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Phthalocyanine Blue
Copper phthalocyanine (CuPc), also called phthalocyanine blue, phthalo blue and many other names, is a bright, crystalline, synthetic blue pigment from the group of phthalocyanine dyes. Its brilliant blue is frequently used in paints and dyes. It is highly valued for its superior properties such as light fastness, tinting strength, covering power and resistance to the effects of alkalis and acids. It has the appearance of a blue powder, insoluble in most solvents including water. History The discovery of metal phthalocyanines can be traced to the observation of intensely colored byproducts from reactions of phthalic acid (benzene-1,2-dicarboxylic acid) or its derivatives with sources of nitrogen and metals. CuPc (copper phthalocyanine) was first prepared in 1927 by the reaction of copper(I) cyanide and ''o''-dibromobenzene, which mainly produces colorless phthalonitrile as well as an intensely blue by-product. A couple of years later, workers at Scottish Dyes observed the form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper Phthalocyanine Powder
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form (native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create bronze, c. 350 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rutile
Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer Polymorphism (materials science), polymorphs of TiO2 are known, including anatase, akaogiite, and brookite. Rutile has one of the highest refractive index, refractive indices at visible wavelengths of any known crystal and also exhibits a particularly large birefringence and high dispersion (optics), dispersion. Owing to these properties, it is useful for the manufacture of certain optical elements, especially Polarization (waves), polarization optics, for longer light, visible and infrared, infrared wavelengths up to about 4.5 micrometres. Natural rutile may contain up to 10% iron and significant amounts of niobium and tantalum. Rutile derives its name from the Latin ('red'), in reference to the deep red color observed in some specimens when viewed by transmitted light. Rutile was first described in 1803 by Abraham Gottlob Werner. Occurrence Rutile is a common accessory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Stability
In chemistry, chemical stability is the thermodynamic stability of a chemical system. Thermodynamic stability occurs when a system is in its lowest energy state, or in chemical equilibrium with its environment. This may be a dynamic equilibrium in which individual atoms or molecules change form, but their overall number in a particular form is conserved. This type of chemical thermodynamic equilibrium will persist indefinitely unless the system is changed. Chemical systems might undergo changes in the phase of matter or a set of chemical reactions. State A is said to be more thermodynamically stable than state B if the Gibbs free energy of the change from A to B is positive. Versus reactivity Thermodynamic stability applies to a particular system. The reactivity of a chemical substance is a description of how it might react across a variety of potential chemical systems and, for a given system, how fast such a reaction could proceed. Chemical substances or states can persis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Solar Cell
An organic solar cell (OSC) or plastic solar cell is a type of photovoltaic that uses organic electronics, a branch of electronics that deals with conductive organic polymers or small organic molecules, for light absorption and charge transport to produce electricity from sunlight by the photovoltaic effect. Most organic photovoltaic cells are polymer solar cells. The molecules used in organic solar cells are solution-processable at high throughput and are cheap, resulting in low production costs to fabricate a large volume. Combined with the flexibility of organic molecules, organic solar cells are potentially cost-effective for photovoltaic applications. Molecular engineering (''e.g.,'' changing the length and functional group of polymers) can change the band gap, allowing for electronic tunability. The optical absorption coefficient of organic molecules is high, so a large amount of light can be absorbed with a small amount of materials, usually on the order of hundreds of nan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Electronics
Molecular electronics is the study and application of molecular building blocks for the fabrication of electronic components. It is an interdisciplinary area that spans physics, chemistry, and materials science. The unifying feature is use of molecular building blocks to fabricate electronic components. Due to the prospect of size reduction in electronics offered by molecular-level control of properties, molecular electronics has generated much excitement. It provides a potential means to extend Moore's Law beyond the foreseen limits of small-scale conventional silicon integrated circuits. Molecular scale electronics Molecular scale electronics, also called single-molecule electronics, is a branch of nanotechnology that uses single molecules, or nanoscale collections of single molecules, as electronic components. Because single molecules constitute the smallest stable structures possible, this miniaturization is the ultimate goal for shrinking electrical circuits. Convention ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastic
Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptability, plus a wide range of other properties, such as being lightweight, durable, flexible, and inexpensive to produce, has led to its widespread use. Plastics typically are made through human industrial systems. Most modern plastics are derived from fossil fuel-based chemicals like natural gas or petroleum; however, recent industrial methods use variants made from renewable materials, such as corn or cotton derivatives. 9.2 billion tonnes of plastic are estimated to have been made between 1950 and 2017. More than half this plastic has been produced since 2004. In 2020, 400 million tonnes of plastic were produced. If global trends on plastic demand continue, it is estimated that by 2050 annual global plastic production will reach over 1, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Sulfide
Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The underground mine gas term for foul-smelling hydrogen sulfide-rich gas mixtures is ''stinkdamp''. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777. The British English spelling of this compound is hydrogen sulphide, a spelling no longer recommended by the Royal Society of Chemistry or the International Union of Pure and Applied Chemistry. Hydrogen sulfide is toxic to humans and most other animals by inhibiting cellular respiration in a manner similar to hydrogen cyanide. When it is inhaled or it or its salts are ingested in high amounts, damage to organs occurs rapidly with symptoms ranging from breathing difficulties to convulsions and death. Despite this, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen Reduction Reaction
In chemistry, the oxygen reduction reaction refers to the reduction half reaction whereby O2 is reduced to water or hydrogen peroxide. In fuel cells, the reduction to water is preferred because the current is higher. The oxygen reduction reaction is well demonstrated and highly efficient in nature. Stoichiometry The stoichiometries of the oxygen reduction reaction, which depends on the medium, are shown: 4e− pathway in acid medium: O2 + 4 e- + 4H+ -> 2 H2O 2e− pathway in acid medium: O2 + 2e- + 2H+ -> H2O2 4e− pathway in alkaline medium: O2 + 4e- + 2H2O -> 4 OH- 2e− pathway in alkaline medium: O2 + 2e- + H2O -> HO2- + OH- 4e- pathway in solid oxide: O2 + 4e- -> 2 O^2- The 4e− pathway reaction is the cathode reaction in fuel cell especially in proton-exchange membrane fuel cells, alkaline fuel cell and solid oxide fuel cell. While the 2e− pathway reaction is often the side reaction of 4e- pathway or can be used in synthesis of H2O2. Catalysts Biocatalysts The oxyg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper(I) Chloride
Copper(I) chloride, commonly called cuprous chloride, is the lower chloride of copper, with the formula CuCl. The substance is a white solid sparingly soluble in water, but very soluble in concentrated hydrochloric acid. Impure samples appear green due to the presence of copper(II) chloride (CuCl2). History Copper(I) chloride was first prepared by Robert Boyle in the mid-seventeenth century from mercury(II) chloride ("Venetian sublimate") and copper metal: :HgCl2 + 2 Cu → 2 CuCl + Hg In 1799, J.L. Proust characterized the two different chlorides of copper. He prepared CuCl by heating CuCl2 at red heat in the absence of air, causing it to lose half of its combined chlorine followed by removing residual CuCl2 by washing with water. An acidic solution of CuCl was formerly used for analysis of carbon monoxide content in gases, for example in Hempel's gas apparatus. This application was significant during the nineteenth and early twentieth centuries when coal gas was widely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urea
Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid. Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals. It is a colorless, odorless solid, highly soluble in water, and practically non-toxic ( is 15 g/kg for rats). Dissolved in water, it is neither acidic nor alkaline. The body uses it in many processes, most notably nitrogen excretion. The liver forms it by combining two ammonia molecules () with a carbon dioxide () molecule in the urea cycle. Urea is widely used in fertilizers as a source of nitrogen (N) and is an important raw material for the chemical industry. In 1828 Friedrich Wöhler discovered that urea can be produced from inorganic starting materials, which was an important conceptual milestone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Rail
British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four British railway companies, and was privatised in stages between 1994 and 1997. Originally a trading brand of the Railway Executive of the British Transport Commission, it became an independent statutory corporation in January 1963, when it was formally renamed the British Railways Board. The period of nationalisation saw sweeping changes in the railway. A process of dieselisation and electrification took place, and by 1968 steam locomotives had been entirely replaced by diesel and electric traction, except for the Vale of Rheidol Railway (a narrow-gauge tourist line). Passengers replaced freight as the main source of business, and one-third of the network was closed by the Beeching cuts of the 1960s in an effort to reduce rail subsidies. On privatis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colour Index International
Colour Index International is a reference database jointly maintained by the Society of Dyers and Colourists and the American Association of Textile Chemists and Colorists. It currently contains over 27,000 individual products listed under 13,000 Colour Index Generic Names. It was first printed in 1925 but is now published solely on the World Wide Web. The index serves as a common reference database of manufactured colour products and is used by manufacturers and consumers, such as artists and decorators. Colorants (both dyes and pigments) are listed using a dual classification which use the Colour Index Generic Name (the prime identifier) and Colour Index Constitution Numbers. These numbers are prefixed with C.I. or CI, for example, C.I. 15510. (This abbreviation is sometimes mistakenly thought to be CL, due to the font used to display it.) A detailed record of products available on the market is presented under each Colour Index reference. For each product name, Colour Index I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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