Atomic oxygen: useful properties. What is atomic oxygen?

Imagine an invaluable picture that was spoiled by a devastating fire. Fine paints, painstakingly applied in a variety of 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 which an invisible powerful substance called atomic oxygen is created. Within a few hours or days slowly, but surely the raid goes away, and the colors start to appear again. Covered with a fresh layer of clear lacquer, the picture returns to its former glory.

It may seem that this is magic, but this is science. The method developed by scientists at the Glennovsky Research Center (GIC) of NASA uses atomic oxygen to preserve and restore works of art that would otherwise have been irreparably damaged. The substance is also capable of completely sterilizing surgical implants designed for the human body, which significantly reduces the risk of inflammation. For patients with diabetes, it can improve the glucose monitoring device, which requires only a portion of the blood previously required for testing so that patients can control their condition. 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, occurs in the upper layers of the Earth's atmosphere.

Atomic oxygen in natural conditions on the Earth's surface can not 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 decay, forming an atomic form. The atmosphere in low Earth orbit is 96% composed of atomic oxygen. At the dawn of space shuttle NASA missions, its presence caused problems.

Harm to good

According to Bruce Banks, a senior physicist at Alpaport, which studies the space environment at the Glenn Center branch, after the first few shuttle flights, the materials of its structure looked as if they were covered with frost (they were strongly eroded and textured). Atomic oxygen reacts with organic materials of the covering of space vehicles, gradually damaging them.

The Municipal Information Center undertook an investigation into the causes of the damage. As a result, the 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 a spacecraft is in low-earth orbit (where manned vehicles are departing and where the ISS is based), atomic oxygen, formed from the residual atmosphere, can react with the surface of spacecraft, as a result of which they are damaged. When developing the power supply system of the station, there were fears that solar cell batteries made of polymers would undergo rapid destruction due to the action of this active oxidizer.

Flexible glass

NASA found a solution. A group of scientists from the Glenn Research Center developed a thin film coating for solar cells that was immune to the action of the aggressive element. Silicon dioxide, or glass, is already oxidized, so it can not be damaged by atomic oxygen. The researchers created a coating of transparent silicon glass, so thin that it became flexible. This protective layer firmly adheres to the polymer of the panel and protects it from erosion, without impairing any of its thermal properties. The coating still successfully protects the solar cells of the International Space Station, and also was used to protect the photocells of the Mir station.

According to Banks, solar panels have successfully withstood more than ten years of stay in space.

The Taming of Power

Having conducted hundreds of tests that were part of the development of a coating resistant to atomic oxygen, a group of scientists from the Glenn 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, the erosion of organic materials. The properties of atomic oxygen are such that it is able to remove any organic matter, a hydrocarbon that does not so easily react with conventional chemicals.

The researchers found many ways to use it. They learned that atomic oxygen transforms the surfaces of silicones into glass, which can be useful in creating components with a sealed seal without sticking to each other. This process was designed to seal the International Space Station. In addition, scientists have discovered that atomic oxygen can restore and preserve damaged artwork, improve the materials of aircraft structures, and also benefit people, since it can be used in a variety of biomedical applications.

Cameras and Portable Devices

There are various ways to influence atomic oxygen on the surface. Vacuum chambers are most often used. They vary in size from the shoe box to the installation of 1.2 x 1.8 x 0.9 m. With the help of microwave or radio frequency radiation, O ₂ molecules break up to the state of atomic oxygen. A polymer sample is placed in the chamber, the level of erosion of which indicates the concentration of the active substance inside the unit.

Another way of applying the substance is a portable device that allows you to direct a narrow stream of oxidant 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 continues, an increasing number of industries are interested in using atomic oxygen. NASA has organized many partnerships, joint ventures and subsidiaries, which in most cases have become successful in various commercial areas.

Atomic oxygen for the body

The study of the scope of this chemical element is not limited to outer space. Atomic oxygen, the useful properties of which are determined, but even more to be studied, found many medical applications.

It is used for texturing 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 causes another benefit that atomic oxygen brings - treatment of diseases of the musculoskeletal system.

This oxidizer can also be used to remove biologically active contaminants from surgical implants. Even with modern practice of sterilization from the surface of implants, it is difficult to remove all remnants of bacterial cells called endotoxins. These substances are organic, but not live, so sterilization is not capable of removing 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 useful properties of which allow you to clean the prosthesis and remove all traces of organic materials, significantly reduces the risk of postoperative inflammation. This results in improved surgical outcomes and reduced 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 blood serum more efficient contact with the monitor's chemical sensing component.

According to Sharon Miller, an electrical engineer in the Space Environment and Experiments Department of the NASA Glenov Research Center, this makes the test more accurate, and a much smaller amount of blood is required to measure the blood sugar level of the test person. You can make a shot practically at any part of the body and get enough blood to establish the level of sugar.

Another way to get atomic oxygen is hydrogen peroxide. It is a much stronger oxidant than molecular. This is due to the ease with which peroxide decomposes. Atomic oxygen, formed in this case, acts much more energetically than molecular oxygen. This is the reason for the practical application of hydrogen peroxide: the destruction of molecules of colorants and microorganisms.

Restoration

When art works are exposed to the danger of irreversible damage, atomic oxygen can be used to remove organic contaminants, which will leave the picture material safe. The process removes all organic materials, such as carbon or soot, but, as a rule, does not affect the paint. Pigments are mostly of inorganic origin and already oxidized, which means that oxygen will not damage them. Organic dyes can also be stored by carefully counting the exposure time. The canvas is in complete safety, since atomic oxygen is in contact only with the surface of the picture.

Works of art are placed in a vacuum chamber in which this oxidizer is formed. Depending on the degree of damage, the picture can remain there for 20 to 400 hours. For special treatment of the damaged area, which needs restoration, a stream of atomic oxygen can also be used. This eliminates the need to place artwork in a vacuum chamber.

Soot and lipstick - not a problem

Museums, galleries and churches began to contact the Municipal Information Center to preserve and restore their works of art. The research center demonstrated the ability to restore the damaged picture of Jackson Pollack, remove the lipstick from the canvas of Andy Warhol and save the smoke-damaged canvases of St. Stanislaus Church in Cleveland. The team of the Glenn Research Center used atomic oxygen to restore a fragment that was considered lost, centuries ago, the Italian copy of Rafael's painting Madonna in a Chair, owned by the Episcopal Church of St. Alban in Cleveland.

According to Banks, this chemical element is very effective. In artistic restoration it works perfectly. True, this is not something that can be purchased in a bottle, but much more effective.

Learning the future

NASA on a reimbursable basis worked with many parties interested in atomic oxygen. Glennovsky Research Center served individuals whose priceless works of art were damaged by domestic fires, as well as corporations seeking the use of this 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 technologies.

Space in the service of man

The group of scientists hopes to continue studying the ways of using atomic oxygen, as well as the already found promising directions. 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 the exploration of space and life on Earth. Whether it is the preservation of priceless works of art or the improvement of people, atomic oxygen is the strongest means. Work with him is rewarded a hundredfold, and her results are immediately visible.