Nanotechnology is playing an ever more important role in the materials sciences too. The reason is that particles measuring between one and 100 nanometres frequently display optical, mechanical and chemical properties that are not observed on a macroscopic scale. Nanoparticles can increase the scratch resistance of automotive paints, for example, and impede the spread of fractures in composite materials. “In this way, we can achieve greater stability while using the same amount of material,” says materials expert Weigand. “This approach is considered extremely promising for plastic composites in lightweight construction for aircraft.” 
   
The most conservative way to produce nanoparticles is to grow them layer by layer from a nucleus and to interrupt the growth when the intended size is reached. Conversely, the particles can also be ground from a coarse material — like flour from grain in a flour mill. In this case, however, the tiny particles tend to clump together, losing the desired properties in the process. “The trick is not so much producing nanoparticles as it is stabilising them over long periods and preventing them from growing together into larger crystals or clumps again,” says pharmaceuticals expert Markus Weigandt. “This is a core area of expertise that Merck has from the chemicals sector, and we’re profiting from it in the pharmaceuticals business sector too.”