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Ground Glass Joint
Ground glass joints are used in laboratories to quickly and easily fit leak-tight apparatus together from interchangeable commonly available parts. For example, a round bottom flask, Liebig condenser, and oil bubbler with ground glass joints may be rapidly fitted together to reflux a reaction mixture. This is a large improvement compared with older methods of custom-made glassware, which was time-consuming and expensive, or the use of less chemical resistant and heat resistant corks or rubber bungs and glass tubes as joints, which took time to prepare as well. One of the glassware items to be joined would have an ''inner'' (or male) ''joint'' with the ground glass surface facing outward and the other would have an ''outer'' (or female) ''joint'' of a correspondingly fitting taper with the ground glass surface facing inward. To connect the hollow inner spaces of the glassware components, ground glass joints are hollow on the inside and open at the ends, except for stoppers. His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Round Bottom Flask
Round-bottom flasks (also called round-bottomed flasks or RB flasks) are types of flasks having spherical bottoms used as laboratory glassware, mostly for chemical or biochemical work. They are typically made of glass for chemical inertness; and in modern days, they are usually made of heat-resistant borosilicate glass. There is at least one tubular section known as the ''neck'' with an opening at the tip. Two- or three-necked flasks are common as well. Round bottom flasks come in many sizes, from 5 mL to 20 L, with the sizes usually inscribed on the glass. In pilot plants even larger flasks are encountered. The ends of the necks are usually conical ground glass joints. These are standardized, and can accept any similarly-sized tapered (male) fittings. 24/20 is common for 250 mL or larger flasks, while smaller sizes such as 14/20 or 19/22 are used for smaller flasks. Because of the round bottom, cork rings are needed to keep the round bottom flasks upright. W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laboratory Glassware
Laboratory glassware refers to a variety of equipment used in scientific work, and traditionally made of glass. Glass can be blown, bent, cut, molded, and formed into many sizes and shapes, and is therefore common in chemistry, biology, and analytical laboratories. Many laboratories have training programs to demonstrate how glassware is used and to alert first–time users to the safety hazards involved with using glassware. History Ancient era The history of glassware dates back to the Phoenicians who fused obsidian together in campfires making the first glassware. Glassware evolved as other ancient civilizations including the Syrians, Egyptians, and Romans refined the art of glassmaking. Mary the Jewess, an alchemist in Alexandria during the 1st century AD, is credited for the creation of some of the first glassware for chemical such as the ''kerotakis'' which was used for the collection of fumes from a heated material. Despite these creations, glassware for chemical us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfluoroisobutylene
Perfluoroisobutene (PFIB) is the perfluorocarbon counterpart of the hydrocarbon isobutene and has the formula (CF3)2C=CF2. An alkene, it is a colorless gas that is notable as a highly toxic perfluoroalkene. Few simple alkenes are as toxic. Safety Perfluoroisobutene is quite toxic with an LCt = 880 mg⋅min⋅m−3 (mice). It is a Schedule 2 substance of the Chemical Weapons Convention. Perfluoroisobutene is highly reactive toward nucleophiles. It hydrolyzes readily to give the relatively innocuous (CF3)2CHCO2H, which readily decarboxylates to give hexafluoropropane. It forms addition compounds with thiols, and it is this reactivity that may be related to its toxicity. PFIB is a product of pyrolysis of polytetrafluoroethylene (PTFE), one of the substances invoked to explain polymer fume fever. External links International Chemical Safety Card 1216 See also *Phosgene *Bis(trifluoromethyl) disulfide Bis(trifluoromethyl) disulfide (TFD) is a fluorinated organosulfur comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyacetal
Polyoxymethylene (POM), also known as acetal, polyacetal, and polyformaldehyde, is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability. As with many other synthetic polymers, it is produced by different chemical firms with slightly different formulas and sold variously by such names as Delrin, Kocetal, Ultraform, Celcon, Ramtal, Duracon, Kepital, Polypenco, Tenac and Hostaform. POM is characterized by its high strength, hardness and rigidity to −40 °C. POM is intrinsically opaque white because of its high crystalline composition but can be produced in a variety of colors. POM has a density of 1.410–1.420g/cm3. Typical applications for injection-molded POM include high-performance engineering components such as small gear wheels, eyeglass frames, ball bearings, ski bindings, fasteners, gun parts, knife handles, and lock systems. The material is widely used in the automotive and consumer electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Keck
Hermann Keck (1919 – 2010) was a German scientist who invented the Keck Clip. Keck was born in Treysa Treysa, an independent town until 1970, is the biggest ''Stadtteil'' of the German town Schwalmstadt. It was incorporated into Schwalmstadt in December 1970. The location around Treysa and Schwalmstadt is called Schwalm. The historic city lie ... and has two patents on his name: * Clip for fixing male and female parts of ground glass joints, (1984). * Handled clamp for ground glass ball and socket joints or the like, (1988).Design patent References {{DEFAULTSORT:Keck, Hermann 20th-century German chemists 1919 births 2010 deaths People from Schwalmstadt 20th-century German inventors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keck Clips
