Sulfur hexafluoride

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Sulfur hexafluoride
Skeletal formula of sulfur hexafluoride with assorted dimensions Sulfur-hexafluoride-2D-dimensions.png
Skeletal formula of sulfur hexafluoride with assorted dimensions
Spacefill model of sulfur hexafluoride Sulfur-hexafluoride-3D-vdW.png
Spacefill model of sulfur hexafluoride
Sulfur-hexafluoride-3D-balls.png
Names
IUPAC name
Sulfur hexafluoride
Systematic IUPAC name
Hexafluoro-λ6-sulfane [1]
Other names
Elagas

Esaflon
Sulfur(VI) fluoride

Sulfuric fluoride
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.018.050 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 219-854-2
2752
KEGG
MeSH Sulfur+hexafluoride
PubChem CID
RTECS number
  • WS4900000
UNII
UN number 1080
  • InChI=1S/F6S/c1-7(2,3,4,5)6 Yes check.svgY
    Key: SFZCNBIFKDRMGX-UHFFFAOYSA-N Yes check.svgY
  • FS(F)(F)(F)(F)F
Properties
SF6
Molar mass 146.05 g·mol−1
AppearanceColorless gas
Odor odorless [2]
Density 6.17 g/L
Melting point −64 °C; −83 °F; 209 K
Boiling point −50.8 °C (−59.4 °F; 222.3 K)
Critical point (T, P)45.51±0.1 °C, 3.749±0.01 MPa [3]
0.003% (25 °C) [2]
Solubility slightly soluble in water, very soluble in ethanol, hexane, benzene
Vapor pressure 2.9 MPa (at 21.1 °C)
−44.0×10−6 cm3/mol
Thermal conductivity
  • 13.45 mW/(m·K) at 25 °C [4]
  • 11.42 mW/(m·K) at 0 °C
Viscosity 15.23 μPa·s [5]
Structure
Orthorhombic, oP28
Oh
Orthogonal hexagonal
Octahedral
0 D
Thermochemistry
0.097 kJ/(mol·K) (constant pressure)
Std molar
entropy (S⦵298)
292 J·mol−1·K−1 [6]
−1209 kJ·mol−1 [6]
Pharmacology
V08DA05 ( WHO )
License data
Hazards
GHS labelling: [7]
GHS-pictogram-bottle.svg
Warning
H280
P403
NFPA 704 (fire diamond)
NFPA 704.svgHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazard SA: Simple asphyxiant gas. E.g. nitrogen, helium
1
0
0
SA
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 1000 ppm (6000 mg/m3) [2]
REL (Recommended)
TWA 1000 ppm (6000 mg/m3) [2]
IDLH (Immediate danger)
N.D. [2]
Safety data sheet (SDS) External MSDS
Related compounds
Related sulfur fluorides
 Disulfur decafluoride

Sulfur tetrafluoride

Related compounds
 Selenium hexafluoride

Sulfuryl fluoride
Tellurium hexafluoride
Polonium hexafluoride

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Sulfur hexafluoride or sulphur hexafluoride (British spelling) is an inorganic compound with the formula SF6. It is a colorless, odorless, non-flammable, and non-toxic gas. SF
6 has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a hypervalent molecule.

Typical for a nonpolar gas, SF
6 is poorly soluble in water but quite soluble in nonpolar organic solvents. It has a density of 6.12 g/L at sea level conditions, considerably higher than the density of air (1.225 g/L). It is generally transported as a liquefied compressed gas.

