DOE News
    Doe Science news source
    The DOE Science News Source is a Newswise initiative to promote research news from the Office of Science of the DOE to the public and news media.
    • 2019-08-29 11:00:38
    • Article ID: 718198

    The Chemistry of Art: Scientists Explore Aged Paint in Microscopic Detail to Inform Preservation Efforts

    Study involving X-ray imaging at Berkeley Lab provides clues to how artwork composed of oil paints can deteriorate over time

    • Credit: iStock/piranka, Lawrence Berkeley National Laboratory

      Photo illustration of the periodic table of elements on an art canvas.

    • Credit: National Gallery of Art

      This image shows a canvas with paint samples that are studied in detail to learn about chemical changes as the samples age.

    • Credit: National Institute of Standards and Technology, Lawrence Berkeley National Laboratory

      An X-ray microtomography scan of a paint sample (left) shows a random distribution of components in a paint sample, and a zoomed-in view by a technique known as photothermal induced resonance (right) reveals that zinc carboxylates, known as soaps, are not evenly distributed but are intermixed with aluminum stearate (yellow). One type of zinc soap, called zinc stearate, is also shown to form in clusters of nanoparticles (red) near the aluminum stearate cluster. The scale bars are in microns, or millionths of a meter.

    Watching paint dry may seem like a boring hobby, but understanding what happens after the paint dries can be key in preserving precious works of art. 

    The formation of metal soaps in artwork composed with oil paints can cause “art acne” – including pimpling and more severe deterioration – which poses a pressing challenge for art conservation around the globe.

    It is affecting the works of Georgia O’Keefe, Vincent Van Gogh, Francisco de Goya, and Jackson Pollock, among many others, and researchers haven’t yet found a good solution to stop its effects.

    To learn more about the chemical processes involved in aging oil paints in microscopic and nanoscale detail, an international team led by researchers at the National Gallery of Art and the National Institute of Standards and Technology (NIST) conducted a range of studies that included 3D X-ray imaging of a paint sample at the Advanced Light Source (ALS), a synchrotron at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).

    “An estimated 70 percent of oil paintings might already have or will have these metal-soap problems,” said Xiao Ma, Charles E. Culpeper Fellow at the National Gallery of Art who was the lead author of the team’s study, published in the journal Angewandte Chemie International Edition.

    “In our collections we see soaps in the paintings – I would say it’s not uncommon,” he noted. “They might not already show at the surface, but exist at the ‘ground,’ or priming layers. 

    The same damaging chemistry, which previous studies have traced to the mixing of fatty acids with metal ions present in paint pigments including lead, zinc, copper, cadmium, and manganese, has been found occurring in some organic coatings, too, such as those used for bronze sculptures and in industry, Ma noted.

    The latest study focused on one paint called “Soft Titanium White” that was painted on a canvas in 1995 by a paint manufacturer. In addition to titanium dioxide (TiO2), it contains zinc oxide (ZnO), which is known to form soaps. Paints like it have been in use since around 1930, Ma said. The aged sample hasn’t been treated in any way and has remained in a controlled environment.

    The study found that clusters of a compound called aluminum stearate are distributed randomly in the paint, and that zinc carboxylates, known as soaps, are intermixed within them. The high spatial resolution analysis showed that one sort of zinc soap, zinc stearate, aggregates in proximity to these clusters.

    And while the paint sample didn’t yet show physical deterioration, researchers found signs that paint fragmentation and chipping (spalling) could eventually occur if zinc soaps become more concentrated and localized within the paint over time.

    “We’re trying to get a handle on the very beginning processes to understand where the soaps might be forming and where they might be moving – if they’re moving,” said Barbara Berrie, who leads the Scientific Research Department at the National Gallery of Art and served as a co-leader of the study. “We want to make sure we understand what’s going on in more contemporary paintings so that these works are here for the future.”

    The study could have broader implications for developing better methods for conservation based around the observed chemistry in oil paints, she said. “I can see this maybe being applied generally to issues of preservation and treatments for all kinds of works of art,” she said.

    Dula Parkinson, a staff scientist at the ALS who participated in the study, said the X-rays revealed the size, shape, and distribution of tiny spots resembling bubbles in a paint sample that measured just a couple of millimeters across.

    “They wanted to understand the basic chemistry and basic processes of what was going on,” he said. “These structures that they see are really common in lots of paintings, and so they’re trying to see why these structures are here.” The imaging, using a technique called X-ray microtomography, mapped varied thicknesses in the paint and revealed some microscopic cracking.

    Microtomography at the ALS has also been used to provide microscopic views of a wide range of samples, from plant stems to spacecraft heat shields.

