Carbon monofluoride (CF, CFx, or (CF)x), also called polycarbon monofluoride (PMF), polycarbon fluoride, poly(carbon monofluoride), and graphite fluoride, is a material formed by high-temperature reaction of fluorine gas with graphite, charcoal, or pyrolytic carbon powder. It is a highly hydrophobic microcrystalline powder. Its CAS number is . In contrast to graphite intercalation compounds it is a covalent graphite compound.
Carbon is stable in a fluorine atmosphere up to about 400 °C, but between 420-600 °C a reaction takes place to give substoichiometric carbon monofluoride, CF0.68 appearing dark grey. With increasing temperature and fluorine pressure stoichiometries up to CF1.12 are formed. With increasing fluorine content the colour changes from dark grey to cream white indicating the loss of the aromatic character. The fluorine atoms are located in an alternating fashion above and under the former graphene plane, which is now buckled due to formation of covalent carbon-fluorine bonds. Reaction of carbon with fluorine at even higher temperature successively destroys the graphite compound to yield a mixture of gaseous fluorocarbons such as tetrafluorocarbon, CF4, and tetrafluoroethylene, C2F4.
A precursor of carbon monofluoride is the fluorine-graphite intercalation compound, also called fluorine-GIC.
Other intercalation fluorides of carbon are
Carbon monofluoride is used as a high-energy-density cathode material in lithium batteries of the "BR" type. Other uses are a wear reduction additive for lubricants, and weather-resistant additive for paints. Graphite fluoride is also used as both oxidizing agent and combustion modifier in rocket propellants and pyrolants.
Carbon monofluoride is commercially available as Carbofluor-brand materials.
Standard battery nomenclature describes portable dry cell batteries that have physical dimensions and electrical characteristics interchangeable between manufacturers. The long history of disposable dry cells means that many different manufacturer-specific and national standards were used to designate sizes, long before international standards were reached. Technical standards for battery sizes and types are set by standards organizations such as International Electrotechnical Commission (IEC) and American National Standards Institute (ANSI). Popular sizes are still referred to by old standard or manufacturer designations, and some non-systematic designations have been included in current international standards due to wide use.
The complete nomenclature for the battery will fully specify the size, chemistry, terminal arrangements and special characteristics of a battery. The same physically interchangeable cell size may have widely different characteristics; physical interchangeability is not the sole factor in substitution of batteries.
National standards for dry cell batteries have been developed by ANSI, JIS, British national standards, and others. Civilian, commercial, government and military standards all exist. Two of the most prevalent standards currently in use are the IEC 60086 series and the ANSI C18.1 series. Both standards give dimensions, standard performance characteristics, and safety information.
Modern standards contain both systematic names for cell types that give information on the composition and approximate size of the cells, as well as arbitrary numeric codes for cell size.Button cell
A watch battery or button cell is a small single cell battery shaped as a squat cylinder typically 5 to 25 mm (0.197 to 0.984 in) in diameter and 1 to 6 mm (0.039 to 0.236 in) high — resembling a button. A metal can forms the bottom body and positive terminal of the cell. An insulated top cap is the negative terminal.
Button cells are used to power small portable electronics devices such as wrist watches, pocket calculators, artificial cardiac pacemakers, implantable cardiac defibrillators, automobile keyless entry transmitters, and hearing aids. Wider variants are usually called coin cells. Devices using button cells are usually designed around a cell giving a long service life, typically well over a year in continuous use in a wristwatch. Most button cells have low self-discharge and hold their charge for a long time if not used. Relatively high-power devices such as hearing aids may use a zinc–air battery which have much higher capacity for a given size, but dry out after a few weeks even if not used.
Button cells are single cells, usually disposable primary cells. Common anode materials are zinc or lithium. Common cathode materials are manganese dioxide, silver oxide, carbon monofluoride, cupric oxide or oxygen from the air. Mercuric oxide button cells were formerly common, but are no longer available due to the toxicity and environmental effects of mercury.
Cells of different chemical composition made in the same size are mechanically interchangeable. However, the composition can affect service life and voltage stability. Using the wrong cell may lead to short life or improper operation (for example, light metering on a camera requires a stable voltage, and silver cells are usually specified). Sometimes different cells of the same type and size and specified capacity in milliampere-hour (mAh) are optimised for different loads by using different electrolytes, so that one may have longer service life than the other if supplying a relatively high current.
Button cells are very dangerous for small children. Button cells that are swallowed can cause severe internal burns and significant injury or death.David K. Lam
David K. Lam (Chinese: 林杰屏; pinyin: Lín Jiépíng; Jyutping: Lam4 Git6ping4) is a Chinese-born American technology entrepreneur. He founded Lam Research Corporation in 1980. He presently serves as Chairman of Multibeam Corporation (Santa Clara, CA), which manufactures complementary electron beam lithography (CEBL) systems. He also heads the David Lam Group, an investor and business advisor for high-growth technology companies.Fluorine
Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. As the most electronegative element, it is extremely reactive, as it reacts with almost all other elements, except for helium and neon.