SF
6 has 23,500 times greater global warming potential (GWP) than CO2 as a greenhouse gas (over a 100-year time-frame) but exists in relatively minor concentrations in the atmosphere. Its concentration in Earth's troposphere reached 11.50 parts per trillion (ppt) in October 2023, rising at 0.37 ppt/year. [8] The increase since 1980 is driven in large part by the expanding electric power sector, including fugitive emissions from banks of SF
6 gas contained in its medium- and high-voltage switchgear. Uses in magnesium, aluminium, and electronics manufacturing also hastened atmospheric growth. [9]

Synthesis and reactions

Sulfur hexafluoride on Earth exists primarily as a synthetic industrial gas, but has also been found to occur naturally. [10]

SF
6 can be prepared from the elements through exposure of S
8 to F
2. This was also the method used by the discoverers Henri Moissan and Paul Lebeau in 1901. Some other sulfur fluorides are cogenerated, but these are removed by heating the mixture to disproportionate any S
2F
10 (which is highly toxic) and then scrubbing the product with NaOH to destroy remaining SF
4.

Alternatively, using bromine, sulfur hexafluoride can be synthesized from SF4 and CoF3 at lower temperatures (e.g. 100 °C), as follows: [11]

2 CoF3 + SF4 + [Br2] → SF6 + 2 CoF2 + [Br2]

There is virtually no reaction chemistry for SF
6. A main contribution to the inertness of SF6 is the steric hindrance of the sulfur atom, whereas its heavier group 16 counterparts, such as SeF6 are more reactive than SF6 as a result of less steric hindrance. [12] It does not react with molten sodium below its boiling point, [13] but reacts exothermically with lithium. As a result of its inertness, SF
6 has an atmospheric lifetime of around 3200 years, and no significant environmental sinks other than the ocean. [14]

Applications

By 2000, the electrical power industry is estimated to use about 80% of the sulfur hexafluoride produced, mostly as a gaseous dielectric medium. [15] Other main uses as of 2015 included a silicon etchant for semiconductor manufacturing, and an inert gas for the casting of magnesium. [16]

Dielectric medium

SF
6 is used in the electrical industry as a gaseous dielectric medium for high-voltage sulfur hexafluoride circuit breakers, switchgear, and other electrical equipment, often replacing oil-filled circuit breakers (OCBs) that can contain harmful polychlorinated biphenyls (PCBs). SF
6 gas under pressure is used as an insulator in gas insulated switchgear (GIS) because it has a much higher dielectric strength than air or dry nitrogen. The high dielectric strength is a result of the gas's high electronegativity and density. This property makes it possible to significantly reduce the size of electrical gear. This makes GIS more suitable for certain purposes such as indoor placement, as opposed to air-insulated electrical gear, which takes up considerably more room.

Gas-insulated electrical gear is also more resistant to the effects of pollution and climate, as well as being more reliable in long-term operation because of its controlled operating environment. Exposure to an arc chemically breaks down SF
6 though most of the decomposition products tend to quickly re-form SF
6, a process termed "self-healing". [17] Arcing or corona can produce disulfur decafluoride (S
2F
10), a highly toxic gas, with toxicity similar to phosgene. S
2F
10 was considered a potential chemical warfare agent in World War II because it does not produce lacrimation or skin irritation, thus providing little warning of exposure.

SF
6 is also commonly encountered as a high voltage dielectric in the high voltage supplies of particle accelerators, such as Van de Graaff generators and Pelletrons and high voltage transmission electron microscopes.

Alternatives to SF
6 as a dielectric gas include several fluoroketones. [18] [19] Compact GIS technology that combines vacuum switching with clean air insulation has been introduced for a subset of applications up to 420  kV. [20]

Medical use

SF
6 is used to provide a tamponade or plug of a retinal hole in retinal detachment repair operations [21] in the form of a gas bubble. It is inert in the vitreous chamber. [22] The bubble initially doubles its volume in 36 hours due to oxygen and nitrogen entering it, before being absorbed in the blood in 10–14 days. [23]

SF
6 is used as a contrast agent for ultrasound imaging. Sulfur hexafluoride microbubbles are administered in solution through injection into a peripheral vein. These microbubbles enhance the visibility of blood vessels to ultrasound. This application has been used to examine the vascularity of tumours. [24] It remains visible in the blood for 3 to 8 minutes, and is exhaled by the lungs. [25]

Tracer compound

Sulfur hexafluoride was the tracer gas used in the first roadway air dispersion model calibration; this research program was sponsored by the U.S. Environmental Protection Agency and conducted in Sunnyvale, California on U.S. Highway 101. [26] Gaseous SF
6 is used as a tracer gas in short-term experiments of ventilation efficiency in buildings and indoor enclosures, and for determining infiltration rates. Two major factors recommend its use: its concentration can be measured with satisfactory accuracy at very low concentrations, and the Earth's atmosphere has a negligible concentration of SF
6.

