing illustrations during the HMS Investigator’s journey through the Arctic. So there’s a wide variety of documents, and sometimes we are surprised by the personal correspondence, which gives us details that official documents can’t provide.

JO: How do these documents help you in your research?

MAB: The archival records are always surprising. They help us in every respect. You have to see archaeology as detective work. Every detail is significant. It can be the change in topographical names on old maps that refer to events. There are many “Wreck Points” or “Pointe à la barque,” “Anse à la barque,” and so on. They refer to events. People named places after events. So we can always be surprised by bits of information that seem trivial at first.

It ranges from information on the sites and on the events that led to a shipwreck, to what happened after the sinking and what happened overall. What we want is not only to understand an event, but also to understand the event in the larger context of history, such as the history of navigation. Sometimes, the records provide that broader information.

It ranges from the research information to the analysis afterward: what we have, what we found, what it means and what it says about our history. That’s where the records offer limitless possibilities. We always have surprises. That’s why we enjoy coming to the archives, because we never know what we’ll discover.

JO: Yes, it’s always great to open a box.

MAB: It’s like Christmas. It’s like Christmas when we start delving into archival records, and it’s a sort of prelude to what happens in archaeology. When we reach a site, we’re always excited by what the site has to offer. But we have to be prepared to understand it. That’s why preparation using archives is extremely important to our work.

JO: In terms of LAC sources, do you often look at historical maps? Do you look at the different ones, because we have quite a large collection…

MAB: Quite exceptional, yes.

JO: … from the beginning until now?

MAB: Yes. They provide a lot of information, and we use them, like all sources, as much as possible. We look for different things on the maps. Obviously, we look for places that may show shipwreck locations. These maps may also show the navigation corridors or charts. The old charts show anchorages and routes. They help us recreate navigation habits, which helps us understand the navigation and maritime mindset of the era and gives us clues as to where the ships went and where they were lost.

These maps give us that type of information. They also give us information on the topography and the names of places that have changed over the years. Take the example of the Corossol in the Sept-Îles bay. One of the islands in that bay is called Corossol. For years, people looked for the French ship, the Corossol, near that island. However, Manowin Island was also called Corossol at that time and its name changed. So in the old maps, we traced the origin, and the ship lies much closer to that island. Those are some of the clues.

We also have magnificent maps. One in particular comes to mind. It was created in the 19th century on the Îles-de-la-Madeleine by an insurance company agent who made a wreck map of all the shipwrecks that he knew of. To us, that’s like candy. It’s one of the opportunities that maps provide. Maps are magnificent even if we don’t find clues. Just to admire them-they’re absolutely magnificent.

JO: From a historical point of view, why is it important to study shipwrecks?

MAB: Shipwrecks are in fact a microcosm. They represent a small world. During the time of the voyage, there was a world of its own inside the ship. That in itself is interesting. How did people live on board? What were they carrying? These are clues. The advantage of a shipwreck is that it’s like a Polaroid, a fixed image of a specific point in time. When we study a city such as Quebec City that has been continuously occupied, sometimes it’s difficult to see the separation between eras, or even between events. A shipwreck shows a specific time and specific place.

JO: And it’s frozen in time.

MAB: And it’s frozen in time. So here’s an image, in 1740, what did we have? Of course, we find objects made in other eras that were still in use in that time period. But it really gives us a fixed image, a capsule. We often have an image of a time capsule. It’s very useful, because it’s very rare to have these mini Pompeiis, and we have them underwater. It’s absolutely fascinating and interesting. It’s one of the contributions of underwater archaeology.

The other thing is that we don’t necessarily find the same type of material underwater as on land. The preservation conditions are completely different. On land, we find a great deal of metal. Iron stays fairly well preserved. But there’s not much organic material, unless the environment is extremely humid or extremely dry. Underwater, organic materials are very well preserved, especially if the sedimentation is fairly quick. I remember finding cartouches from 1690 that still had paper around them. So the preservation conditions are absolutely exceptional.

That’s why it’s important. The shipwrecks give us unique information that complements what we find on land, but they also offer something that can’t be found elsewhere.

JO: I imagine that there are preservation problems once it’s…

MAB: And that’s the other challenge.

JO: Yes, certainly.

MAB: If an object is brought up, we have to be ready to take action because it starts to degrade the moment we move it…

JO: It comes into contact with oxygen.

MAB: … Yes, but even when we move it, we expose it to a new corrosion, a new degradation. If we bring it to the surface right away, the process accelerates very quickly. We have to keep the object damp. We always have to be ready to take action. For example, if the water heats up too fast, micro-organisms may develop that accelerate the degradation. We then have to be ready to start preservation treatments, which can take years depending on the object. It’s an enormous responsibility and we have to be ready to handle it, if not, we destroy…

JO: … the heritage.

MAB: … what we are trying to save, and that’s to everyone’s detriment.

JO: Why do you think that people are so fascinated by archaeology, and more specifically by shipwrecks?