Among the elements, fluorine ranks 24th in universal abundance and 13th in terrestrial abundance. Fluorite, the primary mineral source of fluorine which gave the element its name, was first described in 1529; as it was added to metal ores to lower their melting points for smelting, the Latin verb fluo meaning "flow" gave the mineral its name. Proposed as an element in 1810, fluorine proved difficult and dangerous to separate from its compounds, and several early experimenters died or sustained injuries from their attempts. Only in 1886 did French chemist Henri Moissan isolate elemental fluorine using low-temperature electrolysis, a process still employed for modern production. Industrial production of fluorine gas for uranium enrichment, its largest application, began during the Manhattan Project in World War II.
Owing to the expense of refining pure fluorine, most commercial applications use fluorine compounds, with about half of mined fluorite used in steelmaking. The rest of the fluorite is converted into corrosive hydrogen fluoride en route to various organic fluorides, or into cryolite, which plays a key role in aluminium refining. Molecules containing a carbon–fluorine bond often have very high chemical and thermal stability; their major uses are as refrigerants, electrical insulation and cookware, the last as PTFE (Teflon). Pharmaceuticals such as atorvastatin and fluoxetine contain C-F bonds. The fluoride ion from dissolved fluoride salts inhibits dental cavities, and so finds use in toothpaste and water fluoridation. Global fluorochemical sales amount to more than US$15 billion a year.
Fluorocarbon gases are generally greenhouse gases with global-warming potentials 100 to 23 500 times that of carbon dioxide, SF6 having the highest global warming potential of any known substance. Organofluorine compounds often persist in the environment due to the strength of the carbon–fluorine bond. Fluorine has no known metabolic role in mammals; a few plants and sea sponges synthesize organofluorine poisons (most often monofluoroacetates) that help deter predation.Fluorographene
Fluorographene (or perfluorographane, graphene fluoride) is a fluorocarbon derivative of graphene. It is a two dimensional carbon sheet of sp3 hybridized carbons, with each carbon atom bound to one fluorine. The chemical formula is (CF)n. In comparison, Teflon (polytetrafluoroethylene), -(CF2)n-, consists of carbon "chains" with each carbon bound to two fluorines.
Unlike fluorographene, graphene is unsaturated (sp2 hybridized) and completely carbon. The hydrocarbon analogue to fluorographene is sp3 hybridized graphane. Similar to other fluorocarbons (e.g. perfluorohexane), fluorographene is highly insulating. Fluorographene is thermally stable, resembling polytetrafluoroethylene; however, chemically it is reactive. It can be transformed back into graphene by reaction with KI under higher temperature. During reactions of fluorographene with NaOH and NaSH simultaneous reductive defluorination and substitution are observed. The reactivity of fluorographene represents a facile way towards graphene derivatives.Fluoromethylidyne
Fluoromethylidyne is not a stable chemical species but a metastable radical containing one highly reactive carbon atom bound to one fluorine atom with the formula CF. The carbon atom has a lone-pair and a single unpaired (radical) electron in the ground state.Ground-state fluoromethylidyne radicals can be produced by the ultraviolet photodissociation of dibromodifluoromethane at 248 nanometer wavelength.It readily and irreversibly dimerises to difluoroacetylene, also known as difluoroethyne, perfluoroacetylene, or di- or perfluoroethylyne. Under certain conditions it can hexamerise to hexafluorobenzene.Graphite intercalation compound
Graphite intercalation compounds (GICs) are complex materials having a formula CXm where the ion Xn+ or Xn− is inserted (intercalated) between the oppositely charged carbon layers. Typically m is much less than 1. These materials are deeply colored solids that exhibit a range of electrical and redox properties of potential applications.List of battery sizes
This article lists the sizes, shapes, and general characteristics of some common primary and secondary battery types in household and light industrial use.
Historically the term "battery" referred to a collection of electrochemical cells connected in series, however in modern times the term has come to refer to any collection of cells (or single cell) packaged in a container with external connections provided to power electrical devices, leading to the variety of standardized form factors available today.
The long history of disposable dry cells means that many different manufacturer-specific and national standards were used to designate sizes, long before international standards were agreed upon. Technical standards for battery sizes and types are published by standards organizations such as the International Electrotechnical Commission (IEC) and American National Standards Institute (ANSI). Many popular sizes are still referred to by old standard or manufacturer designations, and some non-systematic designations have been included in current international standards due to wide use.
