Search results
Results From The WOW.Com Content Network
Infrared absorption bands prevent heat at that wavelength from escaping Earth's atmosphere. CFCs have their strongest absorption bands from C-F and C-Cl bonds in the spectral region of 7.8–15.3 μm [14] —referred to as the "atmospheric window" due to the relative transparency of the atmosphere within this region. [15]
CFC-113 was one of the most heavily produced CFCs. In 1989, an estimated 250,000 tons were produced. [5] It has been used as a cleaning agent for electrical and electronic components. [12] CFC-113’s low flammability and low toxicity made it ideal for use as a cleaner for delicate electrical equipment, fabrics, and metals.
CFCs in the Atmosphere Over Time in Parts Per Trillion. Synthetic refrigerants have been used in refrigeration systems since the creation of CFCs and HCFCs in 1929. [3] When these refrigerants leak out of systems and into the atmosphere they can have adverse results on the ozone layer and global warming.
Perfluoroalkanes are very stable because of the strength of the carbon–fluorine bond, one of the strongest in organic chemistry. [4] Its strength is a result of the electronegativity of fluorine imparting partial ionic character through partial charges on the carbon and fluorine atoms, which shorten and strengthen the bond (compared to carbon-hydrogen bonds) through favorable covalent ...
The total atmospheric concentration of F-gases, CFCs, and HCFCs has grown rapidly since the mid-twentieth century; a time which marks the start of their production and use at industrial scale. As a group in year 2019, these unnatural man-made gases are responsible for about one-tenth of the direct radiative forcing from all long-lived ...
The name is a trademark name owned by DuPont (now Chemours) for any chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), or hydrofluorocarbon (HFC) refrigerant. Following the discovery of better synthesis methods, CFCs such as R-11, [5] R-12, [6] R-123 [5] and R-502 [7] dominated the market.
1,2-Dichlorotetrafluoroethane, or R-114, also known as cryofluorane , is a chlorofluorocarbon (CFC) with the molecular formula ClF 2 CCF 2 Cl. Its primary use has been as a refrigerant. It is a non-flammable gas with a sweetish, chloroform-like odor with the critical point occurring at 145.6 °C and 3.26 MPa. When pressurized or cooled, it is a ...
[33] [34] The source of the warmth of the stratosphere is the absorption of UV radiation by ozone, hence reduced ozone leads to cooling. Some stratospheric cooling is also predicted from increases in greenhouse gases such as CO 2 and CFCs themselves; however, the ozone-induced cooling appears to be dominant. [35]