MAB: That’s also a paradox. We say that people aren’t interested in history. I am firmly convinced that people enjoy history and are interested in it. It must be well narrated, but people are interested in history. There’s already an interest in our past and in our links with the past. If people feel directly affected by the past, they’ll be fascinated by it. If we add on top of that the element of discovery, and archaeology is discovery, and all the myths surrounding artefact hunters…

JO: … treasure hunters.

MAB: … treasures, and so on. It’s an image that people have. Yes, we hunt treasure, but historical treasure. That image applies even more strongly to shipwrecks. There’s always that myth of the Spanish galleon filled with gold. Everyone thinks that all shipwrecks contain a treasure. That being said, there’s a fascination with discovery and with the past, and add on top of that the notion of the bottom of the sea: it’s the final frontier, where we can be surprised by what we discover. Since these discoveries are often remarkably well preserved, people are absolutely fascinated.

We grow up with stories of pirates, shipwrecks and lost ships. These are powerful images. A shipwreck is an image that captures the imagination. But a shipwreck, when we dive a shipwreck, we have direct contact with the past. People are fascinated by that.

JO: Are shipwreck sites accessible to divers?

MAB: Shipwreck sites are very accessible to divers. For us, it’s a basic principle. We want people to be able to visit these sites. Very rarely do we limit access to a site. We do, for example, in Louisbourg, Nova Scotia. The site is accessible, but with a guide. The site must be visited with a guide because the wrecks are unique and very fragile.

However, the basic principle is that, as I was saying, we should try to allow people to savour and absorb the spirit of the site. The best way is to visit the site. So there are sites that are accessible, and we try to make them accessible. We not only make them accessible, but we also promote them. We’re developing tools to provide information to people.

It’s also important to raise awareness. We have the opportunity and privilege to visit the sites. We have to ensure that our children and grandchildren have the same opportunity. So we have to protect and respect [the sites]. In that spirit, the sites have to be accessible because these experiences are absolutely incredible. With technology, we can now make them accessible not only to divers but also virtually, which is interesting and stimulating. Nowadays there are opportunities to make all these wonders available to as many people as possible, even if they don’t have the chance to dive.

JO: How long has Parks Canada been involved in underwater archaeology?

MAB: 2014 marks the 50th anniversary of the first dives at Fort Lennox in 1964 by Sean Gilmore and Walter Zacharchuk. That’s where it began. We’re going back there in August of this year, to the birthplace of underwater archaeology at Parks Canada.

We’re one of the oldest teams in the world, if we can say that. The first time an archaeologist dived a site was in 1960, so we were there basically at the beginning. Parks Canada joined the adventure very early on and it continues to be a part of it to this day. I believe that we’ve studied 225 sites across Canada, in the three oceans, the Great Lakes, rivers, truly across the entire country. We have a wealth of experience, and we’ll celebrate that this year by returning to Fort Lennox where it all began.

JO: Congratulations!

MAB: Thank you very much.

JO: 2014 marks the 100th anniversary of the sinking of the Empress of Ireland. What can you tell us about this maritime accident?

MAB: The story of the Empress begins on May 28, 1914. The Empress of Ireland left Quebec City for England with first, second and third class passengers on board. The Empress left Quebec in the late afternoon, with more than 1,400 passengers and crew on board. The ship headed down the St. Lawrence to Pointe au Père, a pilot station, because pilots were needed to navigate the St. Lawrence, given the reefs and hazards.

The pilot left the Empress at the Pointe au Père pilot station, and the ship resumed her journey. At the same time, the Storstad, a cargo ship, was heading in the opposite direction. In the fog, the two ships collided. The Storstad rammed the Empress of Ireland, creating a hole that immediately filled with water.

At that moment, it was after 1:30 a.m., so almost 2:00 a.m. It was night and foggy. The ship sank within 14 minutes, with a loss of 1,012 lives. Over 400 people survived, but over 1,000 people [died]. Many survivors were pulled from the water either by the ship that collided with the Empress or by other ships that were immediately dispatched.

JO: 14 minutes…

MAB: … In 14 minutes, the ship sank. The water rushed in and the ship sank extremely fast, leaving very little opportunity for people, especially those deeper inside the ship, to save themselves.

JO: So a disaster.

MAB: The greatest maritime tragedy in the history of the country.

JO: What’s your most unforgettable experience at an underwater archaeology site?

MAB :I’ve been doing this job for 24 years now, and I can tell you that I have had extraordinary experiences! There are two that stand out.

One was a Second World War plane in Longue-Pointe-de-Mingan that sank after takeoff. Five of the nine crew members drowned in the plane. In 2009, the plane was found intact at a depth of 40 metres. We knew that five of the crew members were still inside. What was absolutely fascinating, apart from the sense of contact and the very touching story, was that we had the opportunity, chance and privilege to have people who were on the beach when the event occurred, who saw the accident and who saw the soldiers board right beforehand. They told us how it happened and they are a direct link. They are part of the history and they experienced that history.

That was an absolutely incredible human experience. We worked with the American forces to recover the remains of the soldiers. Seeing people who had witnessed the event and who could participate 70 years later was a very powerful moment. Diving the wreck of that plane was truly a journey through time.