Sulfur hexafluoride was used as a non-toxic test gas in an experiment at St John's Wood tube station in London, United Kingdom on 25 March 2007. [27] The gas was released throughout the station, and monitored as it drifted around. The purpose of the experiment, which had been announced earlier in March by the Secretary of State for Transport Douglas Alexander, was to investigate how toxic gas might spread throughout London Underground stations and buildings during a terrorist attack.

Sulfur hexafluoride is also routinely used as a tracer gas in laboratory fume hood containment testing. The gas is used in the final stage of ASHRAE 110 fume hood qualification. A plume of gas is generated inside of the fume hood and a battery of tests are performed while a gas analyzer arranged outside of the hood samples for SF6 to verify the containment properties of the fume hood.

It has been used successfully as a tracer in oceanography to study diapycnal mixing and air-sea gas exchange. [28]

Other uses

Greenhouse gas

According to the Intergovernmental Panel on Climate Change, SF
6 is the most potent greenhouse gas. Its global warming potential of 23,900 times that of CO
2 when compared over a 100-year period. [40] Sulfur hexafluoride is inert in the troposphere and stratosphere and is extremely long-lived, with an estimated atmospheric lifetime of 800–3,200 years. [41]

Measurements of SF6 show that its global average mixing ratio has increased from a steady base of about 54 parts per quadrillion [10] prior to industrialization, to over 11.5 parts per trillion (ppt) as of October 2023, and is increasing by about 0.4 ppt (3.5 percent) per year. [8] [42] Average global SF6 concentrations increased by about seven percent per year during the 1980s and 1990s, mostly as the result of its use in magnesium production, and by electrical utilities and electronics manufacturers. Given the small amounts of SF6 released compared to carbon dioxide, its overall individual contribution to global warming is estimated to be less than 0.2 percent, [43] however the collective contribution of it and similar man-made halogenated gases has reached about 10 percent as of 2020. [44] Alternatives are being tested. [45] [46]

In Europe, SF
6 falls under the F-Gas directive which ban or control its use for several applications. [47] Since 1 January 2006, SF
6 is banned as a tracer gas and in all applications except high-voltage switchgear. [48] It was reported in 2013 that a three-year effort by the United States Department of Energy to identify and fix leaks at its laboratories in the United States such as the Princeton Plasma Physics Laboratory, where the gas is used as a high voltage insulator, had been productive, cutting annual leaks by 1,030 kilograms (2,280 pounds). This was done by comparing purchases with inventory, assuming the difference was leaked, then locating and fixing the leaks. [49]

Physiological effects and precautions

Sulfur hexafluoride is a nontoxic gas, but by displacing oxygen in the lungs, it also carries the risk of asphyxia if too much is inhaled. [50] Since it is more dense than air, a substantial quantity of gas, when released, will settle in low-lying areas and present a significant risk of asphyxiation if the area is entered. That is particularly relevant to its use as an insulator in electrical equipment since workers may be in trenches or pits below equipment containing SF
6. [51]

A man's voice is deepened in pitch through inhaling sulfur hexafluoride

As with all gases, the density of SF
6 affects the resonance frequencies of the vocal tract, thus changing drastically the vocal sound qualities, or timbre, of those who inhale it. It does not affect the vibrations of the vocal folds. The density of sulfur hexafluoride is relatively high at room temperature and pressure due to the gas's large molar mass. Unlike helium, which has a molar mass of about 4 g/mol and pitches the voice up, SF
6 has a molar mass of about 146 g/mol, and the speed of sound through the gas is about 134 m/s at room temperature, pitching the voice down. For comparison, the molar mass of air, which is about 80% nitrogen and 20% oxygen, is approximately 30 g/mol which leads to a speed of sound of 343 m/s. [52]

