Imagine a priceless picture that has been corrupted by a devastating fire. Fine paints, painstakingly applied in many shades, disappeared under the layers of black soot. It would seem that the masterpiece is irretrievably lost.
Scientific magic
But do not despair. The picture is placed in a vacuum chamber, inside of which an invisible powerful substance is created, called atomic oxygen. Within a few hours or days, the plaque slowly but surely leaves, and the colors begin to appear again. Covered with a fresh layer of clear varnish, the painting returns to its former glory.
It may seem like magic, but it is science. The method, developed by scientists at NASA’s Glenn Research Center (GIC), uses atomic oxygen to preserve and restore works of art that would otherwise cause irreparable damage. The substance is also capable of completely sterilizing surgical implants intended for the human body, which significantly reduces the risk of inflammation. For patients with diabetes, it can improve the glucose monitoring device, which will require only a portion of the blood previously needed for testing so that patients can monitor their condition. The substance can texture the surface of polymers for better adhesion of bone cells, which opens up new possibilities in medicine.
And this powerful substance can be obtained directly from the air.
Atomic and molecular oxygen
Oxygen exists in several different forms. The gas we breathe is called O 2 , that is, it consists of two atoms. There is also atomic oxygen, the formula of which is O (one atom). The third form of this chemical element is O 3 . This is ozone, which, for example, is found in the upper atmosphere of the Earth.
Atomic oxygen under natural conditions on the surface of the Earth cannot exist for a long time. It has an extremely high reactivity. For example, atomic oxygen in water forms hydrogen peroxide. But in space, where there is a large amount of ultraviolet radiation, O 2 molecules more easily disintegrate, forming an atomic form. The atmosphere in low Earth orbit is 96% atomic oxygen. At the dawn of NASA's space shuttle flights, its presence was causing problems.
Harm for the good
According to Bruce Banks, a senior physicist at Alfaport, who is researching the space environment at a branch of the Glenn Center, after the first few shuttle flights, his materials looked like they were covered with frost (they were heavily eroded and textured). Atomic oxygen reacts with the organic materials of the spacecraft lining, gradually damaging them.
GIC is investigating the causes of the damage. As a result, researchers not only created methods for protecting spacecraft from atomic oxygen, they also found a way to use the potential destructive power of this chemical element to improve life on Earth.
Erosion in space
When the spacecraft is in low Earth orbit (where the manned spacecraft is launched and where the ISS is based), atomic oxygen generated from the residual atmosphere can react with the surface of the spacecraft, as a result of which they are damaged. When developing the station’s power supply system, there were concerns that solar cell batteries made from polymers would undergo rapid destruction due to the action of this active oxidizing agent.
Flexible glass
NASA has found a solution. A group of scientists from the Glennov Research Center developed a thin film coating for solar panels that was immune to the action of an aggressive element. Silicon dioxide, or glass, is already oxidized, so it cannot be damaged by atomic oxygen. The researchers created a coating of transparent silicon glass, so thin that it became flexible. This protective layer adheres tightly to the polymer of the panel and protects it from erosion, without compromising any of its thermal properties. The coating still successfully protects the solar panels of the International Space Station, and was also used to protect the photocells of the Mir station.
According to Banks, solar panels have successfully withstood more than ten years in space.
Taming the force
Having carried out hundreds of tests that were part of the development of a coating resistant to atomic oxygen, a group of scientists from the Glennov Research Center gained experience in understanding how this chemical works. Experts saw other possibilities of using an aggressive element.
According to Banks, the group became aware of a change in surface chemistry and erosion of organic materials. The properties of atomic oxygen are such that it is able to remove any organics, hydrocarbon, which does not easily react with ordinary chemicals.
Researchers have discovered many ways to use it. They learned that atomic oxygen turns silicon surfaces into glass, which can be useful when creating components with hermetic sealing without sticking to each other. This process was developed to seal the International Space Station. In addition, scientists have found that atomic oxygen can repair and preserve damaged artwork, improve aircraft structural materials, and also benefit people, as it can be used in many biomedical applications.
Cameras and portable devices
There are various ways that atomic oxygen can act on a surface. The most commonly used vacuum chambers. In size, they range from a shoe box to an installation of 1.2 x 1.8 x 0.9 m. Using microwave or radio frequency radiation, O 2 molecules are broken down to the state of atomic oxygen. A polymer sample is placed in the chamber, the erosion level of which indicates the concentration of the active substance inside the unit.
Another method of applying the substance is a portable device that allows you to direct a narrow stream of oxidizing agent to a specific target. It is possible to create a battery of such streams, capable of covering a large area of the treated surface.