The other experience was with the HMS Investigator in the Arctic. That’s the ship that was credited with discovering the Northwest Passage. Actually, the crew found it, since the ship remained trapped in the ice and the crew continued on foot and were saved by another ship. The ship is practically intact up to the upper deck in ten metres of water. When you go down there, the area is completely isolated. The crew spent two winters there. On land we can see the remains of the equipment that they left on the ground. Three graves are also visible. So we can absorb the fact that they were in this environment, which was completely hostile, for two years, with the hope of being rescued.

And the ship: we then dive this amazing exploration machine that’s still upright, with its iron-clad prow to break the ice. It’s an icebreaker from the 1850s. We dive on the deck, with the debris left by the ice, the pieces of the ship completely sheared off by the ice. But underneath that is a complete ship, and on the inside, everything that the people left on board.

I often say that it’s like a time travel machine. We are transported and we can absorb the spirit of the site. That’s what I believe is important, and what we at Parks [Canada] try to impart, the spirit of the site. There was a historic moment, but it occurred at a site. That site must be seen and experienced for maximum appreciation. That’s part of the essence of the historic event and the site. On that site, we truly felt it.

JO: Thank you very much for coming to speak with us today. We greatly appreciate your knowledge of underwater Canada. Thank you.

MAB: Thank you very much.

JO: To learn more about shipwrecks, visit our website Shipwreck Investigations at lac-bac.gc.ca/sos/shipwrecks or read our articles on shipwrecks on thediscoverblog.com [I found other subjects but not shipwrecks in my admittedly brief search of the blog].

Thank you for joining us. I’m your host, Jessica Ouvrard, and you’ve been listening to “Discover Library and Archives Canada-where Canadian history, literature and culture await you.” A special thanks to our guest today, Marc-André Bernier.

A couple of comments. (1) It seems that neither Mr. Bernier nor his team have ever dived on the West Coast or west of Ottawa for that matter. (2) Given Bernier’s comments about oxygen and the degradation of artefacts once exposed to the air, I imagine there’s a fair of amount of excitement and interest in Corr’s work on ‘smart nanotech’ for shipwrecks.

Art masterpieces are turning into soap

This piece of research has made a winding trek through the online science world. First it was featured in an April 20, 2017 American Chemical Society news release on EurekAlert,

A good art dealer can really clean up in today’s market, but not when some weird chemistry wreaks havoc on masterpieces. Art conservators started to notice microscopic pockmarks forming on the surfaces of treasured oil paintings that cause the images to look hazy. It turns out the marks are eruptions of paint caused, weirdly, by soap that forms via chemical reactions. Since you have no time to watch paint dry, we explain how paintings from Rembrandts to O’Keefes are threatened by their own compositions — and we don’t mean the imagery.

Here’s the video,

Interestingly, this seems to be based on a May 23, 2016 article by Sarah Everts for Chemical and Engineering News (an American Society publication) Note: Links have been removed,

When conservator Petria Noble first peered at Rembrandt’s “Anatomy Lesson of Dr. Nicolaes Tulp” under a microscope back in 1996, she was surprised to find pockmarks across the nearly 400-year-old painting’s surface.

Each tiny crater was just a few hundred micrometers in diameter, no wider than the period at the end of this sentence. The painting’s surface was entirely riddled with these curious structures, giving it “a dull, rather hazy, gritty surface,” Noble says.

A structure of lead nonanoate.

The crystal structures of metal soaps vary: Shown here is lead nonanoate, based on a structure solved by Cecil Dybowski at the University of Delaware and colleagues at the Metropolitan Museum of Art. Dashed lines are nearest oxygen neighbors.

This concerned Noble, who was tasked with cleaning the masterpiece with her then-colleague Jørgen Wadum at the Mauritshuis museum, the painting’s home in The Hague.

When Noble called physicist Jaap Boon, then at the Foundation for Fundamental Research on Matter in Amsterdam, to help figure out what was going on, the researchers unsuspectingly embarked on an investigation that would transform the art world’s understanding of aging paint.

More recently this ‘metal soaps in paintings’ story has made its way into a May 16, 2017 news item on phys.org,

An oil painting is not a permanent and unchangeable object, but undergoes a very slow change in the outer and inner structure. Metal soap formation is of great importance. Joen Hermans has managed to recreate the molecular structure of old oil paints: a big step towards better preservation of works of art. He graduated cum laude on Tuesday 9 May [2017] at the University of Amsterdam with NWO funding from the Science4Arts program.

A May 15, 2017 Netherlands Organization for Scientific Research (NWO) press release, which originated the phys.org news item, provides more information about Hermans’ work (albeit some of this is repetitive),

Johannes Vermeer, View of Delft, c. 1660 - 1661 (Mauritshuis, The Hague)Johannes Vermeer, View of Delft, c. 1660 – 1661 (Mauritshuis, The Hague)

Paint can fade, varnish can discolour and paintings can collect dust and dirt. Joen Hermans has examined the chemical processes behind ageing processes in paints. ‘While restorers do their best to repair any damages that have occurred, the fact remains that at present we do not know enough about the molecular structure of ageing oil paint and the chemical processes they undergo’, says Hermans. ‘This makes it difficult to predict with confidence how paints will react to restoration treatments or to changes in a painting’s environment.’