Sulfur hexafluoride has an anesthetic potency slightly lower than nitrous oxide; [53] it is classified as a mild anesthetic. [54]

See also

Related Research Articles

In physics, the term dielectric strength has the following meanings:

<span class="mw-page-title-main">Chlorofluorocarbon</span> Class of organic compounds

Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are fully or partly halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F), produced as volatile derivatives of methane, ethane, and propane.

<span class="mw-page-title-main">Circuit breaker</span> Automatic circuit protection device

A circuit breaker is an electrical safety device designed to protect an electrical circuit from damage caused by overcurrent. Its basic function is to interrupt current flow to protect equipment and to prevent the risk of fire. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset to resume normal operation.

In electrical engineering, partial discharge (PD) is a localized dielectric breakdown (DB) of a small portion of a solid or fluid electrical insulation (EI) system under high voltage (HV) stress. While a corona discharge (CD) is usually revealed by a relatively steady glow or brush discharge (BD) in air, partial discharges within solid insulation system are not visible.

<span class="mw-page-title-main">Electric arc</span> Electrical breakdown of a gas that results in an ongoing electrical discharge

An electric arc is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma, which may produce visible light. An arc discharge is initiated either by thermionic emission or by field emission. After initiation, the arc relies on thermionic emission of electrons from the electrodes supporting the arc. An arc discharge is characterized by a lower voltage than a glow discharge. An archaic term is voltaic arc, as used in the phrase "voltaic arc lamp".

<span class="mw-page-title-main">Switchgear</span> Control gear of an electric power system

In an electric power system, a switchgear is composed of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults downstream. This type of equipment is directly linked to the reliability of the electricity supply.

Isidor Sauers (born 1948) is an Austrian-born American who is a physicist at the Oak Ridge National Laboratory in Tennessee. He is a specialist on the properties of Sulfur hexafluoride (SF6), with an important patent and over 60 peer-reviewed academic papers.

<span class="mw-page-title-main">Disulfur decafluoride</span> Chemical compound

Disulfur decafluoride is a chemical compound with the formula S2F10. It was discovered in 1934 by Denbigh and Whytlaw-Gray. Each sulfur atom of the S2F10 molecule is octahedral, and surrounded by five fluorine atoms and one sulfur atom. The two sulfur atoms are connected by a single bond. In the S2F10 molecule, the oxidation state of each sulfur atoms is +5, but their valency is 6. S2F10 is highly toxic, with toxicity four times that of phosgene.

Selenium hexafluoride is the inorganic compound with the formula SeF6. It is a very toxic colourless gas described as having a "repulsive" odor. It is not widely encountered and has no commercial applications.

A hexafluoride is a chemical compound with the general formula QXnF6, QXnF6m−, or QXnF6m+. Many molecules fit this formula. An important hexafluoride is hexafluorosilicic acid (H2SiF6), which is a byproduct of the mining of phosphate rock. In the nuclear industry, uranium hexafluoride (UF6) is an important intermediate in the purification of this element.

<span class="mw-page-title-main">Sulfur hexafluoride circuit breaker</span> Switching device used in high voltage power grids

Sulfur hexafluoride circuit breakers protect electrical power stations and distribution systems by interrupting electric currents, when tripped by a protective relay. Instead of oil, air, or a vacuum, a sulfur hexafluoride circuit breaker uses sulfur hexafluoride (SF6) gas to cool and quench the arc on opening a circuit. Advantages over other media include lower operating noise and no emission of hot gases, and relatively low maintenance. Developed in the 1950s and onward, SF6 circuit breakers are widely used in electrical grids at transmission voltages up to 800 kV, as generator circuit breakers, and in distribution systems at voltages up to 35 kV.

