Search Results - Amorphous
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An "amorphous solid" is a solid in which there is no long-range order of the positions of the atoms. (Solids in which there is long-range atomic order are called crystalline solids or morphous). Most classes of solid materials can be found or prepared in an amorphous form. For instance, common window glass is an amorphous solid, many polymers (such as polystyrene) are amorphous, and even foods such as cotton candy are amorphous solids. In principle, given a sufficiently high cooling rate, any liquid can be made into an amorphous solid. Cooling reduces molecular mobility. If the cooling rate is faster than the rate at which molecules can organize into a more thermodynamically favorable crystalline state, then an amorphous solid will be formed. Because of entropy considerations, many polymers can be made amorphous solids by cooling even at slow rates. In contrast, if molecules have sufficient time to organize into a structure with two- or three-dimensional order, then a crystalline (or semi-crystalline) solid will be formed. Water is one example. Because of its small molecular size and ability to quickly rearrange, it cannot be made amorphous without resorting to specialized hyperquenching techniques. Amorphous materials can also be produced by additives which interfere with the ability of the primary constituent to crystallize. For example, addition of soda to silicon dioxide results in window glass, and the addition of glycols to water results in a vitrified solid. Some materials, such as metals, are difficult to prepare in an amorphous state. Unless a material has a high melting temperature (as ceramics do) or a low crystallization energy (as polymers tend to), cooling must be done extremely rapidly. As the cooling is performed, the material changes from a supercooled liquid, with properties one would expect from a liquid state material, to a solid. The temperature at which this transition occurs is called the glass transition temperature or Tg.
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Showing 1 to 9 of 9 Articles matching 'Amorphous' in related articles. |
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1. Importance of Plastic Optical Fiber
March 05, 2010
Plastic is the general common term for a wide range of synthetic or semi synthetic organic amorphous solid materials used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce costs. Plastic optical fiber (POF) (or fibre) is an optical fiber which is made out of plastic. Traditionally PMMA (acrylic) is the core material, and fluorinated polymers are the cladding material. Since the late 1990s however, much higher-performance POF based on perfluorinated polymers (mainly polyperflu... (read more)
Author: Jayesh Khandor
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2. OMEGA Seamaster Planet Ocean Liquidmetal Limited Edition
February 07, 2010
OMEGA addicts, good news! OMEGA has announced the launch of the Seamaster Planet Ocean Liquidmetal Limited Edition, the world’s first watch to bond ceramics and Liquidmetal. The Liquidmetal alloy is an amorphous metal – a metallic material with a disordered, non-crystalline atomic structure. Its fusion temperature is half that of conventional titanium alloys but when it is cooled, its hardness is three times as great as that of stainless steel. Its amorphous structure allows it to bond seamlessly with the ceramic bezel.
OMEGA Seamaster Planet Ocean Liquidmetal timepiece will be a limited... (read more)
Author: Tommy Martin
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3. Who Is The Largest China Wholesale Jewelry Company?
January 24, 2010
Yiwu dushang jewelry company is In Yiwu city China,which has been largest online wholesale jewelry company with more than 30000 style of products in stock.Our products are all with good quality and very affordable price!
Now consumers and association in on the accomplished has amorphous to anticipate about added carefully their purchases and their impacts. The abridgement has afflicted the market, but so has amusing awareness. Now over ever, consumers are absorbed in area their purchases are advancing from and who they affect. Sometimes our purchases accept beyond implications and repercu... (read more)
Author: carl chen
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4. Uses for regular fiberglass
January 22, 2010
Glass fibers are useful because of their high ratio of surface area to weight. However, the increased surface area makes them much more susceptible to chemical attack. By trapping air within them, blocks of glass fiber make good thermal insulation, with a thermal conductivity of the order of 0.05 W/(m·K). The strength of glass is usually tested and reported for "virgin" or pristine fibers—those which have just been manufactured. The freshest, thinnest fibers are the strongest because the thinner fibers are more ductile. The more the surface is scratched, the less the resulting ... (read more)
Author: Simon suen
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5. Uses for regular fiberglass
January 22, 2010
Glass fibers are useful because of their high ratio of surface area to weight. However, the increased surface area makes them much more susceptible to chemical attack. By trapping air within them, blocks of glass fiber make good thermal insulation, with a thermal conductivity of the order of 0.05 W/(m·K). The strength of glass is usually tested and reported for "virgin" or pristine fibers—those which have just been manufactured. The freshest, thinnest fibers are the strongest because the thinner fibers are more ductile. The more the surface is scratched, the less the resulting ... (read more)
Author: simon suen
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6. Solar Power Future in Flexible Solar Panels
January 18, 2010
What are flexible solar panels? Flexible solar panels are very thin films of solar energy converting amorphous silicon cells that can be painted on items like plastic, which makes them very flexible.
The uniqueness of these cells comes from them being much smaller than regular silicon cell solar panels. Due to their flexibility, they can be used for a broader range of products than rigid cell panels, and they are definitely more portable. The drawback to flexible solar panels relates to the lower solar power conversion efficiency rates when compared to conventional solar cells.
Curre... (read more)
Author: Jakob Jelling
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7. Beijing Pinggu Solar Cell Projects
January 11, 2010
One on the 100 meters long black shiny "Yong Lu" in the foot extension, which consists of nearly ten thousand pieces paved amorphous silicon thin film solar plate, becoming the nation's largest rooftop solar power station. In June 2010, 150 megawatt amorphous silicon thin-film solar cell project will be in Beijing Pinggu all the green energy industry base built for Beijing to provide 220 million degrees per year of green electricity, equivalent to a 30-million people in the city's one-year electricity and to reduce carbon dioxide emissions of 150,000 tons, t... (read more)
Author: qing li
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8. Residential Solar Panels -- What you need to know
January 11, 2010
Residential solar panels consists of assemblies of solar panels mounted on the top someones home to use solar energy to make power. A solar panel is a set of photovoltaic cells arranged and packed in glass to capture sun's energy. Solar energy is one of the best renewable forms of energy, which is abundantly found in nature. This energy can be later used for several domestic purposes such as: cooking, generating electricity, and heating watermaking electricity, heating water, or even cooking} etc. Some of the solar panels which can be used for residential purposes are polycrystalline solar pan... (read more)
Author: Joshua Vadney
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9. Experience innovation in floor designing with ceramic tiles
January 07, 2010
A step on ceramic tile is a step onto centuries of history of tile development and manufacture. A ceramic is an inorganic, non metallic solid prepared by the action of heat followed by cooling. Ceramic materials may have a crystalline structure or may be amorphous. The earliest ceramics were pottery objects made from clay or clay mixed with other materials. Ceramics is now widely used for building domestic, industrial, residential structures and art objects.
Homeowners are using various tile designs in their living room, dining rooms, bathroom, kitchen, toilet rooms, roof, sun rooms and ... (read more)
Author: Thomasan Adison
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