‘Sand grains’ In the red tiles of 'View of Delft' by Johannes Vermeer shows 'lead soap spheres' (Annelies van Loon, UvA/Mauritshuis)‘Sand grains’ In the red tiles of ‘View of Delft’ by Johannes Vermeer shows ‘lead soap spheres’ (Annelies van Loon, UvA/Mauritshuis)

Visible to the naked eye

Hermans explains that in its simplest form, oil paint is a mixture of pigment and drying oil, which forms the binding element. Colour pigments are often metal salts. ‘When the pigment and the drying oil are combined, an incredibly complicated chemical process begins’, says Hermans, ‘which continues for centuries’. The fatty acids in the oil form a polymer network when exposed to oxygen in the air. Meanwhile, metal ions react with the oil on the surface of the grains of pigment.

‘A common problem when conserving oil paintings is the formation of what are known as metal soaps’, Hermans continues. These are compounds of metal ions and fatty acids. The formation of metal soaps is linked to various ways in which paint deteriorates, as when it becomes increasingly brittle, transparent or forms a crust on the paint surface. Hermans: ‘You can see clumps of metal soap with the naked eye on some paintings, like Rembrandt’s Anatomy Lesson of Dr Nicolaes Tulp or Vermeer’s View of Delft’. Around 70 per cent of all oil paintings show signs of metal soap formation.’

Conserving valuable paintings

Hermans has studied in detail how metal soaps form. He began by defining the structure of metal soaps. One of the things he discovered was that the process that causes metal ions to move in the painting is crucial to the speed at which the painting ages. Hermans also managed to recreate the molecular structure of old oil paints, making it possible to simulate and study the behaviour of old paints without actually having to remove samples from Rembrandt’s Night Watch. Hermans hopes this knowledge will contribute towards a solid foundation for the conservation of valuable works of art.

I imagine this will make anyone who owns an oil painting or appreciates paintings in general pause for thought and the inclination to utter a short prayer for conservators to find a solution.

Sniffing for art conservation

The American Chemical Society (ACS) has produced a video titled, “How that ‘old book smell’ could save priceless artifacts” according to their Sept. 6, 2016 news release on EurekAlert,

Odor-detecting devices like Breathalyzers have been used for years to determine blood-alcohol levels in drunk drivers. Now, researchers are using a similar method to sniff out the rate of decay in historic art and artifacts. By tracking the chemicals in “old book smell” and similar odors, conservators can react quickly to preserve priceless art and artifacts at the first signs of decay. In this Speaking of Chemistry, Sarah Everts explains how cultural-heritage science uses the chemistry of odors to save books, vintage jewelry and even early Legos. …

Here’s the video,

Heritage Smells, the UK project mentioned in the video, is now completed but it was hosted by the University of Strathclyde and more project information can be found here.

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,)

Protecting Disney’s art with an artificial nose

Curators and conservators are acutely aware of how fragile artworks (see my Jan. 10, 2013 posting about a show where curators watched helplessly as daguerreotypes deteriorated) can be so this new technology from Disney is likely to excite a lot of interest. From a March 14, 2016 news item on phys.org,

Original drawings and sketches from Walt Disney Animation Studio’s more than 90-year history—from Steamboat Willie through Frozen—traveled internationally for the first time this summer. This gave conservators the rare opportunity to monitor the artwork with a new state-of-the-art sensor. A team of researchers report today that they developed and used a super-sensitive artificial “nose,” customized specifically to detect pollutants before they could irreversibly damage the artwork.

Here’s a sample of the art work,

Caption: To protect works of art, including this image of Disney's Steamboat Willie, scientists developed an optoelectronic "nose" to sniff out potentially damaging compounds in pollution. Credit: Steamboat Willie, 1928 Animation cel and background © Disney Enterprises, Inc. Courtesy of Walt Disney Animation Research Library

Caption: To protect works of art, including this image of Disney’s Steamboat Willie, scientists developed an optoelectronic “nose” to sniff out potentially damaging compounds in pollution. Credit: Steamboat Willie, 1928 Animation cel and background © Disney Enterprises, Inc. Courtesy of Walt Disney Animation Research Library

A March 14, 2016 American Chemical Society (ACS) news release (also on EurekAlert), provides more detail,

The researchers report on their preservation efforts at the 251st National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through Thursday. It features more than 12,500 presentations on a wide range of science topics.

“Many pollutants that are problematic for human beings are also problematic for works of art,” says Kenneth Suslick, Ph.D. For example, pollutants can spur oxidative damage and acid degradation that, in prints or canvases, lead to color changes or decomposition. “The ability to monitor how much pollution a drawing or painting is exposed to is an important element of art preservation,” he says.

However, works of art are susceptible to damage at far lower pollutant levels than what’s considered acceptable for humans. “The high sensitivity of artists’ materials makes a lot of sense for two reasons,” explains Suslick, who is at the University of Illinois at Urbana-Champaign. “Human beings are capable of healing, which, of course, works of art cannot do. Moreover, human beings have finite lifetimes, whereas ideally works of art should last for future generations.”

