Популярно о нанотехнологиях в ангоязычном варианте

06.06.2015 Nanomaterials and Nanotechnology Products.

Nanomaterials and nanotechnology products have features or particle sizes in the range of 1 to 100 nm. Nanomaterials are made of carbon, ceramics, chemical precursors, ferrites, metals, minerals, polymers, semiconductors, and silica or silicates. Nanotechnology products are consolidated materials or devices that utilize nanostructures. Important specifications to consider when selecting nanomaterials and nanotechnology products include particle or feature size and specific surface area (SSA). Particle or feature size is the diameter or width of nanomaterials and nanotechnology products. SSA is measured in terms of mass per unit area and is easier to determine than crystal size. SSA can provide an indication of average particle size, but not particle size range or distribution. Typically, gas absorption techniques such as the Brunauer-Emmett-Teller absorption (BET) technique are used to determine SSA.

There are many types of nanomaterials and nanotechnology products. Fullerenes or buckyballs are carbon (C60) molecules with a cage-like structure of 60 or more atoms. Nanotubes are toroidal-shaped fullerene molecules or strings of stacked C60 carbon molecules. Both single-walled nanotubes (SWNTs) and double-walled (DWNTs) are available. Nanocrystals or quantum dots are used in optical displays, computer memory, cryptography, photovoltaics, storage media, flexible electronics, neural networks, telecommunications components, and quantum computing. Nanogels, aerogels, hydrogels and other nanoporous materials are used for thermal insulation, as scaffolds for nanocomposite manufacturing, and to capture fragrances, chemical catalysts and biochemicals. Nanodevices are electronic, optical, mechanical or elecromechanical products built on a nanosacle or with nanosized components. Other nanomaterials and nanotechnology products include nanofibers, nanowires, nanopowders, and nanopartiluates.

Nanomaterials and nanotechnology products are made of many different elements and compounds. Most nanocomposites consist of a matrix and a dispersed second phase in particulate, fibrous, or continuous form. This second phase may alter the nanomaterial’s electrical, thermal or magnetic properties; enhance its wear or erosion resistance; or serve as a strengthening or stiffening agent. Some nanomaterials and nanotechnology products are used as catalysts, colorants, filters, lubricants, membranes, and pigments. Others are used in biomaterial, chemical sensing, biomolecule tagging, magnetic storage, nanoelectronic, optoelectronic, photovoltaic, or structural applications. Nanomaterials and nanotechnology products that are designed or suitable for chemical-mechanical polishing (CMP) or single electron devices (SED) are also available.