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Bleaching
Bleach is the generic name for any chemical product that is used industrially or domestically to remove color from (i.e. to whiten) fabric or fiber (in a process called bleaching) or to disinfect after cleaning. It often refers specifically to a dilute solution of sodium hypochlorite, also called "liquid bleach". Many bleaches have broad-spectrum bactericidal properties, making them useful for disinfecting and sterilizing. They are used in swimming pool sanitation to control bacteria, viruses, and algae and in many places where sterile conditions are required. They are also used in many industrial processes, notably in the bleaching of wood pulp. Bleaches also have other minor uses, like removing mildew, killing weeds, and increasing the longevity of cut flowers. Bleaches work by reacting with many colored organic compounds, such as natural pigments, and turning them into colorless ones. While most bleaches are oxidizing agents (chemicals that can remove electrons from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bleaching Of Wood Pulp
Bleaching of wood pulp is the chemical processing of wood pulp to lighten its color and whiten the pulp. The primary product of wood pulp is paper, for which whiteness (similar to, but distinct from brightness) is an important characteristic. These processes and chemistry are also applicable to the bleaching of non-wood pulps, such as those made from bamboo or kenaf. Paper brightness Brightness is the amount of incident light reflected from paper under specified conditions, usually reported as the percentage of light reflected, so a higher number means a brighter or whiter paper. In the US, the TAPPI T 452 or T 525 standards are used. The international community uses ISO standards. The table shows how the two systems rate high-brightness papers, but there is no simple way to convert between the two systems because the test methods are so different. The ISO rating is higher and can be over 100. This is because contemporary white paper incorporates fluorescent whiten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen Bleach
Bleach is the generic name for any chemical product that is used industrially or domestically to remove color from (i.e. to whiten) fabric or fiber (in a process called bleaching) or to disinfect after cleaning. It often refers specifically to a dilute solution of sodium hypochlorite, also called "liquid bleach". Many bleaches have broad-spectrum bactericidal properties, making them useful for disinfecting and sterilizing. They are used in swimming pool sanitation to control bacteria, viruses, and algae and in many places where sterile conditions are required. They are also used in many industrial processes, notably in the bleaching of wood pulp. Bleaches also have other minor uses, like removing mildew, killing weeds, and increasing the longevity of cut flowers. Bleaches work by reacting with many colored organic compounds, such as natural pigments, and turning them into colorless ones. While most bleaches are oxidizing agents (chemicals that can remove electrons from other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscosity, viscous than Properties of water, water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%–6% by weight) in water for consumer use and in higher concentrations for industrial use. Concentrated hydrogen peroxide, or "high-test peroxide", decomposes explosively when heated and has been used as both a monopropellant and an oxidizer in rocketry. Hydrogen peroxide is a reactive oxygen species and the simplest peroxide, a compound having an oxygen–oxygen single bond. It decomposes slowly into water and elemental oxygen when exposed to light, and rapidly in the presence of organic or reactive compounds. It is typically stored with a Stabilizer (chemistry), stabilizer in a weakly acidic solution in an opaque bottle. Hydrogen peroxide is found in biological systems including the human body. Enzymes that u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorine
Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidizing agent, oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the revised Electronegativity#Pauling electronegativity, Pauling scale, behind only oxygen and fluorine. Chlorine played an important role in the experiments conducted by medieval Alchemy, alchemists, which commonly involved the heating of chloride Salt (chemistry), salts like ammonium chloride (sal ammoniac) and sodium chloride (common salt), producing various chemical substances containing chlorine such as hydrogen chloride, mercury(II) chloride (corrosive sublimate), and . However, the nature of fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypochlorite
In chemistry, hypochlorite, or chloroxide is an oxyanion with the chemical formula ClO−. It combines with a number of cations to form hypochlorite salts. Common examples include sodium hypochlorite (household bleach) and calcium hypochlorite (a component of bleaching powder, swimming pool "chlorine"). The Cl–O distance in ClO− is 1.69 Å. The name can also refer to esters of hypochlorous acid, namely organic compounds with a ClO– group covalently bound to the rest of the molecule. The principal example is ''tert''-butyl hypochlorite, which is a useful chlorinating agent. Most hypochlorite salts are handled as aqueous solutions. Their primary applications are as bleaching, disinfection, and water treatment agents. They are also used in chemistry for chlorination and oxidation reactions. Reactions Acid reaction Acidification of hypochlorites generates hypochlorous acid, which exists in an equilibrium with chlorine. A lowered pH (i.e. towards acid) drives the fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Hypochlorite
