|
Thiodiglycol
Thiodiglycol, or bis(2-hydroxyethyl)sulfide (also known as 2,2-thiodiethanol or TDE), is the organosulfur compound with the formula S(CH2CH2OH)2. It is miscible with water and polar organic solvents. It is a colorless liquid. It is structurally similar to diethylene glycol. Thiodiglycol is manufactured by reaction of 2-chloroethanol with sodium sulfide. Thiodiglycol is a polar protic solvent. It is used as a solvent in a variety of applications ranging from dyeing textiles to inks in some ballpoint pens. In chemical synthesis, it is used as a building block for protection products, dispersants, fibers, plasticizers, rubber accelerators, pesticides, dyes, and various other organic chemicals. In the manufacture of polymers, it is used as a chain transfer agent. As an antioxidant, it is used as an additive in lubricants. Thiodiglycol is used as a mounting medium in microscopy. The ability to vary the refractive index of the medium by varying the concentration of TDE in an aq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Schedule 2 Substances (CWC)
Schedule 2 substances, in the sense of the Chemical Weapons Convention, are chemicals that are feasible to use as chemical weapons themselves (Part A), or their manufacturing precursors (Part B), and which have small-scale applications outside of chemical warfare and so can be legitimately manufactured in small quantities. An example is thiodiglycol, which can be used in the manufacture of mustard agents but is also used as a solvent in inks. Manufacture must be declared as their production is subject to declaration to the Organisation for the Prohibition of Chemical Weapons (OPCW) per Part VII of the "Verification Annex", and they may not be exported to countries that are not party to the Convention. The Schedule 2 list is one of Schedules of substances annexed to the Chemical Weapons Convention, three lists. Chemicals that can be used as weapons, or used in their manufacture, but that have no, or almost no, legitimate applications as well are listed in List of Schedule 1 substan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bis(2-chloroethyl)sulfide
Bis(2-chloroethyl)sulfide is the organosulfur compound with the formula . It is a prominent member of a family of cytotoxic and blister agents known as mustard agents. Sometimes referred to as ''mustard gas'', the term is technically incorrect: bis(2-chloroethyl)sulfide is a liquid at room temperature. In warfare it was dispersed in the form of a fine mist of liquid droplets. Synthesis Bis(2-chloroethyl)sulfide has been prepared in a variety of ways. In the Depretz method, sulfur dichloride is treated with ethylene: : In the Levinstein process, disulfur dichloride is used instead: : + S8 In the Meyer method, thiodiglycol is produced from chloroethanol and sodium sulfide, and the resulting diol is then treated with phosphorus trichloride: : In the Meyer–Clarke method, concentrated hydrochloric acid (HCl) is used instead of PCl3: : Thionyl chloride and phosgene, the latter of which is also a choking agent, have also been used as chlorinating agents. These compounds ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MmHg
A millimetre of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high. Currently, it is defined as exactly , or approximately 1 torr = atmosphere = pascals.Council Directive 80/181/EEC of 20 December 1979 on the approximation of the laws of the Member States relating to units of measurement and on the repeal of Directive 71/354/EEC of the It is denoted mmHg or mm Hg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain Transfer Agent
In polymer chemistry, chain transfer is a polymerization reaction by which the activity of a growing polymer chain is transferred to another molecule: \ce^\bullet + \ce^\bullet where • is the active center, P is the initial polymer chain, X is the end group, and R is the substituent to which the active center is transferred. Chain transfer reactions reduce the average molecular weight of the final polymer. Chain transfer can be either introduced deliberately into a polymerization (by use of a ''chain transfer agent'') or it may be an unavoidable side-reaction with various components of the polymerization. Chain transfer reactions occur in most forms of addition polymerization including radical polymerization, ring-opening polymerization, coordination polymerization, and cationic polymerization, as well as anionic polymerization. Types Chain transfer reactions are usually categorized by the nature of the molecule that reacts with the growing chain. * Transfer to chain tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thioethers
In organic chemistry, a sulfide (British English sulphide) or thioether is an organosulfur functional group with the connectivity as shown on right. Like many other sulfur-containing compounds, volatile sulfides have foul odors. A sulfide is similar to an ether except that it contains a sulfur atom in place of the oxygen. The grouping of oxygen and sulfur in the periodic table suggests that the chemical properties of ethers and sulfides are somewhat similar, though the extent to which this is true in practice varies depending on the application. Nomenclature Sulfides are sometimes called thioethers, especially in the old literature. The two organic substituents are indicated by the prefixes. (CH3)2S is called dimethylsulfide. Some sulfides are named by modifying the common name for the corresponding ether. For example, C6H5SCH3 is methyl phenyl sulfide, but is more commonly called thioanisole, since its structure is related to that for anisole, C6H5OCH3. The modern systemati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvents
