纳米（Nanometer）.docVIP

纳米（Nanometer） Characteristics and applications of nano solid materials Text: Nano materials are generally divided into nanoparticles, nano films (multilayers and granular films), nano solids. Nanoparticles are typical representatives of nano systems, generally spherical or globular (closely related to the preparation method). It belongs to the range of ultramicro particles (1 ~ 1000nm). Due to its small size, large specific surface size and quantum size effect, it has different characteristics than conventional solids, and is different from the size effect in traditional materials science. For example, when the size is reduced to several nanometers, the original is a good conductor metal to insulator, insulator for typical covalent polar resistance greatly decreased or even become a conductor, semiconductor for type P may become n. The conventional solid under certain conditions, its physical properties are stable, while in the nano state the performance was strongly affected by the particle size, appearance of magic effect. From the application perspective, nanoparticles surface effect makes it has great application prospect in catalysis, powder metallurgy, fuel, magnetic recording, coating, heat transfer, radar stealth, light absorption, photoelectric conversion, gas sensing etc.. Nano solid material is a new kind of material with broad application prospects. It is a kind of artificial condensed solid which is pressed and sintered by nanometer superfine particles. This material has a new type of solid structure, which is different from crystalline or amorphous materials of the same kind, so it is called nano solid material. In 1963, Professor Da Ryoji of Nagoya University in Japan first obtained surface cleaning nanoparticles by evaporative condensation. In 1984, a team led by Professor H. Wright, of Germany, first made the first batch of artificial metal solids (Cu, Pa, Ag and Fe). The same year the United States Argonne laboratory developed TiO2 nano solid. In t