A dielectric gas, or insulating gas, is a dielectric material in gaseous state. Its main purpose is to prevent or rapidly quench electric discharges. Dielectric gases are used as electrical insulators in high voltage applications, e.g. transformers, circuit breakers, switchgear, radar waveguides, etc.

A liquid dielectric is a dielectric material in liquid state. Its main purpose is to prevent or rapidly quench electric discharges. Dielectric liquids are used as electrical insulators in high voltage applications, e.g. transformers, capacitors, high voltage cables, and switchgear. Its function is to provide electrical insulation, suppress corona and arcing, and to serve as a coolant.

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<span class="mw-page-title-main">Sulfur chloride pentafluoride</span> Chemical compound

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4v symmetry. Sulfur chloride pentafluoride is the only commercially available reagent for adding the –SF5 group to organic compounds.

Fluorinated gases (F-gases) are a group of gases containing fluorine. They are divided into several types, the main of those are hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF6). They are used in refrigeration, air conditioning, heat pumps, fire suppression, electronics, aerospace, magnesium industry, foam and high voltage switchgear. As they are greenhouse gases with a strong global warming potential, their use is regulated.

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The global market for chemicals from fluorine was about US$16 billion per year as of 2006. The industry was predicted to reach 2.6 million metric tons per year by 2015. The largest market is the United States. Western Europe is the second largest. Asia Pacific is the fastest growing region of production. China in particular has experienced significant growth as a fluorochemical market and is becoming a producer of them as well. Fluorite mining was estimated in 2003 to be a $550 million industry, extracting 4.5 million tons per year.

Trifluoromethylsulfur pentafluoride, CF3SF5, is a rarely used industrial greenhouse gas. It was first identified in the atmosphere in 2000. Trifluoromethylsulfur pentafluoride is considered to be one of the several "super-greenhouse gases".

A hybrid switchgear is one that combines the components of traditional air-insulated switchgear (AIS) and SF6 gas-insulated switchgear (GIS) technologies. It is characterized by a compact and modular design, which encompasses several different functions in one module.