The complete nomenclature for a battery specifies size, chemistry, terminal arrangement, and special characteristics. The same physically interchangeable cell size or battery size may have widely different characteristics; physical interchangeability is not the sole factor in substituting a battery.Lithium battery
Lithium batteries are primary batteries that have metallic lithium as an anode. These types of batteries are also referred to as lithium-metal batteries.
They stand apart from other batteries in their high charge density (long life) and high cost per unit. Depending on the design and chemical compounds used, lithium cells can produce voltages from 1.5 V (comparable to a zinc–carbon or alkaline battery) to about 3.7 V.
Disposable primary lithium batteries must be distinguished from secondary lithium-ion or a lithium-polymer, which are rechargeable batteries. Lithium is especially useful, because its ions can be arranged to move between the anode and the cathode, using an intercalated lithium compound as the cathode material but without using lithium metal as the anode material. Pure lithium will instantly react with water, or even moisture in the air; the lithium in lithium ion batteries is in a less reactive compound.
Lithium batteries are widely used in portable consumer electronic devices, and in electric vehicles ranging from full sized vehicles to radio controlled toys. The term "lithium battery" refers to a family of different lithium-metal chemistries, comprising many types of cathodes and electrolytes but all with metallic lithium as the anode. The battery requires from 0.15 to 0.3 kg of lithium per kWh. As designed these primary systems use a charged cathode, that being an electro-active material with crystallographic vacancies that are filled gradually during discharge.
The most common type of lithium cell used in consumer applications uses metallic lithium as anode and manganese dioxide as cathode, with a salt of lithium dissolved in an organic solvent.Monofluoride
A monofluoride is a chemical compound with one fluoride per formula unit. For a binary compound, this is the formula XF.PMF
PMF may stand for:
Pacific Music Festival, an international classical music festival held annually in Sapporo, Japan
Paramilitary forces, a semi-militarized force
Private military firm, a private company providing armed combat or security services for financial gain.
Parma Airport, Italy (IATA airport code)
Peptide mass fingerprinting, an analytical technique for protein identification
Pierre Mendès France (1907–1982), Prime Minister of France
Polarization-maintaining optical fiber, a type of optical fiber
Polycarbon monofluoride, a graphite compound with fluorine; also known as carbon monofluoride
Popular Mobilization Forces (Iraq), an Iraqi state-sponsored umbrella organization
Potential of mean force, in chemistry, potential giving the average force on a particle from a set of molecules
Presidential Management Fellows Program, a US government fellowship
Primary myelofibrosis, a disease affecting the bone marrow.
Probability mass function, in statistics, function giving the probability that a variable takes a particular value
Product/market fit, in marketing, the degree to which a product satisfies a strong market demand
Professional Medical Film, a U.S. Army designation
Progressive massive fibrosis, an interstitial lung disease complication often seen in silicosis and pneumoconiosis
Proton motive force, a measure of energy in biological reactions
PMF - Hacker turned Federal informant Operation CybersnarePyrolant
A pyrolant (from Greek pyr, fire) is an energetic material that generates hot flames upon combustion. Pyrolants are metal-based pyrotechnic compositions containing virtually any oxidizer.
The term was originally coined by Kuwahara in 1992, in a paper on magnesium/Teflon/Viton, to distinguish between compositions that serve as propellants and those yielding hot flames which are not necessarily suitable for propellant purposes.
Thermites constitute a subdivision of pyrolants referring to mixtures containing a narrow range of oxygen-based oxidizers only, Hence the term thermite cannot be used interchangeably with "pyrolant".
A similar common term is propellant, which describes either a homogeneous or composite material that generates thrust upon combustion, but which may contain fuels instead of or in addition to the metals contained in thermites.
Pyrolants are generally characterized by high combustion temperatures (> 2000 K) and high amounts of condensed reaction products at equilibrium conditions such as metal oxides, fluorides and soot.
Typical pyrolants find use as pyrotechnic initiators (Zr/BaCrO4 or Zr/KClO4), illuminating flare (Mg/NaNO3) and decoy flare compositions (Mg/(C2F4)n)Russell P. Hughes
Russell P. Hughes (born December 23, 1946) an American/British chemist, is the Frank R. Mori Professor Emeritus and Research Professor in the Department of Chemistry at Dartmouth College. His research interests are in organometallic chemistry, with emphasis on the chemistry of transition metal interacting with fluorocarbons. His work in this area led to several creative syntheses of complexes between metal complexes and perfluorinated hydrocarbon fragments.Ultralife Corporation
Ultralife Corporation (NASDAQ: ULBI) designs and manufactures batteries and communications systems worldwide. Ultralife serves government and defense, medical, safety and security, energy, robotics and other customers across the globe through the design and development of a range of products. Founded in 1991 and headquartered in Newark, New York, the Company’s business segments include battery and energy products and communications systems.
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