    Besides the X-ray exploration of a paint sample at the microscale, the team also used a technique known as photothermal induced resonance (PTIR) that exceeded the magnification limits of conventional light-based microscopes. PTIR couples infrared (IR) lasers with an atomic force microscope to provide a nanoscale window into the paint’s chemistry at a scale much smaller than is achievable with conventional IR microscopes.

    Another technique, called Fourier transform infrared (FTIR) micro spectroscopy, provided a broader view of the chemical composition across varying layers of paint samples.

    Andrea Centrone, a project leader for the Nanoscale Spectroscopy Group at NIST who co-led the study with Berrie, noted that the PTIR technique provides chemical mapping with resolution similar to that of atomic-force microscopy – which offers a scan of the sample via a process that is similar to a record player’s needle moving over a surface and mapping it

    While the tip scans over the sample, infrared pulses are absorbed locally and the sample heats up and expands rapidly. This “kicks” the tip like a struck tuning fork and provides chemically specific information about the sample.

    The paint sample had a very rough, sticky surface that was difficult to chemically map, so Centrone worked with collaborators at NIST to adapt the technique so that the scanning tip oscillated above the sample surface, touching it gently instead of dragging across it, allowing the capture of high-resolution data.

    “We are able to capture very small details down to 10 or 20 nanometers,” or billionths of a meter, Centrone said. “We were able to detect which kind of metal soap had formed in the paint samples.”

    The study notes that the same techniques that were used in combination to explore the paint chemistry could be applied more broadly in other fields where the samples are challenging because their chemistry isn’t uniform, and detailed knowledge of chemistry over different scales is required, such as in biomedicine and energy storage. 

    Berrie said she looks forward to future studies that apply the same techniques to explore different types and layers of paint and other issues for preservation of works of art. 

    “We hope that we will be able to do some comparing and contrasting of different combinations of oil-pigment interactions,” she said. “We will be able to explore some of the underlying chemistry of paintings that we still don’t know much about,” to provide insight for art preservation, too. “And, we are trying to help inform the range of choices that art conservators have.”

    The ALS is a DOE Office of Science User Facility.

    Researchers from Berkeley Lab, the National Gallery of Art, the National Institute of Standards and Technology, the European research platform on ancient materials IPANEMA (CNRS), Université de Versailles Saint-Quentin-en-Yvelines, Université Paris-Saclay, the University of Maryland, and William & Mary participated in the study.

    The work was supported by the DOE Office of Science’s Basic Energy Sciences program, the Charles E. Culpeper Advanced Fellowship at the National Gallery of Art, and the University of Maryland through a Cooperative Research Agreement between the University of Maryland and the National Institute of Standards and Technology Center for Nanoscale Science and Technology.

    ###

    Founded in 1931 on the belief that the biggest scientific challenges are best addressed by teams, Lawrence Berkeley National Laboratory and its scientists have been recognized with 13 Nobel Prizes. Today, Berkeley Lab researchers develop sustainable energy and environmental solutions, create useful new materials, advance the frontiers of computing, and probe the mysteries of life, matter, and the universe. Scientists from around the world rely on the Lab’s facilities for their own discovery science. Berkeley Lab is a multiprogram national laboratory, managed by the University of California for the U.S. Department of Energy’s Office of Science.

    DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

    The conservation division of the National Gallery of Art is responsible for the preservation and study of works of art in the Gallery’s collection. The division comprises departments that specialize in the treatment and care of paintings, works on paper, objects, photographs, textiles, and frames. Departments that support the mission of the entire division are preventive conservation, scientific research, analytical imaging, and administration.

    • other-fb
    • other-tw
    X
    X
    X
    • Filters

    • × Clear Filters
    Bio-circuitry mimics synapses and neurons in a step toward sensory computing

    Bio-circuitry mimics synapses and neurons in a step toward sensory computing

    Researchers at the Department of Energy's Oak Ridge National Laboratory, the University of Tennessee and Texas A&M University demonstrated bio-inspired devices that accelerate routes to neuromorphic, or brain-like, computing.

    Staircase to the stars: Turbulence in fusion plasmas may not be all bad

    Staircase to the stars: Turbulence in fusion plasmas may not be all bad

    Surprise discovery shows that turbulence at the edge of the plasma may facilitate production of fusion energy.

    Study shows a much cheaper catalyst can generate hydrogen in a commercial device

    Study shows a much cheaper catalyst can generate hydrogen in a commercial device

    SLAC and Stanford researchers have shown for the first time that a cheap catalyst can split water and generate hydrogen gas for hours on end in the harsh environment of a commercial electrolyzer - a step toward large-scale hydrogen production for fuel, fertilizer and industry.