To protect valuable works of art from these effects, conservators enclose vulnerable pieces in sealed display cases. But even then, some artists’ materials may “exhale” reactive compounds that accumulate in the cases and damage the art. To counter the accumulation of pollutants, conservators often hide sorbent materials inside display cases that scrub potentially damaging compounds from the enclosed environment. But it is difficult to know precisely when to replace the sorbents.

Suslick, a self-proclaimed “museum hound,” figured he might have an answer. He had already invented an optoelectronic nose — an array of dyes that change color when exposed to various compounds. But it is used largely for biomedical purposes, and it can’t sniff out the low concentrations of pollutants that damage works of art. To redesign the nose with the aim of protecting artwork, he approached scientists at the Getty Conservation Institute (GCI), a private non-profit institution in Los Angeles that works internationally to advance art conservation practice. He proposed that his team devise a sensor several hundred times more sensitive than existing devices used for cultural heritage research. The collaboration took off, and the scientists built a keener nose.

At the time, GCI was involved in a research project with the Walt Disney Animation Research Library to investigate the impact of storage environment on their animation cels, which are transparent sheets that artists drew or painted on before computer animation was developed. Such research ultimately could help extend the life of this important collection. The new sensors would monitor levels of acetic acid and other compounds that emanate from these sheets.

Before the exhibit, “Drawn from Life: The Art of Disney Animation Studios,” hit the road on tour, Suslick recommended placing the sensors in discrete places to monitor the pollution levels both inside and outside of the sealed and framed artworks. If the sensors indicated pollution levels inside the sealed frames were rising, conservators traveling with the Disney exhibit would know to replace the sorbents. An initial analysis of sensor data showed that the sorbents were effective. Suslick says he expects to continue expanding the sensors’ applications in the field of cultural heritage.

Collaborators in the project include Maria LaGasse, a graduate student in Suslick’s lab; Kristen McCormick, art exhibitions and conservation manager at the Walt Disney Animation Research Library; Herant Khanjian, assistant scientist; and Michael Schilling, senior scientist at the Getty Conservation Institute.

I was able to find one museum exhibiting “Drawn from Life: The Art of Disney Animation Studios”; it was the Museum of China which hosted the show from June 30 – August 18, 2015. There are pictures of the exhibit at the Museum of China posted by Leon Ingram here on Behance.

NANOART Research Tool offers affordable paint analysis

There’s some encouraging news for art conservators and authenticators, an affordable nanotech-based kit for greater accuracy analyzing ancient (or old)  paint is one step closer according to a Jan. 11, 2016 notice on CORDIS,

Developed through the EU-funded NANOART project, the new testing kit has already been applied to identify binders such as collagen and ovalbumin in ancient paint, not only in model samples painted in the lab but also in real samples collected from works of art.

‘Once fully completed, our new tool will be made available to conservation scientists from around the world at an affordable cost (an assay can cost around EUR 0.5 per target), which will facilitate greater knowledge about historical works of art and help international museums, restoration art studios and laboratories to plan the best conservation and preventive strategies,’ explains NANOART project coordinator Dr Jesus de la Fuente from the CSIC/University of Zaragoza, Spain.

In addition, the sensitiveness of the project’s new nanotechnology-based methods means that smaller samples are required to be taken from the artwork for analysis. This in itself will help to better preserve our cultural heritage.

In order to characterise ancient paints, experts have often relied on conventional molecular biology methodologies that were developed decades ago. The concept behind the NANOART project was that these techniques could be substituted by more sensitive, inexpensive and faster techniques that take advantage of emerging nanotechnologies.

Furthermore, conventional methods – apart from being expensive – are also only available at a few laboratories, and require specialised personnel and equipment. A key objective of the NANOART project has been to address the cost issue by applying techniques developed for clinical diagnosis. In this way, the project is also highly original as it aims to take latest developments in clinical medicine and apply them to the conservation and preservation of cultural heritage.

‘The innovative nature of the project is also denoted by the fact that there is currently no method or kit available that can be easily used at point-of-care to analyse paints without requiring expensive equipment and extensive training,’ says Ana Claro, research fellow from the INA/University of Zaragoza. ‘With the NANOART kit, the final user will be able to conduct an affordable analysis (in some cases at the cost of only a few euros) by simply following the instructions. Within a four-hour period, the results will be available.’

The potential opportunities opened up by the new analytical nanotechnology are huge. For example, developed in parallel with the NANOART kit, a spin-off company called NanoImmunotech has been launched in order to develop devices to detect bacterial infection in meat using the same technology as used in NANOART.

‘This opens our technology to other applications far from cultural heritage applications,’ says de la Fuente. ‘However, we would like to continue further developing novel uses of NANOART technology for other applications in cultural heritage, and our next step will be to look for funding to develop an even more user friendly device.’

This announcement comes just as the NANOART project is scheduled to be completed (Jan. 31, 2016) according to its webpage on CORDIS.