As further research is carried out, an increasing number of industries are showing an interest in the use of atomic oxygen. NASA has organized many partnerships, joint ventures and subsidiaries, which in most cases have been successful in various commercial fields.
Atomic oxygen for the body
The study of the areas of application of this chemical element is not limited to outer space. Atomic oxygen, the beneficial properties of which are determined, but still to be studied more, has found many medical applications.
It is used to texture the surface of polymers and makes them capable of fusing with bone. Polymers usually repel bone cells, but a chemically active element creates a texture that enhances adhesion. This leads to another benefit that atomic oxygen brings - the treatment of diseases of the musculoskeletal system.
This oxidizing agent can also be used to remove biologically active contaminants from surgical implants. Even with current sterilization practice, it is difficult to remove all bacterial cell residues called endotoxins from the surface of the implants. These substances are organic, but not living, so sterilization is not able to remove them. Endotoxins can cause post-implant inflammation, which is one of the main causes of pain and potential complications in patients with an implant.
Atomic oxygen, the beneficial properties of which allow you to clean the prosthesis and remove all traces of organic materials, significantly reduces the risk of postoperative inflammation. This leads to improved results of operations and a reduction in pain in patients.
Relief for Diabetics
The technology is also used in glucose sensors and other biomedical monitors. They use acrylic optical fibers textured with atomic oxygen. This treatment allows the fibers to filter out red blood cells, providing the serum with more effective contact with the chemical sensing component of the monitor.
According to Sharon Miller, an electrical engineer at the NASA’s Space Environment and Experiments Division, NASA’s Glenn Research Center, this makes the test more accurate, and much less blood is needed to measure the blood sugar level of the test person. You can give an injection on almost any part of the body and get enough blood to set the sugar level.
Another way to get atomic oxygen is hydrogen peroxide. It is a much stronger oxidizing agent than molecular. This is due to the ease with which peroxide decomposes. Atomic oxygen generated in this case acts much more energetically than molecular oxygen. This is the reason for the practical use of hydrogen peroxide: the destruction of molecules of coloring matter and microorganisms.
Restoration
When works of art are in danger of irreversible damage, atomic oxygen can be used to remove organic contaminants, which will preserve the material in the painting. The process removes all organic materials, such as carbon or soot, but, as a rule, does not affect the paint. Pigments are mainly of inorganic origin and are already oxidized, which means that oxygen will not damage them. Organic dyes can also be stored by carefully counting exposure times. The canvas is in complete safety, since atomic oxygen only contacts the surface of the painting.
Works of art are placed in a vacuum chamber in which this oxidizing agent is formed. Depending on the degree of damage, the picture may remain there from 20 to 400 hours. For special treatment of the damaged area in need of restoration, a stream of atomic oxygen can also be used. This eliminates the need to place artwork in a vacuum chamber.
Soot and lipstick are not a problem
Museums, galleries and churches began to turn to the GIC to preserve and restore their works of art. The research center has demonstrated the ability to restore Jackson Pollack’s damaged painting, remove lipstick from Andy Warhol’s canvas, and preserve smoke-damaged canvases from St. Stanislaus Church in Cleveland. The team at the Glennov Research Center used atomic oxygen to restore a fragment that was thought to be lost, a centuries-old Italian copy of Raphael's Madonna in the Chair, owned by St. Alban’s Episcopal Church in Cleveland.
According to Banks, this chemical element is very effective. In the art restoration, he works perfectly. True, this is not something that can be purchased in a bottle, but it is much more effective.
Exploring the future
NASA has been working with many parties interested in atomic oxygen on a reimbursable basis. The Glenn Research Center served private individuals whose priceless artworks were damaged by house fires, as well as corporations looking to use the substance in biomedical applications, such as LightPointe Medical from Eden Prairie, Minnesota. The company has discovered many uses of atomic oxygen and is going to find even more.
According to Banks, there are many unexplored areas. A significant number of applications for space technology have been discovered, but probably even more are hidden outside space technology.
Space in the service of man
A group of scientists hopes to continue exploring ways to use atomic oxygen, as well as already found promising areas. Many technologies have been patented, and the GIC team hopes that companies will license and commercialize some of them, which will bring even more benefit to humanity.
Under certain conditions, atomic oxygen can cause damage. Thanks to NASA researchers, this substance is currently making a positive contribution to space exploration and life on Earth. Whether it is the preservation of priceless works of art or the healing of people, atomic oxygen is a powerful tool. Work with him is rewarded a hundredfold, and its results become visible immediately.