Ground glass joints are used in laboratories to quickly and easily fit leak-tight apparatus together from interchangeable commonly available parts. For example, a round bottom flask, Liebig condenser, and oil bubbler with ground glass joints may be rapidly fitted together to reflux a reaction mixture. This is a large improvement compared with older methods of custom-made glassware, which was time-consuming and expensive, or the use of less chemical resistant and heat resistant corks or rubber bungs and glass tubes as joints, which took time to prepare as well. One of the glassware items to be joined would have an ''inner'' (or male) ''joint'' with the ground glass surface facing outward and the other would have an ''outer'' (or female) ''joint'' of a correspondingly fitting taper with the ground glass surface facing inward. To connect the hollow inner spaces of the glassware components, ground glass joints are hollow on the inside and open at the ends, except for stoppers. His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toluene With Sodium-benzophenone
Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon. It is a colorless, water-insoluble liquid with the smell associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH3) attached to a phenyl group. As such, its systematic IUPAC name is methylbenzene. Toluene is predominantly used as an industrial feedstock and a solvent. As the solvent in some types of paint thinner, permanent markers, contact cement and certain types of glue, toluene is sometimes used as a recreational inhalant and has the potential of causing severe neurological harm. History The compound was first isolated in 1837 through a distillation of pine oil by the Polish chemist Filip Walter, who named it ''rétinnaphte''. In 1841, French chemist Henri Étienne Sainte-Claire Deville isolated a hydrocarbon from balsam of Tolu (an aromatic extract from the tropical Colombian tree ''Myroxylon balsamum''), which Deville recognized as similar to Wal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lab Keck
Lab most often refers to: * Laboratory, a facility to conduct scientific research Lab or LAB may also refer to: Places * Láb, a village near Bratislava in western Slovakia * Lab (river), in north-eastern Kosovo People * ISO 639 code for the ancient Minoan language of Crete Music * LAB Records, a British independent record label * LAB (band), a Finnish band * L.A.B., a New Zealand reggae band Transportation * Linhas Aéreas Brasileiras, a defunct Brazilian airline * Lloyd Aéreo Boliviano, a defunct Bolivian airline * League of American Bicyclists Science and technology * Linear alkylbenzene * Lithosphere-Asthenosphere boundary, between layers of the Earth * Lactic acid bacteria * Lab color space * Lyman-alpha blob, in interstellar space * Linear alkylbenzene sulfonate Groups * Langile Abertzaleen Batzordeak, a Basque trade union * Lockerz advisory board * Los Angeles Baptist High School, US Other * Labrador Retriever, a dog breed * Legs, abs, and butt fitness workout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diazomethane
Diazomethane is the chemical compound CH2N2, discovered by German chemist Hans von Pechmann in 1894. It is the simplest diazo compound. In the pure form at room temperature, it is an extremely sensitive explosive yellow gas; thus, it is almost universally used as a solution in diethyl ether. The compound is a popular methylating agent in the laboratory, but it is too hazardous to be employed on an industrial scale without special precautions. Use of diazomethane has been significantly reduced by the introduction of the safer and equivalent reagent trimethylsilyldiazomethane. Use For safety and convenience diazomethane is always prepared as needed as a solution in ether and used as such. It converts carboxylic acids to methyl esters and phenols into their methyl ethers. The reaction is thought to proceed via proton transfer from carboxylic acid to diazomethane to give methyldiazonium cation, which reacts with the carboxylate ion to give the methyl ester and nitrogen gas. Label ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syringe
A syringe is a simple reciprocating pump consisting of a plunger (though in modern syringes, it is actually a piston) that fits tightly within a cylindrical tube called a barrel. The plunger can be linearly pulled and pushed along the inside of the tube, allowing the syringe to take in and expel liquid or gas through a discharge orifice at the front (open) end of the tube. The open end of the syringe may be fitted with a hypodermic needle, a nozzle or tubing to direct the flow into and out of the barrel. Syringes are frequently used in clinical medicine to administer injections, infuse intravenous therapy into the bloodstream, apply compounds such as glue or lubricant, and draw/measure liquids. There are also prefilled syringes (disposable syringes marketed with liquid inside). The word "syringe" is derived from the Greek σύριγξ ('' syrinx'', meaning "Pan flute", "tube"). Medical syringes Sectors in the syringe and needle market include disposable and safe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luer Taper
The Luer taper is a standardized system of small-scale fluid fittings used for making leak-free connections between a male-taper fitting and its mating female part on medical and laboratory instruments, including hypodermic syringe tips and needles or stopcocks and needles. Currently ISO 80369 governs the Luer standards and testing methods. History Named after the Lüer-family who founded the medical instrument maker Maison Lüer in Paris, the two piece syringe invented by either the employed instrument maker Karl Schneider or Jeanne Lüer together with the glass blower Fournier, it was patented by Jeanne's husband Hermann Wülfing Lüer in 1894, with international patents taken out the following years. It originated as a 6% taper fitting for glass bottle stoppers (so one side is at 1.72 degrees to the centerline). Key features of Luer taper connectors are defined in the ISO 594 standards. It is also defined in the DIN and EN standard 1707:1996 and 20594-1:1993. In 1930, Fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