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References

  1. ↑ "Sulfur Hexafluoride - PubChem Public Chemical Database". PubChem . National Center for Biotechnology Information. Archived from the original on 3 November 2012. Retrieved 22 February 2013.
  2. 1 2 3 4 5 NIOSH Pocket Guide to Chemical Hazards. "#0576". National Institute for Occupational Safety and Health (NIOSH).
  3. ↑ Horstmann S, Fischer K, Gmehling J (2002). "Measurement and calculation of critical points for binary and ternary mixtures". AIChE Journal . 48 (10): 2350–2356. Bibcode:2002AIChE..48.2350H. doi:10.1002/aic.690481024. ISSN   0001-1541.
  4. ↑ Assael MJ, Koini IA, Antoniadis KD, Huber ML, Abdulagatov IM, Perkins RA (2012). "Reference Correlation of the Thermal Conductivity of Sulfur Hexafluoride from the Triple Point to 1000 K and up to 150 MPa". Journal of Physical and Chemical Reference Data. 41 (2): 023104–023104–9. Bibcode:2012JPCRD..41b3104A. doi:10.1063/1.4708620. ISSN   0047-2689. S2CID   18916699.
  5. ↑ Assael MJ, Kalyva AE, Monogenidou SA, Huber ML, Perkins RA, Friend DG, May EF (2018). "Reference Values and Reference Correlations for the Thermal Conductivity and Viscosity of Fluids". Journal of Physical and Chemical Reference Data . 47 (2): 021501. Bibcode:2018JPCRD..47b1501A. doi:10.1063/1.5036625. ISSN   0047-2689. PMC   6463310 . PMID   30996494.
  6. 1 2 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A23. ISBN   978-0-618-94690-7.
  7. ↑ GHS: Record of Schwefelhexafluorid in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 2021-12-13.
  8. 1 2 "Trends in Atmospheric Sulpher Hexaflouride". US National Oceanic and Atmospheric Administration . Retrieved 28 December 2023.
  9. 1 2 3 Simmonds, P. G., Rigby, M., Manning, A. J., Park, S., Stanley, K. M., McCulloch, A., Henne, S., Graziosi, F., Maione, M., and 19 others (2020) "The increasing atmospheric burden of the greenhouse gas sulfur hexafluoride (SF6)". Atmos. Chem. Phys., 20: 7271–7290. doi : 10.5194/acp-20-7271-2020. CC-BY icon.svg Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
  10. 1 2 Busenberg, E. and Plummer, N. (2000). "Dating young groundwater with sulfur hexafluoride: Natural and anthropogenic sources of sulfur hexafluoride". Water Resources Research. 36 (10). American Geophysical Union: 3011–3030. Bibcode:2000WRR....36.3011B. doi: 10.1029/2000WR900151 .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  11. ↑ Winter RW, Pugh JR, Cook PW (January 9–14, 2011). SF5Cl, SF4 and SF6: Their Bromine−facilitated Production & a New Preparation Method for SF5Br. 20th Winter Fluorine Conference.
  12. ↑ Duward Shriver, Peter Atkins (2010). Inorganic Chemistry. W. H. Freeman. p. 409. ISBN   978-1429252553.
  13. ↑ Raj G (2010). Advanced Inorganic Chemistry: Volume II (12th ed.). GOEL Publishing House. p. 160. Extract of page 160
  14. ↑ Stöven T, Tanhua T, Hoppema M, Bullister JL (2015-09-18). "Perspectives of transient tracer applications and limiting cases". Ocean Science. 11 (5): 699–718. Bibcode:2015OcSci..11..699S. doi: 10.5194/os-11-699-2015 . ISSN   1812-0792.
  15. ↑ Constantine T. Dervos, Panayota Vassilou (2000). "Sulfur Hexafluoride: Global Environmental Effects and Toxic Byproduct Formation". Journal of the Air & Waste Management Association. 50 (1). Taylor and Francis: 137–141. Bibcode:2000JAWMA..50..137D. doi: 10.1080/10473289.2000.10463996 . PMID   10680375. S2CID   8533705.
  16. ↑ Deborah Ottinger, Mollie Averyt, Deborah Harris (2015). "US consumption and supplies of sulphur hexafluoride reported under the greenhouse gas reporting program". Journal of Integrative Environmental Sciences. 12 (sup1). Taylor and Francis: 5–16. doi: 10.1080/1943815X.2015.1092452 .
  17. ↑ Jakob F, Perjanik N, Sulfur Hexafluoride, A Unique Dielectric (PDF), Analytical ChemTech International, Inc., archived (PDF) from the original on 2016-03-04
