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BROOKHAVEN NATIONAL LABORATORY / SCIENCE PHOTO LIBRARY BROOKHAVEN NATIONAL LABORATORY / SCIENCE PHOTO LIBRARY
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Brookhaven National Laboratory chemist Wei-Qiang Han, and his colleagues are in the midst of ongoing research into the structure and properties of cerium oxide nanotubes. As part of this, they have devised a method to synthesize cerium oxide nanotubes of high quality. First, they allow the compounds cerium nitrate and ammonia hydroxide to chemically react. Initially, this reaction forms ''one-dimensional'' nanostructures, such as rods and sheets, made of the intermediate product cerium hydroxide. The intermediate product is then quickly cooled to zero degrees Celsius, which freezes those structures into place. By letting the chemical reaction proceed over a long period of time, a process called ''aging,'' the hydrogen is eventually removed from the intermediate product and a large quantity of the desired end product - cerium oxide nanotubes - is formed. Chemists and materials scientists often study ''nanotubes'' - capsule-shaped molecules only a few billionths of a meter (nanometers) in width. In nanotube form, many materials take on useful, unique properties, such as physical strength and excellent conductivity. Carbon nanotubes are the.
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