Sodium hypochlorite is an alkaline inorganic chemical compound with the formula (also written as NaClO). It is commonly known in a dilute aqueous solution as bleach or chlorine bleach. It is the sodium salt of hypochlorous acid, consisting of sodium cations () and hypochlorite anions (, also written as and ). The anhydrous compound is unstable and may decompose explosively. It can be crystallized as a pentahydrate , a pale greenish-yellow solid which is not explosive and is stable if kept refrigerated. Sodium hypochlorite is most often encountered as a pale greenish-yellow dilute solution referred to as chlorine bleach, which is a household chemical widely used (since the 18th century) as a disinfectant and bleaching agent. In solution, the compound is unstable and easily decomposes, liberating chlorine, which is the active principle of such products. Sodium hypochlorite is still the most important chlorine-based bleach. Its corrosive properties, common availability, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfuric Acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula . It is a colorless, odorless, and Viscosity, viscous liquid that is Miscibility, miscible with water. Pure sulfuric acid does not occur naturally due to its Dehydration reaction, strong affinity to water vapor; it is Hygroscopy, hygroscopic and readily absorbs water vapor from the Atmosphere of Earth, air. Concentrated sulfuric acid is a strong oxidant with powerful dehydrating properties, making it highly corrosive towards other materials, from rocks to metals. Phosphorus pentoxide is a notable exception in that it is not dehydrated by sulfuric acid but, to the contrary, dehydrates sulfuric acid to sulfur trioxide. Upon addition of sulfuric acid to water, a considerable amount of heat is releas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bleachfield
A bleachfield or bleaching green was an open area used for spreading cloth on the ground to be purified and whitened by the action of the sunlight. Bleaching fields were usually found in and around mill towns in Great Britain and were an integral part of textile manufacture during the British Industrial Revolution. When cloth-making was still a home-based occupation, the bleachfields could be found on Scottish Croft (land), crofts and English farm Field (agriculture), fields. Just as wool needed fulling and flax needed retting, so did the semi-finished fabrics need space and time outdoors to bleach. In the 18th century there were many linen bleachfields in Scotland, particularly in Perthshire, Renfrewshire (historic), Renfrewshire, in the Scottish Lowlands, and the outskirts of Glasgow#History, Glasgow. By the 1760s, linen manufacture became a major industry in Scotland, second only to agriculture. For instance, in 1782 alone, Perthshire produced of linen, worth £81,000 (£ as of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur Dioxide
Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is released naturally by volcanic activity and is produced as a by-product of metals refining and the burning of Sour gas, sulfur-Sour crude oil, bearing fossil fuels. Sulfur dioxide is somewhat toxic to humans, although only when inhaled in relatively large quantities for a period of several minutes or more. It was known to medieval alchemy, alchemists as "volatile spirit of sulfur". Structure and bonding SO2 is a bent molecule with ''C''2v Point groups in three dimensions, symmetry point group. A valence bond theory approach considering just ''s'' and ''p'' orbitals would describe the bonding in terms of resonance (chemistry), resonance between two resonance structures. The sulfur–oxygen bond has a bond order of 1.5. There is support f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Perborate
Sodium perborate are chemical compounds with chemical formula (H2O)x. Commonly encountered salts are the anhydrous form (x = 0) and as a hydrate, hexahydrate (x = 6). These two species are sometimes called, respectively, "monohydrate" or PBS-1 and "tetrahydrate" or PBS-4, after the historic assumption that would be the anhydrous form). Both the anhydrous and hexahydrate salts are white, odorless, water-soluble solids. Peroxyborates are widely used in laundry detergents, as one of the peroxide-based bleaches. Sodium perborate was first obtained in 1898, independently, by Sebastian Tanatar and by P. Melikoff and L. Pissadewsky; the researchers prepared sodium perborate by treating sodium borate with a solution of hydrogen peroxide and sodium hydroxide, but Tanatar also obtained sodium perborate by electrolysis of a solution of sodium borate. Structure Unlike sodium percarbonate, the peroxyborates are not adducts of hydrogen peroxide. Rather, they contain a peroxyborate anion , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Hypochlorite
Calcium hypochlorite is an inorganic compound with chemical formula , also written as . It is a white solid, although commercial samples appear yellow. It strongly smells of chlorine, owing to its slow decomposition in moist air. This compound is relatively stable as a solid and solution and has greater available chlorine than sodium hypochlorite. "Pure" samples have 99.2% active chlorine. Given common industrial purity, an active chlorine content of 65-70% is typical. It is the main active ingredient of commercial products called bleaching powder, used for water treatment and as a bleaching agent. History Charles Tennant and Charles Macintosh developed an industrial process in the late 18th century for the manufacture of chloride of lime, patenting it in 1799. Tennant's process is essentially still used today, and became of military importance during World War I, because calcium hypochlorite was the active ingredient in trench disinfectant. Uses Sanitation Calcium hypochlor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Wilhelm Scheele
Carl Wilhelm Scheele (, ; 9 December 1742 – 21 May 1786) was a Swedish Pomerania, German-Swedish pharmaceutical chemist. Scheele discovered oxygen (although Joseph Priestley published his findings first), and identified the elements molybdenum, tungsten, barium, nitrogen, and chlorine, among others. Scheele discovered organic acids Tartaric acid, tartaric, Oxalic acid, oxalic, Uric acid, uric, Lactic acid, lactic, and Citric acid, citric, as well as Hydrofluoric acid, hydrofluoric, Hydrocyanic acid, hydrocyanic, and Arsenic acid, arsenic acids. He preferred speaking German to Swedish his whole life, as German was commonly spoken among Swedish pharmacists.Fors, Hjalmar 2008. "Stepping through Science’s Door: C. W. Scheele, from Pharmacist's Apprentice to Man of Science". Ambix 55: 29–49 Biography Scheele was born in Stralsund, in western Pomerania, which at the time was a Dominions of Sweden, Swedish Dominion inside the Holy Roman Empire. Scheele's father, Joachim (or Jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
