Nanomaterial

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In principle, a nanomaterial is a material whose individual units are between 1 and 1000 nanometers (10 −9 meters, billionths of a meter) in size . Usually, substances in the nanoscale range (1 nm - 100 nm) are regarded as nanomaterials.

Natural nanomaterials

Some examples from living nature: The fine structure of foraminifera and viruses ( capsid ), the wax crystals on the upper side of a lotus or watercress leaf , silk (such as caterpillar , spider , spider mite and byssus ), the exoskeleton of arthropods (with feet , antennas and mouthparts ), the blue coloration of spiders, the adhesive hairs of gecko feet , butterfly shed , collagen , natural colloids (such as milk , blood ), keratinized tissue (such as skin , claws , beaks , feathers , horns , hair ), vascular bundle , xylem , Cotton , mother-of-pearl , corals and our bone matrix are natural organic nanomaterials.

Natural inorganic nanomaterials are the product of natural erosion ( clay minerals ) and / or volcanic activity ( opal ), but also forest fires. Targeted firing creates mineral pigments , cement , pyrogenic silicas, etc.

  • Scheme of an icosahedral capsid (the spheres correspond to the individual capsomeres.)

  • Lotus effect , water-repellent effect with self-cleaning ability

  • Close-up of the underside of a gecko foot walking on a glass wall (adhesive hairs: 200 × 10-15 nm).

  • SEM image of the fine structure of a butterfly scale (× 5000)

  • Peacock feather (detail)

  • Brazilian opal. Opalization occurs through reflection and interference of the light between silica gel spheres (150 to 400 nm).

  • Beaker of Lycurgus , glass, 4th century, Roman. Gold and silver nanoparticles (70 nm) dispersed in colloid form ensure the two colors (dichroism, red / green).

  • Blue coloration of a species of tarantula (450 nm ± 20 nm)

Synthetic nanomaterials

Materials composed of fullerenes (carbon "footballs" or nanotubes), industrial soot or nanoparticles ( nanoparticles , metals, metal and semi-metal oxides, metal sulfides, semiconductors or polymers).

Market size

The world market for (predominantly synthetic) nanomaterials is estimated at 11 million tons for 2011 with a value of 20 billion euros.

Legal definition

The definition of “nanomaterial” varies greatly between different institutions.

As nanomaterials are following the European Commission's 2011 materials referred since October 18, which is made of nano-objects (1 nm to 100 nm) in the unbound state, d. H. from aggregates or agglomerates , and have more than 50 percent of nano-objects in the number-weighted particle size distribution. All natural materials that arise and are produced in processes are recorded. By December 2014, this definition is to be reviewed in the light of experience gained and scientific and technological developments. In a first step, a collection of information on experiences with the definition was created and published on behalf of the EU Commission.

France has legally regulated the registration of nanomaterials based on the EU definition prior to import. Belgium and Denmark are planning their own databases for the registration of nanomaterials with significantly changed definitions.

In contrast, the Federal Environment Agency (Germany) proposes a uniform Europe-wide regulation and registration of all products containing nanomaterial.

Internationally, the terms and definitions of nanotechnology are specified in the ISO / TS 80004-1: 2015 standard.

criticism

The definition is criticized for being too broad and therefore also for centuries-old materials such as mineral pigments or everyday products. For example, materials that consist of coarse particles and contain a little abrasion can be classified as nanomaterial, while a fine powder with a narrow grain size distribution and a mean value of 110 nm would not fall under the definition.

In addition, there is no reliable measurement method with which everyday powders can be clearly classified as nanomaterial or not.

literature

See also

Web links

Individual evidence

  1. ↑ a b ISO / TS 80004-1: 2015. Nanotechnologies - Vocabulary - Part 1: Core terms. International Organization for Standardization, December 2015, accessed March 15, 2018 .
  2. ↑ Spider mite silk
  3. ↑ Why Are Tarantulas Blue?
  4. ↑ European Commission: Nanotechnology. Introduction , viewed December 10, 2013.
  5. ↑ Darrell R.Boverhof, Christina M. Bramante, John H. Butala, Shaun F. Clancy, Mark Lafranconi, Jay West, Steve C. Gordong: Comparative assessment of nanomaterial definitions and safety evaluation considerations. In: Regulatory Toxicology and Pharmacology, Volume 73, Issue 1. Elsevier , October 1, 2015, pp. 137–150 , accessed on July 3, 2018 .
  6. ↑ Press release of the European Commission: What is a “nanomaterial”? European Commission presents a common definition for the first time. 2011.
  7. ↑ European Commission: What is nanomaterial? Definition of the EU Commission. 2011.
  8. ↑ Towards a review of the EC Recommendation for a definition of the term "nanomaterial" Part 1
  9. ↑ Umweltbundesamt: Concept for a European register for products containing nanomaterials.
  10. ↑ Cefic: Practical definition is needed: Practical nanomaterials definition needed to push forward next great innovation breakthrough 2011.