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Vinylcarbazole
''N''-Vinylcarbazole is an organic compound used as a monomer in the production of poly(vinylcarbazole), a conductive polymer, in which conductivity is photon-dependent. The benzine compound is used in the photoreceptors of photocopiers. Upon exposure to ''γ''-irradiation, ''N''-vinylcarbazole undergoes solid-state polymerisation. It is produced by the vinylation of carbazole with acetylene in the presence of base. Related compounds *Carbazole Carbazole is an aromatic Heterocyclic compound, heterocyclic organic compound. It has a tricyclic structure, consisting of two six-membered benzene rings fused on either side of a five-membered nitrogen-containing ring. The compound's structure is ... References {{DEFAULTSORT:Vinylcarbazole, N- Carbazoles Monomers Vinyl compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Poly-(N-vinyl Carbazole)
Polyvinylcarbazole (PVK) is a temperature-resistantHans-Dieter Jakubke, Ruth Karcher (Koordinatoren): ''Lexikon der Chemie'' in drei Bänden, Spektrum Verlag, Band 3, Heidelberg 1999, , S. 92. thermoplastic polymer produced by radical polymerization from the monomer N-Vinylcarbazole, ''N''-vinylcarbazole. It is a photoconductive polymer and thus the basis for Photorefractive effect, photorefractive polymers and organic light-emitting diodes.. History Polyvinylcarbazole was discovered by the chemists Walter Reppe (1892-1969), Ernst Keyssner and Eugen Dorrer and patented by IG Farben, I.G. Farben in the USA in 1937.US-Patent Nr. 2,072,46pdfpiw.uspto.gov ''Production of polymeric N-Vinyl compounds.'' Priorität 24. Juli 1934, veröffentlicht am 2. März 1937, Anmelder: I.G. Farbenindustrie Aktiengesellschaft, Erfinder: Walter Reppe, Ernst Keyssner, Eugen Dorrer. PVK was the first polymer whose photoconductivity was known. Starting in the 1960s, further polymers of this kind were so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Photoconductivity
Photoconductivity is an optical and electrical phenomenon in which a material becomes more electrically conductive due to the absorption of electromagnetic radiation such as visible light, ultraviolet light, infrared light, or gamma radiation. When light is absorbed by a material such as a semiconductor, the number of free electrons and holes increases, resulting in increased electrical conductivity. To cause excitation, the light that strikes the semiconductor must have enough energy to raise electrons across the band gap, or to excite the impurities within the band gap. When a bias voltage and a load resistor are used in series with the semiconductor, a voltage drop across the load resistors can be measured when the change in electrical conductivity of the material varies the current through the circuit. Classic examples of photoconductive materials include: * photographic film: Kodachrome, Fujifilm, Agfachrome, Ilford, ''etc.'', based on silver sulfide and silver bromi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Carbazole
Carbazole is an aromatic Heterocyclic compound, heterocyclic organic compound. It has a tricyclic structure, consisting of two six-membered benzene rings fused on either side of a five-membered nitrogen-containing ring. The compound's structure is based on the indole structure, but in which a second benzene ring is fused onto the five-membered ring at the 2–3 position of indole (equivalent to the 9a–4a double bond in carbazole, respectively). Carbazole is a constituent of tobacco smoke. History Carl Graebe and Carl Andreas Glaser, Carl Glaser first isolated the compound from coal tar in 1872. Production Few carbazole production methods are economically viable, due to limited demand. During coal tar distillation, carbazole concentrates in the anthracene distillate and must be removed before anthraquinone production; that waste product is the major industrial carbazole source. Polar compounds (e.g., ketones) selectively precipitate it from the anthracene; a more modern techn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
CRC Press
The CRC Press, LLC is an American publishing group that specializes in producing technical books. Many of their books relate to engineering, science and mathematics. Their scope also includes books on business, forensics and information technology. CRC Press is now a division of Taylor & Francis, itself a subsidiary of Informa. History The CRC Press was founded as the Chemical Rubber Company (CRC) in 1903 by brothers Arthur, Leo and Emanuel Friedman in Cleveland, Ohio, based on an earlier enterprise by Arthur, who had begun selling rubber laboratory aprons in 1900. The company gradually expanded to include sales of laboratory equipment to chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a graduated scientist trained in the study of chemistry, or an officially enrolled student in the field. Chemists study the composition of ...s. In 1913 the CRC offered a short (116-page) manual called the ''Rubber Handboo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Diethyl Ether