For those with Spanish language skills, there’s this Jan. 11, 2016 news item on the Catalunya Vanguardista website (I believe the English language version above is a machine translation with this being the original text),

Nanotecnología para analizar pinturas históricas de forma barata y precisa

Empleando nanotecnologías, se ha creado un equipo de diagnóstico clínico destinado a analizar capas de pintura antiguas que podría ahorrar costes a los profesionales de la conservación y permitirles alcanzar mayor precisión.

Cordis / El nuevo equipo de ensayo, desarrollado mediante el proyecto financiado con fondos europeos NANOART, ya se ha empleado en la identificación de aglutinantes como el colágeno y la ovoalbúmina en pinturas históricas. Además, los resultados se han obtenido tanto con muestras pintadas en el laboratorio como con otras extraídas de obras de arte.

«Una vez completemos su desarrollo, nuestra herramienta quedará a disposición de científicos de todo el mundo dedicados a la conservación por un módico precio (cada ensayo costará cerca de medio euro por objetivo). De este modo se obtendrá un conocimiento más profundo sobre las obras de arte históricas y tanto museos como talleres de restauración y laboratorios podrán plantear las estrategias de conservación y prevención idóneas», explicó el coordinador del proyecto, el Dr. Jesús de la Fuente del Instituto de Ciencia de los Materiales —centro mixto dependiente del CSIC y la Universidad de Zaragoza (España)—.Además, la sensibilidad ofrecida por los métodos nanotecnológicos propuestos por el proyecto permite extraer muestras de menor tamaño de las obras de arte, lo cual contribuirá a conservar mejor el patrimonio cultural.Para caracterizar pinturas antiguas, hasta ahora los expertos solían emplear metodologías convencionales de la biología molecular desarrolladas hace decenios. La propuesta del proyecto NANOART pasa por sustituir estas técnicas por otras más sensibles, baratas y rápidas que se valen de las nanotecnologías emergentes.

Es más, los métodos convencionales, además de resultar caros, sólo están a disposición de unos pocos laboratorios que cuentan con equipos y personal especializados. NANOART se propuso sobre todo abaratar los costes mediante el empleo de técnicas de diagnóstico del ámbito clínico. La originalidad de este planteamiento es notoria, pues aprovecha los últimos progresos logrados en medicina clínica para aplicarlos a la conservación y la protección del patrimonio cultural.

«La naturaleza innovadora del proyecto también obedece a la carencia hoy en día de un método o equipo que pueda emplearse con facilidad in situ para analizar pinturas sin necesidad de equipos caros ni formación exhaustiva», afirmó Ana Claro, investigadora del INA de la Universidad de Zaragoza. «Gracias al equipo de NANOART, el usuario final podrá ejecutar ensayos asequibles, en algunos casos por valor de tan sólo unos pocos euros, siguiendo las instrucciones proporcionadas. Los resultados estarán disponibles en cuatro horas».

Las oportunidades que ofrece la nueva nanotecnología analítica son enormes. Por ejemplo, la empresa derivada NanoImmunotech se ha puesto en marcha en paralelo al desarrollo del equipo de NANOART para que cree servicios con los que detectar infecciones bacterianas en la carne mediante los mismos métodos empleados por el proyecto en el ámbito del arte.

«De esta forma se amplían las aplicaciones de la tecnología a otros campos muy alejados del patrimonio cultural», afirmó de la Fuente. «No obstante, seguiremos indagando en nuevos usos de la tecnología de NANOART relacionados con el patrimonio cultural y procederemos ya a buscar fuentes de financiación que nos permitan crear un dispositivo aún más fácil de usar».

I expect the folks at the Canadian Conservation Institute (CCI) and other such insitutions are keeping a close eye on developments of this nature. The institute was mentioned here in the context of a series I wrote on attempts to authenticate a painting, Autumn Harbour, as a Lawren Harris (one of Canada’s Group of Seven painters). My July 14, 2014 post was devoted to a response from Marie-Claude Corbeil to a query about scientific investigation of visual art,

… [the response],

The Canadian Conservation Institute (CCI) has been conducting research into the materials and techniques of Canadian artists (mainly 20th-century artists) since the early 1990s. Databases were created for each artists. At the moment CCI has no such database on Harris.

The CCI is the only institution in Canada carrying out this kind of research. I would add that European conservation institutes or laboratories have a long tradition of conducting this type of research focusing mainly on European art, basically because many were created long before North-American conservation institutes or laboratories were established.

I was quite fascinated by the whole thing and wrote a four-part series about Autumn Harbour, Lawren Harris, and much more, as well as, the July 14, 2014 post, which has links to the Autumn Harbour series along with the response from the CCI and links to articles recommended by Corbeil.

2015 daguerreotype exhibit follows problematic 2005 show

In 2005, curators had a horrifying experience when historical images (daguerreotypes) were deteriorating as the 150-year old images were being displayed in an exhibit titled “Young America.” Some 25 of the photographs were affected, five of them sustaining critical damage. The debacle occasioned a research project involving conservators, physicists, and nanotechnology (see my Jan. 10, 2013 posting for more about the 2005 exhibit and resulting research project).

