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Nanostructure
A nanostructure is a structure of intermediate size between microscopic and molecular structures. Nanostructural detail is microstructure at nanoscale. In describing nanostructures, it is necessary to differentiate between the number of dimensions in the volume of an object which are on the nanoscale. Nanotextured surfaces have ''one dimension'' on the nanoscale, i.e., only the thickness of the surface of an object is between 0.1 and 100 nm. Nanotubes have ''two dimensions'' on the nanoscale, i.e., the diameter of the tube is between 0.1 and 100 nm; its length can be far more. Finally, spherical nanoparticles have ''three dimensions'' on the nanoscale, i.e., the particle is between 0.1 and 100 nm in each spatial dimension. The terms nanoparticles and ultrafine particles (UFP) are often used synonymously although UFP can reach into the micrometre range. The term ''nanostructure'' is often used when referring to magnetic technology. Nanoscale structure in biology i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanoring
A nanoring is a cyclic nanostructure with a thickness small enough to be on the nanoscale (10−9 meters). Note that this definition allows the diameter of the ring to be larger than the nanoscale. Nanorings are a relatively recent development within the realm of nanoscience; the first peer-reviewed journal article mentioning these nanostructures came from researchers at the Institute of Physics and Center for Condensed Matter Physics in Beijing who synthesized nanorings made of gallium nitride in 2001. Zinc oxide, a compound very commonly used in nanostructures, was first synthesized into nanorings by researchers at Georgia Institute of Technology in 2004 and several other common nanostructure compounds have been synthesized into nanorings since. More recently, carbon-based nanorings have been synthesized from cyclo-para-phenylenes as well as porphyrins. Overview Although nanorings may have a diameter on the nanoscale, many of these materials have diameters which are larger than 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanocomposite
Nanocomposite is a multiphase solid material where one of the phases has one, two or three dimensions of less than 100 nanometers (nm) or structures having nano-scale repeat distances between the different phases that make up the material. The idea behind Nanocomposite is to use building blocks with dimensions in nanometre range to design and create new materials with unprecedented flexibility and improvement in their physical properties. In the broadest sense this definition can include porous media, colloids, gels and copolymers, but is more usually taken to mean the solid combination of a bulk matrix and nano-dimensional phase(s) differing in properties due to dissimilarities in structure and chemistry. The mechanical, electrical, thermal, optical, electrochemical, catalytic properties of the nanocomposite will differ markedly from that of the component materials. Size limits for these effects have been proposed: in Kelly, A, ''Concise encyclopedia of composites materials'', El ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gradient Multilayer Nanofilm
Gradient multilayer (GML) nanofilm is an assembly of quantum dot layers with a built-in gradient of nanoparticle size, composition or density. Properties of such nanostructure are finding its applications in design of solar cells and energy storage devices. The GML nanostructure can be embedded in the organic material (polymer), or can include quantum dots made of two or more types of material. Photovoltaic applications The GML nanofilm only 100 nanometers thick can absorb the entire Sun spectrum (0.3–2.0+ eV). At the same time, gradient of the quantum dots size can create a gradient of the electrochemical potential, acting as an equivalent of built-in electric field inside a nanofilm. This enhances transport of electrons and holes, and improves internal quantum efficiency (IQE) and photocurrent. Manufacturing The industrial manufacturing of GML nanofilms represents a challenge. Traditional methods of building nanostructured materials (like spin coating) can't form GML n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanopillar
Nanopillars is an emerging technology within the field of nanostructures. Nanopillars are pillar shaped nanostructures approximately 10 nanometers in diameter that can be grouped together in lattice like arrays. They are a type of metamaterial, which means that nanopillars get their attributes from being grouped into artificially designed structures and not their natural properties. Nanopillars set themselves apart from other nanostructures due to their unique shape. Each nanopillar has a pillar shape at the bottom and a tapered pointy end on top. This shape in combination with nanopillars' ability to be grouped together exhibits many useful properties. Nanopillars have many applications including efficient solar panels, high resolution analysis, and antibacterial surfaces. Applications Solar panels Due to their tapered ends, nanopillars are very efficient at capturing light. Solar collector surfaces coated with nanopillars are three times as efficient as nanowire solar cells. L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanomesh
The nanomesh is an inorganic nanostructured two-dimensional material, similar to graphene. It was discovered in 2003 at the University of Zurich, Switzerland. It consists of a single layer of boron (B) and nitrogen (N) atoms, which forms by self-assembly into a highly regular mesh after high-temperature exposure of a clean rhodium or ruthenium surface to borazine under ultra-high vacuum. The nanomesh looks like an assembly of hexagonal poresIn the literature different words referring to similar concepts can be found. Below is a summary of them: * ''Pores, apertures, holes:'' areas of the nanomesh laying the closest to the underlying substrate due to a strong attraction. They form depressions, which are 0.05 nm deep and have a hexagonal shape. * ''Wires:'' areas of the nanomesh referring to the border of the pores, which lay the farer away to the underlying substrate and therefore represent the upper part of the nanomesh. (see right image) at the nanometer (nm) scale. The distance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanoparticle
A nanoparticle or ultrafine particle is usually defined as a particle of matter that is between 1 and 100 nanometres (nm) in diameter. The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 100 nm in only two directions. At the lowest range, metal particles smaller than 1 nm are usually called atom clusters instead. Nanoparticles are usually distinguished from microparticles (1-1000 µm), "fine particles" (sized between 100 and 2500 nm), and "coarse particles" (ranging from 2500 to 10,000 nm), because their smaller size drives very different physical or chemical properties, like colloidal properties and ultrafast optical effects or electric properties. Being more subject to the brownian motion, they usually do not sediment, like colloidal particles that conversely are usually understood to range from 1 to 1000 nm. Being much smaller than the wavelengths of visible light (400-700 nm), nano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanoparticle
A nanoparticle or ultrafine particle is usually defined as a particle of matter that is between 1 and 100 nanometres (nm) in diameter. The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 100 nm in only two directions. At the lowest range, metal particles smaller than 1 nm are usually called atom clusters instead. Nanoparticles are usually distinguished from microparticles (1-1000 µm), "fine particles" (sized between 100 and 2500 nm), and "coarse particles" (ranging from 2500 to 10,000 nm), because their smaller size drives very different physical or chemical properties, like colloidal properties and ultrafast optical effects or electric properties. Being more subject to the brownian motion, they usually do not sediment, like colloidal particles that conversely are usually understood to range from 1 to 1000 nm. Being much smaller than the wavelengths of visible light (400-700 nm), nano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanofiber
Nanofibers are fibers with diameters in the nanometer range (typically, between 1 nm and 1 μm). Nanofibers can be generated from different polymers and hence have different physical properties and application potentials. Examples of natural polymers include collagen, cellulose, silk fibroin, keratin, gelatin and polysaccharides such as chitosan and alginate. Examples of synthetic polymers include poly(lactic acid) (PLA), polycaprolactone (PCL), polyurethane (PU), poly(lactic-co-glycolic acid) (PLGA), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and poly(ethylene-co-vinylacetate) (PEVA). Polymer chains are connected via covalent bonds. The diameters of nanofibers depend on the type of polymer used and the method of production. All polymer nanofibers are unique for their large surface area-to-volume ratio, high porosity, appreciable mechanical strength, and flexibility in functionalization compared to their microfiber counterparts. There exist many different methods to mak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microstructure
Microstructure is the very small scale structure of a material, defined as the structure of a prepared surface of material as revealed by an optical microscope above 25× magnification. The microstructure of a material (such as metals, polymers, ceramics or composites) can strongly influence physical properties such as strength, toughness, ductility, hardness, corrosion resistance, high/low temperature behaviour or wear resistance. These properties in turn govern the application of these materials in industrial practice. Microstructure at scales smaller than can be viewed with optical microscopes is often called nanostructure, while the structure in which individual atoms are arranged is known as crystal structure. The nanostructure of biological specimens is referred to as ultrastructure. A microstructure’s influence on the mechanical and physical properties of a material is primarily governed by the different defects present or absent of the structure. These defects can tak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanotextured Surface
A nanotextured surface (NTS) is a surface which is covered with nano-sized structures. Such surfaces have one dimension on the nanoscale, i.e., only the thickness of the surface of an object is between 0.1 and 100 nm. They are currently gaining popularity because of their special applications due to their unique physical properties. Nanotextured surfaces are in various forms like cones, columns, or fibers. These are water, ice, oil, and microorganism repellent that is superamphiphobic, anti-icing, and antifouling respectively and thus self-cleaning. They are simultaneously anti-reflective and transparent, hence they are termed ''smart'' surfaces. In research published online October 21, 2013, in Advanced Materials, of a group of scientists at the U.S. Department of Energy's Brookhaven National Laboratory (BNL), led by BNL physicist and lead author Antonio Checco, proposed that nanotexturing surfaces in the form of cones produces highly water-repellent surfaces. These nano-cone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultrafine Particle
Ultrafine particles (UFPs) are particulate matter of nanoscale size (less than 0.1 μm or 100 nm in diameter). Regulations do not exist for this size class of ambient air pollution particles, which are far smaller than the regulated PM10 and PM2.5 particle classes and are believed to have several more aggressive health implications than those classes of larger particulates. In the EU UFP's in ambient air are empirically defined by technical specification The important detail is the definition of size, stated: "The lower and upper sizes considered within this document are 7 nm and a few micrometres, respectively". Although the most common referral to UFP is "less than 0.1μm", this is incorrect for ambient air in the EU. There are two main divisions that categorize types of UFPs. UFPs can either be carbon-based or metallic, and then can be further subdivided by their magnetic properties. Electron microscopy and special physical lab conditions allow scientists to observe UFP mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Icosahedral Twins
An icosahedral twin is a nanostructure appearing for atomic clusters and also nanoparticles with some thousands of atoms. These clusters are twenty-faced, made of twenty interlinked tetrahedra crystals, typically joined along triangular (e.g. cubic-(111)) faces having three-fold symmetry. One can think of their formation as a kind of atom-scale self-assembly. A related, more common structure has five units similarly arranged with twinning, which were known as "fivelings" in the 19th centuryH. Hofmeister (2004) "Fivefold twinned nanoparticles" in ''Encyclopedia of Nanoscience and Nanotechnology'' (ed. H. S. Nalwa, Amer. Sci. Publ., Stevenson Ranch CA) vol. 3, pp. 431-452pdf, more recently as "decahedral multiply twinned particles", "pentagonal particles" or "star particles". A variety of different methods (e.g. condensing argon, metal atoms, and virus capsids) lead to icosahedral form at size scales where surface energies are more important those from the bulk. Causes Wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
