TiO2_d

© BAM

They are found in toothpaste, cosmetics and food. In clothing, cell phone chips, medicines and even airplane parts: Nanomaterials. The individual particles are so tiny that they can only be seen under a scanning electron microscope: No wonder, because they measure only 1 to 100 nanometers, or one millionth to one ten-thousandth of a millimeter. By comparison, a human hair is several hundred times thicker.

For some years now, the chemical industry has been adding more and more of the tiny particles to its products. Because their tininess has a decisive advantage: nanoparticles have a particularly favorable surface-to-volume ratio.

20D100-19

Every single drop contains thousands of particles. They only become visible when magnified over a hundred thousand times.

© BAM

However, it is on the surface of a substance that the chemical reactions take place. Nanomaterials can be specifically processed in such a way that they cause water droplets to roll off car paint, bacteria to die in functional clothing, or shirts not to wrinkle. They make lipsticks and wall paints glow or ensure that drugs can be better absorbed by the body.

Despite all these great advantages: It has not yet been adequately researched whether the particles do not also pose risks to humans and the environment. On behalf of the European Commission, BAM is therefore investigating the safety of nanomaterials together with six other metrological institutes on the continent.

TiO2_c

BAM's special mission: to develop standards and procedures for the exact measurement and characterization of nanoparticles. This is easier said than done. Because nanoparticles are not only extremely small. They can also have very different shapes: round and regular, but also jagged like a mountain range or porous like a crater landscape. Some resemble cigars, double pyramids, cubes or even plates stacked on top of each other like books.

20D100-28

The measurement of nanoparticles is a prerequisite for being able to reliably evaluate the toxicological properties of the substances.

© BAM

BAM uses its particularly powerful electron microscopes to measure nanoparticles. A special computer program evaluates the images. It calculates an average value from hundreds of nanoparticles of a substance.

With its data, BAM thus creates the prerequisite for other institutes to evaluate the chemical and toxicological properties of nanoparticles. And people and the environment are protected against possible damage from the technology of the future.

Further information on nanotechnology at BAM can be found at www.bam.de/nanotechnology.