    Unlocking the Biochemical Treasure Chest Within Microbes

    Unlocking the Biochemical Treasure Chest Within Microbes

    An international team of scientists lead by the Joint Genome Institute has developed a genetic engineering tool that makes producing and analyzing microbial secondary metabolites - the basis for many important agricultural, industrial, and medical products - much easier than before, and could even lead to breakthroughs in biomanufacturing.

    Scientists Pinpoint Cause of Harmful Dendrites and Whiskers in Lithium Batteries

    Scientists Pinpoint Cause of Harmful Dendrites and Whiskers in Lithium Batteries

    Scientists have uncovered a root cause of the growth of needle-like structures--known as dendrites and whiskers--that plague lithium batteries, sometimes causing a short circuit or failure. The defects are a major factor holding back the batteries from broader widespread use and further improvement.

    Argonne and University of Illinois to form hydrogen fuel cell coalition

    Argonne and University of Illinois to form hydrogen fuel cell coalition

    Argonne and University of Illinois announce intent to form the Midwest Hydrogen and Fuel Cell Coalition.

    Six Degrees of Nuclear Separation

    Six Degrees of Nuclear Separation

    For the first time, Argonne scientists have printed 3D parts that pave the way to recycling up to 97 percent of the waste produced by nuclear reactors. From left to right: Peter Kozak, Andrew Breshears, M Alex Brown, co-authors of a recent Scientific Reports article detailing their breakthrough. (Image by Argonne National Laboratory.)

    Shaping nanoparticles for improved quantum information technology

    Shaping nanoparticles for improved quantum information technology

    Argonne researchers find that semiconductor nanoparticles in the shape of rings have attractive properties for quantum networking and computation.

    Science Snapshots - Waste to fuel, moire superlattices, mining cellphones for energy data

    Science Snapshots - Waste to fuel, moire superlattices, mining cellphones for energy data

    Science Snapshots - Waste to fuel, moire superlattices, mining cellphones for energy data

    New Electrolyte Stops Rapid Performance Decline of Next-Generation Lithium Battery

    New Electrolyte Stops Rapid Performance Decline of Next-Generation Lithium Battery

    Researchers at Argonne National Laboratory have designed and tested a new electrolyte composition that could greatly accelerate the adoption of the next generation of lithium-ion batteries.


    • Filters

    • × Clear Filters
    Barbara Jacak Receives 2019 Distinguished Scientist Fellow Award

    Barbara Jacak Receives 2019 Distinguished Scientist Fellow Award

    Barbara Jacak, director of Lawrence Berkeley National Laboratory's Nuclear Science Division since 2015, has been named a 2019 Distinguished Scientist Fellow by the U.S. Department of Energy's Office of Science.

    Two Brookhaven Lab Scientists Named DOE Office of Science Distinguished Fellows

    Two Brookhaven Lab Scientists Named DOE Office of Science Distinguished Fellows

    Scientists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have garnered two out of five "Distinguished Scientists Fellow" awards announced today by the DOE's Office of Science. Theoretical physicist Sally Dawson, a world-leader in calculations aimed at describing the properties of the Higgs boson, and Jose Rodriguez, a renowned chemist exploring and developing catalysts for energy-related reactions, will each receive $1 million in funding over three years to pursue new research objectives within their respective fields.

    Department of Energy Announces Private-Public Awards to Advance Fusion Energy Technology

    The U.S. Department of Energy (DOE) announced funding for 12 projects with private industry to enable collaboration with DOE national laboratories on overcoming challenges in fusion energy development. The awards are the first provided through the Innovation Network for Fusion Energy program (INFUSE).

    Denisov Leads High Energy Physics at Brookhaven

    Denisov Leads High Energy Physics at Brookhaven

    Dmitri Denisov, a leading physicist and spokesperson of the DZero experiment, has been named Deputy Associate Lab Director for High Energy Physics at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory.

    Chemistry Postdoc Receives Battery500 Young Investigator Award

    Chemistry Postdoc Receives Battery500 Young Investigator Award

    Zulipiya Shadike, a postdoctoral fellow in the Chemistry Division at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory, received a Young Investigator Award from the Battery500 Consortium, a DOE-sponsored consortium led by Pacific Northwest National Laboratory (PNNL) that aims to improve electric vehicle batteries.

    Two Brookhaven Lab Scientists Named Fellows of the American Physical Society

    Two Brookhaven Lab Scientists Named Fellows of the American Physical Society

    The American Physical Society (APS) has elected two scientists from Brookhaven National Laboratory as 2019 APS fellows.

