The origin of nanomaterials
2018-11-09
Nano-metal materials (like nano silicon powder, nano silver powder) were successfully developed in the mid-1980s. Later, nano-semiconductor films, nano-ceramics, nano-ceramic materials and nano-biomedical materials were introduced.
The discovery of nanomaterials The material particles of the constituent materials have become smaller. Will the "small dots" be very different from the nature of "big men"? This is the scientific idea of the German physicist Grant, the discoverer of nanomaterials.
It was a day in 1980, when Gretel traveled to Australia. When he drove across Australia's desert, the empty, lonely and lonely environment made his thinking particularly active and sensitive. He has long been engaged in the study of crystalline materials. Understanding the crystal grain size has a great influence on the properties of the material: the smaller the grain, the higher the strength.
The idea above Glitter is only the general law of the material. His idea goes deeper and step by step: If the crystals of the crystals that make up the material are only a few nanometers in size, what would the material look like? Maybe there will be a "overwhelming change"!
After Glett returned to China with these ideas, he immediately began experimenting. After nearly four years of hard work, in 1984, ultra-fine powders of only a few nanometers in size, including ultrafine powders of various metals, inorganic compounds and organic compounds, were produced.
Glitter discovered a very interesting phenomenon when studying these ultrafine powders. It is well known that metals have a variety of different colors, such as gold is golden yellow, silver is silver white, and iron is grayish black. As for materials other than metals, such as inorganic compounds and organic compounds, they can also carry different colors: the glaze on the porcelain has always been colorful, and the dyes composed of various organic compounds are more vivid.
However, once all of these materials are made into ultrafine powders, their color is always black: the glaze, dyes and various metals on the porcelain become a color - black. Just as Glett imagined, "small but not" compared to the "big man", the performance has changed "overwhelming".
Why, no matter what material, once made into nano "small dots", it will become black? Originally, when the particle size of the material became smaller than the wavelength of the light wave, its ability to reflect light became very low, about as low as less than 1%. Since the ultra-fine powder has little ability to reflect light, the nanomaterials we see are all black.