Diethyl ether, or simply ether, is an organic compound with the chemical formula , sometimes abbreviated as . It is a colourless, highly Volatility (chemistry), volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It belongs to the ether class of organic compounds. It is a common solvent and was formerly used as a general anesthetic. Production Most diethyl ether is produced as a byproduct of the vapor-phase Hydration reaction, hydration of ethylene to make ethanol. This process uses solid-supported phosphoric acid Catalysis, catalysts and can be adjusted to make more ether if the need arises: Vapor-phase Dehydration reaction, dehydration of ethanol over some Aluminium oxide, alumina catalysts can give diethyl ether yields of up to 95%. : Diethyl ether can be prepared both in laboratories and on an industrial scale by the acid ether synthesis. Uses The dominant use of diethyl ether is as a solvent. One particular application is in the production of cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Organic Compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-containing compounds such as alkanes (e.g. methane ) and its derivatives are universally considered organic, but many others are sometimes considered inorganic, such as certain compounds of carbon with nitrogen and oxygen (e.g. cyanide ion , hydrogen cyanide , chloroformic acid , carbon dioxide , and carbonate ion ). Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, and even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Società Chimica Italiana
The Italian Chemical Society () is the national association in Italy representing the chemical sciences. Its main aim is to promote and support the development of chemistry and scientific research, spreading the knowledge of chemistry and its applications in order to improve the welfare of the country, establishing and maintaining relations with organizations from other countries with similar purposes and promoting the study of this subject at school and university. History The Italian Chemical Society was formed in 1909 by the union of two existing societies, the Chemical Society of Rome, founded in 1902, and the Chemical Society of Milan, founded in 1895. The two original societies became sections of the new one and a third section was added in 1910, when the Chemical Society of Naples was incorporated. During the First World War, the activity of the society experienced a marked decrease and the link among the three sections got was loosened, with the result that, in 1919, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Conductive Polymer
Conductive polymers or, more precisely, intrinsically conducting polymers (ICPs) are organic polymers that conduct electricity. Such compounds may have metallic conductivity or can be semiconductors. The main advantage of conductive polymers is that they are easy to process, mainly by dispersion. Conductive polymers are generally not thermoplastics, ''i.e.'', they are not thermoformable. But, like insulating polymers, they are organic materials. They can offer high electrical conductivity but do not show similar mechanical properties to other commercially available polymers. The electrical properties can be fine-tuned using the methods of organic synthesis and by advanced dispersion techniques. History Polyaniline was first described in the mid-19th century by Henry Letheby, who investigated the electrochemical and chemical oxidation products of aniline in acidic media. He noted that the reduced form was colourless but the oxidized forms were deep blue. The first highly-con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Xerography
Xerography is a dry photocopying technique. Originally called electrophotography, it was renamed xerography—from the Greek roots , meaning "dry" and , meaning "writing"—to emphasize that unlike reproduction techniques then in use such as cyanotype, the process of xerography used no liquid chemicals. History Xerography was invented by American physicist Chester Carlson, based significantly on contributions by Hungarian physicist Pál Selényi. Carlson applied for and was awarded on October 6, 1942. Carlson's innovation combined electrostatic printing with photography, unlike the dry electrostatic printing process invented by Georg Christoph Lichtenberg in 1778. Carlson's original process was cumbersome, requiring several manual processing steps with flat plates. In 1946, Carlson signed an agreement with Haloid Photographic Company to develop it as a commercial product. Before that year, Carlson had proposed his idea to more than a dozen companies, but none was int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Heinemann (book Publisher)
William Heinemann Ltd., with the imprint Heinemann, was a London-based publisher founded in 1890 by William Heinemann. Their first published book, 1890's The Bondman (novel), ''The Bondman'', was a huge success in the United Kingdom and launched the company. He was joined in 1893 by Sydney Pawling. Heinemann died in 1920 and Pawling sold the company to Doubleday (publisher), Doubleday, having worked with them in the past to publish their works in the United States. Pawling died in 1922 and new management took over. Doubleday sold his interest in 1933. Through the 1920s, the company was well known for publishing works by famous authors that had previously been published as Serial (literature), serials. Among these were works by H. G. Wells, Rudyard Kipling, W. Somerset Maugham, George Moore (novelist), George Moore, Max Beerbohm and Henry James, among others. This attracted new authors to publish their first editions with the company, including Graham Greene, Edward Upward, J. B. Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Gamma Ray
A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays. With frequencies above 30 exahertz () and wavelengths less than 10 picometers (), gamma ray photons have the highest photon energy of any form of electromagnetic radiation. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium. In 1903, Ernest Rutherford named this radiation ''gamma rays'' based on their relatively strong penetration of matter; in 1900, he had already named two less penetrating types of decay radiation (discovered by Henri Becquerel) alpha rays and beta rays in ascending order of penetrating power. Gamma rays from radioactive decay are in the energy range ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