A new daguerreotype exhibit currently taking place showcases the results of that research according to a Nov. 13, 2015 University of Rochester news release,

In 1839, Louis-Jacques-Mandé Daguerre unveiled one of the world’s first successful photographic mediums: the daguerreotype. The process transformed the human experience by providing a means to capture light and record people, places, and events. The University of Rochester is leading groundbreaking nanotechnology research that explores the extraordinary qualities of this photographic process. A new exhibition in Rush Rhees Library showcases the results of this research, while bridging the gap between the sciences and the humanities. …

… From 2010-2014, a National Science Foundation grant supported nanotechnology research conducted by two University of Rochester scientists—Nicholas Bigelow, Lee A. DuBridge Professor of Physics, and Ralph Wiegandt, visiting research scientist and conservator—who explored how environment impacts the survival of these unique, non-reproducible images. In addition to conservation science and cultural research, Bigelow and Wiegandt are also investigating ways in which the chemical and physical processes used to create daguerreotypes can influence modern nanofabrication and nanotechnology.

“The daguerreotype should be considered one of humankind’s most disruptive technological advances,” Bigelow and Wiegandt said. “Not only was it the first successful imaging medium, it was also the first truly engineered nanotechnology. The daguerreotype was a prescient catalyst to the ensuing cascade of discoveries in physics and chemistry over the latter half of the 19th century and into the 20th.”

Blending the past with the future, the exhibition displays the first known daguerreotype of a Rochester graduating class (1853) alongside a 2015 daguerreotype of current University President Joel Seligman, created by Rochester daguerreotypist Irving Pobboravsky.

Both Bigelow and Wiegandt are mentioned in the 2013 posting describing the research project’s inception.

For anyone who’s in the area of New York state where the University of Rochester is located, the exhibit will run until February 29, 2016 in the Friedlander Lobby of Rush Rhees Library.  Plus, there’s this from the news release,

A special presentation about the scientific advances surrounding the daguerreotype and their relationship to cultural preservation will be led by Bigelow, Wiegandt, and Jim Kuhn, assistant dean for Special Collections and Preservation, on December 14 from 7-9 p.m. in the Hawkins-Carlson Room of Rush Rhees Library. For more information visit: http://www.library.rochester.edu/event/daguerreotype-exhibition or call (585).

There’s no indication that the special presentation will be livestreamed or recorded and made available at a later date.

Nanotechnology and drones for London’s (UK) Old Royal Naval College (ORNC)

It’s an art conservation project where nanotechnology and drones will be employed to help preserve the Old Royal Naval College’s (ORNC) Painted Hall. From an April 12, 2015 news item on Nanotechnology Now,

Plans for a major conservation project to restore the Painted Hall at the Old Royal Naval College (ORNC) in Greenwich, UK, will be announced in the US at an event on 14th May 2015 hosted by the British Consulate General in New York.

The ORNC, Sir Christopher Wren’s twin-domed riverside masterpiece stands on the site of the Greenwich Palace, Henry VIII’s birthplace and favorite royal residence. It is one of the most important ensembles in European baroque architecture.

Following a £2.77 million pledge in November 2014 from the Heritage Lottery Fund, the ORNC are embarking on the second stage of its plans to restore the Painted Hall to its former glory. A further £4 million is required to achieve the full scale of this landmark project.

Cutting-edge technologies are being applied for this conservation project, including drones and nanotechnology-enabled materials.

About the Old Royal Naval College

The Old Royal Naval College (ORNC) in Greenwich was established as the Royal Hospital for Seamen by King William III and Queen Mary II in 1694.

Designed by Sir Christopher Wren, it is one of the most important ensembles in European baroque architecture. From 1705, the Royal Hospital provided modest, wood-lined cabins as accommodation for retired sailors, housing as many as 2,700 residents at its peak in 1814. The last naval pensioners left in 1869, when the site became home to the Royal Naval College, an officers’ training academy, until 1997. When the Navy left, an independent charity was established to conserve the site for present and future generations, and create enjoyment, learning and unique cultural experiences for everyone.

Today this historic landmark is open to the public and is the home of three unique and free to visit attractions; the Painted Hall, the Chapel, and the Discover Greenwich visitor centre.

The Painted Hall is the greatest piece of decorative painting in England and has been described as ‘the Sistine Chapel of the UK’. The walls and ceilings were painted by Sir James Thornhill between 1708 and 1727.

The Chapel of St Peter and St Paul is a neo-classical masterpiece by James ‘Athenian’ Stuart and William Newton. Featuring a Samuel Green organ and an altarpiece painted by Benjamin West, it is one of the finest eighteenth century interiors in existence.

Here’s the Painted Hall and Chapel,

 

 Gryffindor derivative work: Fpo (talk) - Royal_Naval_College_Greenwich_001.JPG Royal_Naval_College_Greenwich_002.JPG  Creative Commons Attribution-Share Alike 3.0

Gryffindor derivative work: Fpo (talk) – Royal_Naval_College_Greenwich_001.JPG Royal_Naval_College_Greenwich_002.JPG Creative Commons Attribution-Share Alike 3.0

You can find out more about the ORNC here.