    Versatile physics leader Stefan Gerhardt elected an APS fellow

    Versatile physics leader Stefan Gerhardt elected an APS fellow

    Profile of physicist Stefan Gerhardt who has been elected a 2019 fellow of the American Physical Society.

    PNNL, Sandia, and Georgia Tech Join Forces in AI Effort

    PNNL, Sandia, and Georgia Tech Join Forces in AI Effort

    Scientists from DOE's Pacific Northwest National Laboratory, DOE's Sandia National Laboratories, and the Georgia Institute of Technology will collaborate on solutions to some of the most challenging problems in AI today, thanks to $5.5 million in funding from DOE.

    Argonne Receives More Than $1 Million for Quantum Information Science

    Argonne Receives More Than $1 Million for Quantum Information Science

    Argonne scientists receive $1.19 million from DOE for quantum research.

    Department of Energy Announces $6.6 Million to Study Dark Matter

    The U.S. Department of Energy (DOE) announced $6.6 million for four new research awards to develop design concepts for dark matter search experiments.


    • Filters

    • × Clear Filters
    Tune in to Tetrahedral Superstructures

    Tune in to Tetrahedral Superstructures

    Shape affects how the particles fit together and, in turn, the resulting material. For the first time, a team observed the self-assembly of nanoparticles with tetrahedral shapes.

    Tracing Interstellar Dust Back to the Solar System's Formation

    Tracing Interstellar Dust Back to the Solar System's Formation

    This study is the first to confirm dust particles pre-dating the formation of our solar system. Further study of these materials will enable a deeper understanding of the processes that formed and have since altered them.

    Investigating Materials that Can Go the Distance in Fusion Reactors

    Investigating Materials that Can Go the Distance in Fusion Reactors

    Future fusion reactors will require materials that can withstand extreme operating conditions, including being bombarded by high-energy neutrons at high temperatures. Scientists recently irradiated titanium diboride (TiB2) in the High Flux Isotope Reactor (HFIR) to better understand the effects of fusion neutrons on performance.

    Better 3-D Imaging of Tumors in the Breast with Less Radiation

    Better 3-D Imaging of Tumors in the Breast with Less Radiation

    In breast cancer screening, an imaging technique based on nuclear medicine is currently being used as a successful secondary screening tool alongside mammography to improve the accuracy of the diagnosis. Now, a team is hoping to improve this imaging technique.

    Microbes are Metabolic Specialists

    Microbes are Metabolic Specialists

    Scientists can use genetic information to measure if microbes in the environment can perform specific ecological roles. Researchers recently analyzed the genomes of over 6,000 microbial species.

    Even Hard Materials Have Soft Spots

    Even Hard Materials Have Soft Spots

    The Achilles Heel of "metallic glasses" is that while they are strong materials--even stronger than conventional steels--they are also very brittle. The initial failures tend to be localized and catastrophic. This is due to their random amorphous (versus ordered crystalline) atomic structure. Computer simulations revealed that the structure is not completely random, however, and that there are some regions in the structure that are relatively weak. Defects nucleate more easily in these regions, which can lead to failure. This understanding of the mechanical properties has led to a strategy for making the material stronger and less brittle.

    2-D Atoms Do the Twist

    2-D Atoms Do the Twist

    In the study, scientists demonstrated, for the first time, an intrinsically rotating form of motion for the atoms in a crystal. The observations were on collective excitations of a single molecular layer of tungsten diselenide. Whether the rotation is clockwise or counter-clockwise depends on the wave's propagation direction.

    Location, Location, Location... How charge placement can control a self-assembled structure

    Location, Location, Location... How charge placement can control a self-assembled structure

    For years, scientists have formed polymers using the interaction of charges on molecular chains to determine the shape, geometry, and other properties. Now, a team achieved precise and predictable control of molecular chains by positioning charges. Their method leads to particles with reproducible sizes.

    Cracking in Harsh Environments Needs Stress and Corrosion, But Not at the Same Time

    Cracking in Harsh Environments Needs Stress and Corrosion, But Not at the Same Time

    Alloys (metals combining two or more metallic elements) are typically stronger and less susceptible to cracking than pure metals. Yet when alloys are subjected to stress and a harsh chemical environment, the alloy can fail. The reason? Cracks caused by corrosion.

    Simultaneous Clean and Repair

    Simultaneous Clean and Repair

    Scientists have developed a novel and efficient approach to surface cleaning, materials transport, and repair.


    Spotlight





    Showing results

    0-4 Of 2215