The History and Applications of Nanomaterials
Naturally occurring nanomaterials have unique structures and properties. Examples include the structure of foraminifera, viruses, gecko feet, the wax crystals covering lotus and nasturtium leaves, and the silk of spiders and geckoes.
The American physicist Richard Feynman introduced the concept of nanotechnology in 1959. He envisioned building products atom-by-atom and down to the molecular level.
In 1959, physicist Richard Feynman first introduced the concept of nanotechnology when he presented his famous lecture, “There’s Plenty of Room at the Bottom.” This new field of research centers on materials that are small enough to be seen only with an electron microscope.
Artisans in Deruta, Italy, during the fifteenth and sixteenth centuries practiced early nanotechnology to create dramatic iridescent or metallic glazes for ceramics. These effects are due to varying the size of metal particles suspended in the glazes, which scatter light differently at different wavelengths for shimmering color and luster.
But the craftsmen who made these glazes were not nanotechnologists, because they did not know that they were creating a material at the nanoscale. A surviving example of their work is the Lycurgus Cup, which looks slate green under direct light but glows red when lit from the inside. This phenomenon, called dichroism, is due to gold and silver nanoparticles in the glass.
The synthesis of nanomaterials is the process by which atoms or molecules are assembled into structures with dimensions in the range of 1 to 100 nm. These structures exhibit distinct properties that are a result of their size.
Craftsmen in the fifteenth and sixteenth centuries of Deruta, Italy used a form of nanotechnology to create dramatic iridescent and metallic pottery glazes. They did this by incorporating silver and gold particles that scatter light at different wavelengths, producing the color variation.
Another example of nanotechnology is the carbon-based material known as fullerenes. When these are injected into lymphoma cells, they prevent the cancerous cell from “feeding” on actual cholesterol, starving it to death. The synthesis of these materials requires the use of special solvents, and the process is expensive. Plasma and flame pyrolysis are two popular methods for making nanoparticles, but they don’t offer much flexibility when it comes to design precision or customization. This is one reason why many companies that experiment with this type of synthesis turn to Cerion for help and advice.
A nanomaterial’s unique properties can be applied to a variety of products. For example, carbon nanotubes are being used in a number of consumer goods, including sports equipment and digital cameras, and quantum dots are semiconductor nanocrystals that can act like metals. Quantum dots have been used in a range of medical, scientific, and commercial applications.
Generally, there are two ways to create nanomaterials. One is “top-down” and involves converting bulk solids into their nano-sized components. The other is “bottom-up” and entails the self-assembly of atoms to create a nanostructured material.
In the lab, scientists use sophisticated tools such as electron microscopes to study nanomaterials and their properties. These instruments can see individual atoms and measure their chemical and physical characteristics. Engineered nanomaterials are being made and used for a wide range of commercial, industrial, and military applications. NIEHS is leading research efforts to understand how these materials affect the environment and human health, leveraging our world class toxicity testing capabilities.
A future with nanotechnology could lead to cars that convert more of the energy from gasoline into motion and electricity, and buildings that absorb sunlight to power them. It may also mean faster, more accurate medical tests that provide earlier diagnoses and better therapeutic success rates.
It may also mean clearer sunscreens that offer more protection against UV rays, wrinkle- and stain-resistant clothing, and deeper-penetrating therapeutic cosmetics. It might even lead to silver nanoparticles incorporated into bandages that smother and kill harmful bacteria.
Engineers who work with nanomaterials manipulate matter at the atomic and molecular level to create new materials that have novel properties. This sounds like a profoundly modern concept, but craftsmen from the premodern eras used similar methods. The Damascans, for example, crafted swords with exceptionally sharp edges and the Romans made iridescent glassware.