Masterpieces seen in a new light

Caption: This image shows: After Raphael 1483 - 1520 probably before 1600 Oil on wood 87 x 61.3 cm Wynn Ellis Bequest, 1876 Credit: © National Gallery, London

Caption: This image shows: After Raphael 1483 – 1520
probably before 1600
Oil on wood
87 x 61.3 cm
Wynn Ellis Bequest, 1876
Credit: © National Gallery, London

An April 13, 2015 Optical Society news release (also on EurekAlert) describes a new technique for ‘seeing’ below the surface of a painting without taking samples,

A painting hanging on the wall in an art gallery tells one story. What lies beneath its surface may tell quite another.

Often in a Rembrandt, a Vermeer, a Leonardo, a Van Eyck, or any other great masterpiece of western art, the layers of paint are covered with varnish, sometimes several coats applied at different times over their history. The varnish was originally applied to protect the paint underneath and make the colors appear more vivid, but over the centuries it can degrade. Conservators carefully clean off the old varnish and replace it with new, but to do this safely it is useful to understand the materials and structure of the painting beneath the surface. Conservation scientists can glean this information by analyzing the hidden layers of paint and varnish.

Now, researchers from Nottingham Trent University’s School of Science and Technology have partnered with the National Gallery in London to develop an instrument capable of non-invasively capturing subsurface details from artwork at a high resolution. Their setup, published in an Optics Express paper, will allow conservators and conservation scientists to more effectively peek beneath the surface of paintings and artifacts to learn not only how the artist built up the original composition, but also what coatings have been applied to it over the years.

Traditionally, analyzing the layers of a painting requires taking a very small physical sample — usually around a quarter of a millimeter across — to view under a microscope. The technique provides a cross-section of the painting’s layers, which can be imaged at high resolution and analyzed to gain detailed information on the chemical composition of the paint, but does involve removing some original paint, even if only a very tiny amount. When studying valuable masterpieces, conservation scientists must therefore sample very selectively from already-damaged areas, often only taking a few minute samples from a large canvas.

More recently, researchers have begun to use non-invasive imaging techniques to study paintings and other historical artifacts. For example, Optical Coherence Tomography (OCT) was originally developed for medical imaging but has also been applied to art conservation. Because it uses a beam of light to scan the intact painting without removing physical samples, OCT allows researchers to analyze the painting more extensively. However, the spatial resolution of commercially-available OCT setups is not high enough to fully map the fine layers of paint and varnish.

The Nottingham Trent University researchers gave OCT an upgrade. “We’re trying to see how far we can go with non-invasive techniques. We wanted to reach the kind of resolution that conventional destructive techniques have reached,” explained Haida Liang, who led the project.

In OCT, a beam of light is split: half is directed towards the sample, and the other half is sent to a reference mirror. The light scatters off both of these surfaces. By measuring the combined signal, which effectively compares the returned light from the sample versus the reference, the apparatus can determine how far into the sample the light penetrated. By repeating this procedure many times across an area, researchers can build up a cross-sectional map of the painting.

Liang and her colleagues used a broadband laser-like light source — a concentrated beam of light containing a wide range of frequencies. The wider frequency range allows for more precise data collection, but such light sources were not commercially available until recently.

Along with a few other modifications, the addition of the broadband light source enabled the apparatus to scan the painting at a higher resolution. When tested on a late 16th-century copy of a Raphael painting, housed at the National Gallery in London, it performed as well as traditional invasive imaging techniques.

“We are able to not only match the resolution but also to see some of the layer structures with better contrast. That’s because OCT is particularly sensitive to changes in refractive index,” said Liang. In some places, the ultra-high resolution OCT setup identified varnish layers that were almost indistinguishable from each other under the microscope.

Eventually, the researchers plan to make their instrument available to other art institutions. It could also be useful for analyzing historical manuscripts, which cannot be physically sampled in the same way that paintings can.

In a parallel paper recently published in Optics Express, the researchers also improved the depth into the painting that their apparatus can scan. The two goals are somewhat at odds: using a longer wavelength light source could enhance the penetration depth, but shorter wavelength light (as used in their current setup) provides the best resolution.

“The next challenge is perhaps to be able to do that in one instrument, as well as to extract chemical information from different layers,” said Liang.

Here are links to and citations for the two recent papers published by Liang and her team,

Ultra-high resolution Fourier domain optical coherence tomography for old master paintings by C. S. Cheung, M. Spring, and H. Liang. Optics Express, Vol. 23, Issue 8, pp. 10145-10157 (2015) http://dx.doi.org/10.1364/OE.23.010145

High resolution Fourier domain optical coherence tomography in the 2 μm wavelength range using a broadband supercontinuum source by C. S. Cheung, J. M. O. Daniel, M. Tokurakawa, W. A. Clarkson, and H. Liang. Optics Express, Vol. 23, Issue 3, pp. 1992-2001 (2015) http://dx.doi.org/10.1364/OE.23.001992

Both papers are open access.