  18. ↑ "Archived copy" (PDF). Archived (PDF) from the original on 2017-10-12. Retrieved 2017-10-12.{{cite web}}: CS1 maint: archived copy as title (link)
  19. ↑ Kieffel Y, Biquez F (1 June 2015). "SF6 alternative development for high voltage switchgears". 2015 IEEE Electrical Insulation Conference (EIC). pp. 379–383. doi:10.1109/ICACACT.2014.7223577. ISBN   978-1-4799-7352-1. S2CID   15911515 – via IEEE Xplore.
  20. ↑ "Sustainable switchgear technology for a CO2 neutral future". Siemens Energy. 2020-08-31. Retrieved 2021-04-27.
  21. ↑ Daniel A. Brinton, C. P. Wilkinson (2009). Retinal detachment: principles and practice. Oxford University Press. p. 183. ISBN   978-0199716210.
  22. ↑ Gholam A. Peyman, M.D., Stephen A. Meffert, M.D., Mandi D. Conway (2007). Vitreoretinal Surgical Techniques. Informa Healthcare. p. 157. ISBN   978-1841846262.{{cite book}}: CS1 maint: multiple names: authors list (link)
  23. ↑ Hilton GF, Das T, Majji AB, Jalali S (1996). "Pneumatic retinopexy: Principles and practice". Indian Journal of Ophthalmology. 44 (3): 131–143. PMID   9018990.
  24. ↑ Lassau N, Chami L, Benatsou B, Peronneau P, Roche A (December 2007). "Dynamic contrast-enhanced ultrasonography (DCE-US) with quantification of tumor perfusion: a new diagnostic tool to evaluate the early effects of antiangiogenic treatment". Eur Radiol. 17 (Suppl. 6): F89–F98. doi:10.1007/s10406-007-0233-6. PMID   18376462. S2CID   42111848.
  25. ↑ "SonoVue, INN-sulphur hexafluoride - Annex I - Summary of Product Characteristics" (PDF). European Medicines Agency . Retrieved 2019-02-24.
  26. ↑ C Michael Hogan (September 10, 2011). "Air pollution line source". Encyclopedia of Earth. Archived from the original on 29 May 2013. Retrieved 22 February 2013.
  27. ↑ "'Poison gas' test on Underground". BBC News. 25 March 2007. Archived from the original on 15 February 2008. Retrieved 22 February 2013.
  28. ↑ Fine RA (2010-12-15). "Observations of CFCs and SF6 as Ocean Tracers". Annual Review of Marine Science. 3 (1): 173–195. doi:10.1146/annurev.marine.010908.163933. ISSN   1941-1405. PMID   21329203.
  29. ↑ Scott C. Bartos (February 2002). "Update on EPA's manesium industry partnership for climate protection" (PDF). US Environmental Protection Agency. Archived from the original (PDF) on October 10, 2012. Retrieved December 14, 2013.
  30. 1 2 3 J. Harnisch and W. Schwarz (2003-02-04). "Final report on the costs and the impact on emissions of potential regulatory framework for reducing emissions of hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride" (PDF). Ecofys GmbH.
  31. ↑ Hopkins C (2007). Sound insulation - Google Books. Elsevier / Butterworth-Heinemann. pp. 504–506. ISBN   9780750665261.
  32. ↑ Y. Tzeng, T.H. Lin (September 1987). "Dry Etching of Silicon Materials in SF
    6     Based Plasmas"     (PDF). Journal of the Electrochemical Society. Archived from the original (PDF) on 6 April 2012. Retrieved 22 February 2013.
  33. ↑ Stanley Holmes (September 24, 2006). "Nike Goes For The Green". Bloomberg Business Week Magazine. Archived from the original on June 3, 2013. Retrieved December 14, 2013.
  34. ↑ Hughes, T.G., Smith, R.B., Kiely, D.H. (1983). "Stored Chemical Energy Propulsion System for Underwater Applications". Journal of Energy. 7 (2): 128–133. Bibcode:1983JEner...7..128H. doi:10.2514/3.62644.
  35. ↑ Dick Olsher (October 26, 2009). "Advances in loudspeaker technology - A 50 year prospective". The Absolute Sound. Archived from the original on December 14, 2013. Retrieved December 14, 2013.
  36. ↑ Edmond I Eger MD, et al. (September 10, 1968). "Anesthetic Potencies of Sulfur Hexafluoride, Carbon Tetrafluoride, Chloroform and Ethrane in Dogs: Correlation with the Hydrate and Lipid Theories of Anesthetic Action". Anesthesiology: The Journal of the American Society of Anesthesiologists. 30 (2). Anesthesiology - The Journal of the American Society of Anesthesiologists, Inc: 127–134.
