Nanoscale Elements in Traditional Technologies

From the present knowledge of materials it is understood that the beautiful colors of stained glass windows originate in nanometer scale metal particles present in the glass. These metal particles have scattering resonances for light of specific wavelengths, depending on the particle size L. The particle size distribution, in turn, will depend upon the choice of metal impurity, its concentration, and the heat treatment of the glass. When the metallic particles in the glass are illuminated, they preferentially scatter light of particular colors. Neutral density filters marketed for photographic application also have distributions of small particles embedded in glass.

Carbon black, commonly known as soot, which contains nanometer-sized particles of carbon, was used very early as an additive to the rubber in automobile tires.

(As we now know, carbon black contains small amounts of 60C (Buckminsterfuller-ene), other fullerenes, and graphitic nanotubes of various types.)

The AgBr and Agl crystals of conventional photography are nanometer-sized single crystals embedded in a thin gelatin matrix. It appears that the fundamental light absorption in these crystals is close to the quantum sensitivity limit. It further appears that the nanoscopic changes in these tiny crystals, which occur upon absorption of one or more light photons, enable them to be turned into larger metallic silver particles in the conventional photographic development process. The conventional photographic negative image is an array of solid silver grains embedded in a gelatin matrix. As such it is remarkably stable as a record, over decades or more.

The drugs that are so important in everyday life (and are also of huge economic importance), including caffeine, aspirin and many more, are specific molecules of nanometer size, typically containing fewer than 100 atoms.

Controlled precipitation chemistry for example is employed to produce uniform nanometer spheres of polystyrene, which have long been marketed as calibration markers for transmission electron microscopy.

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