A solvent (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules, and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners (toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers (hexane, petrol ether); in detergents ( citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemical syntheses and purification processes Some petrochemical solvents are highly toxic and emit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urine
Urine is a liquid by-product of metabolism in humans and many other animals. In placental mammals, urine flows from the Kidney (vertebrates), kidneys through the ureters to the urinary bladder and exits the urethra through the penile meatus (males) or urethral meatus of the vulva (females) during urination. In other vertebrates, urine is excreted through the cloaca. Urine contains water-soluble by-products of Cell (biology), cellular metabolism that are rich in nitrogen and must be clearance (medicine), cleared from the Circulatory system, bloodstream, such as urea, uric acid and creatinine. A urinalysis can detect nitrogenous wastes of the mammalian body. Urine plays an important role in the earth's nitrogen cycle. In balanced ecosystems, urine fertilizes the soil and thus helps plants to grow. Therefore, Reuse of excreta, urine can be used as a fertilizer. Some animals use it to territory (animal)#Scent marking, mark their territories. Historically, aged or fermented urine (kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of Biomolecule, biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mustard Gas
Mustard gas or sulfur mustard are names commonly used for the organosulfur compound, organosulfur chemical compound bis(2-chloroethyl) sulfide, which has the chemical structure S(CH2CH2Cl)2, as well as other Chemical species, species. In the wider sense, compounds with the substituents are known as ''sulfur mustards'' or ''nitrogen mustards'', respectively, where X = Cl or Br. Such compounds are potent alkylating agents, making mustard gas acutely and severely toxic. Mustard gas is a carcinogen. There is no preventative agent against mustard gas, with protection depending entirely on skin and airways protection, and no antidote exists for mustard poisoning. Also known as mustard agents, this family of compounds comprises infamous cytotoxicity, cytotoxins and blister agents with a long history of use as chemical weapons. The name ''mustard gas'' is technically incorrect; the substances, when Dispersion (chemistry), dispersed, are often not gases but a fine mist of liquid droplet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Weapons Convention
The Chemical Weapons Convention (CWC), officially the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction, is an arms control treaty administered by the Organisation for the Prohibition of Chemical Weapons (OPCW), an intergovernmental organization based in The Hague, Netherlands. The treaty entered into force on 29 April 1997. It prohibits the use of chemical weapons, and the large-scale development, production, stockpiling, or transfer of chemical weapons or their precursors, except for very limited purposes (research, medical, pharmaceutical or protective). The main obligation of member states under the convention is to effect this prohibition, as well as the destruction of all current chemical weapons. All destruction activities must take place under OPCW verification. 193 states have become parties to the CWC and accept its obligations. Israel has signed but not ratified the agreement, while three o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractive Index
In optics, the refractive index (or refraction index) of an optical medium is the ratio of the apparent speed of light in the air or vacuum to the speed in the medium. The refractive index determines how much the path of light is bent, or refraction, refracted, when entering a material. This is described by Snell's law of refraction, , where and are the angle of incidence (optics), angle of incidence and angle of refraction, respectively, of a ray crossing the interface between two media with refractive indices and . The refractive indices also determine the amount of light that is reflectivity, reflected when reaching the interface, as well as the critical angle for total internal reflection, their intensity (Fresnel equations) and Brewster's angle. The refractive index, n, can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is , and similarly the wavelength in that me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microscopy
Microscopy is the technical field of using microscopes to view subjects too small to be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of microscopy: optical microscope, optical, electron microscope, electron, and scanning probe microscopy, along with the emerging field of X-ray microscopy. Optical microscopy and electron microscopy involve the diffraction, reflection (physics), reflection, or refraction of electromagnetic radiation/electron beams interacting with the Laboratory specimen, specimen, and the collection of the scattered radiation or another signal in order to create an image. This process may be carried out by wide-field irradiation of the sample (for example standard light microscopy and transmission electron microscope, transmission electron microscopy) or by scanning a fine beam over the sample (for example confocal laser scanning microscopy and scanning electron microscopy). Scan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