  37. ↑ WTOL (2015-01-27). Sound Like Darth Vader with Sulfur Hexafluoride. YouTube. Imagination Station.
  38. ↑ Braun M, Marienfeld S, Ruf MW, Hotop H (2009-05-26). "High-resolution electron attachment to the molecules CCl4and SF6over extended energy ranges with the (EX)LPA method". Journal of Physics B: Atomic, Molecular and Optical Physics. 42 (12): 125202. Bibcode:2009JPhB...42l5202B. doi:10.1088/0953-4075/42/12/125202. ISSN   0953-4075. S2CID   122242919.
  39. ↑ Fenzlaff M, Gerhard R, Illenberger E (1988-01-01). "Associative and dissociative electron attachment by SF6 and SF5Cl". The Journal of Chemical Physics. 88 (1): 149–155. Bibcode:1988JChPh..88..149F. doi:10.1063/1.454646. ISSN   0021-9606.
  40. ↑ "2.10.2 Direct Global Warming Potentials". Intergovernmental Panel on Climate Change. 2007. Archived from the original on 2 March 2013. Retrieved 22 February 2013.
  41. ↑ A. R. Ravishankara, S. Solomon, A. A. Turnipseed, R. F. Warren, Solomon, Turnipseed, Warren (8 January 1993). "Atmospheric Lifetimes of Long-Lived Halogenated Species". Science. 259 (5092): 194–199. Bibcode:1993Sci...259..194R. doi:10.1126/science.259.5092.194. PMID   17790983. S2CID   574937. Archived from the original on 24 September 2015. Retrieved 22 February 2013.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  42. ↑ "Sulfur hexafluoride (SF6) data from hourly in situ samples analyzed on a gas chromatograph located at Cape Matatulu (SMO)". July 7, 2020. Retrieved August 8, 2020.
  43. ↑ "SF6 Sulfur Hexafluoride". PowerPlantCCS Blog. 19 March 2011. Archived from the original on 30 December 2012. Retrieved 22 February 2013.
  44. ↑ Butler J. and Montzka S. (2020). "The NOAA Annual Greenhouse Gas Index (AGGI)". NOAA Global Monitoring Laboratory/Earth System Research Laboratories.
  45. ↑ "g3, the SF6-free solution in practice | Think Grid". think-grid.org. 18 February 2019. Archived from the original on 30 October 2020. Retrieved 6 February 2020.
  46. ↑ Mohamed Rabie, Christian M. Franck (2018). "Assessment of Eco-friendly Gases for Electrical Insulation to Replace the Most Potent Industrial Greenhouse Gas SF6". Environmental Science & Technology. 52 (2). American Chemical Society: 369–380. Bibcode:2018EnST...52..369R. doi:10.1021/acs.est.7b03465. hdl: 20.500.11850/238519 . PMID   29236468.
  47. ↑ David Nikel (2020-01-15). "Sulfur hexafluoride: The truths and myths of this greenhouse gas". phys.org. Retrieved 2020-10-18.
  48. ↑ "Climate: MEPs give F-gas bill a 'green boost'". www.euractiv.com. EurActiv.com. 13 October 2005. Archived from the original on 3 June 2013. Retrieved 22 February 2013.
  49. ↑ Michael Wines (June 13, 2013). "Department of Energy's Crusade Against Leaks of a Potent Greenhouse Gas Yields Results". The New York Times . Archived from the original on June 14, 2013. Retrieved June 14, 2013.
  50. ↑ "Sulfur Hexafluoride". Hazardous Substances Data Bank. U.S. National Library of Medicine. Archived from the original on 9 May 2018. Retrieved 26 March 2013.
  51. ↑ "Guide to the safe use of SF6 in gas". UNIPEDE/EURELECTRIC. Archived from the original on 2013-10-04. Retrieved 2013-09-30.
  52. ↑ "Physics in Speech". University of New South Wales. Archived from the original on 21 February 2013. Retrieved 22 February 2013.
  53. ↑ Adriani J (1962). The Chemistry and Physics of Anesthesia (2nd ed.). Illinois: Thomas Books. p. 319. ISBN   9780398000110.
  54. ↑ Weaver RH, Virtue RW (1 November 1952). "The mild anesthetic properties of sulfur hexafluoride". Anesthesiology. 13 (6): 605–607. doi: 10.1097/00000542-195211000-00006 . PMID   12986223. S2CID   32403288.

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