Hydrofluoroethers (HFEs) are a class of organic
solvent
A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvÅ'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas ...
s. As non-ozone-depleting chemicals, they were developed originally as a replacement for
CFCs
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are fully or partly halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F). They are produced as volatile derivatives of methane, ethane, ...
,
HFCs,
HCFCs, and
PFCs. They are typically colorless, odorless, tasteless, low toxicity, low viscosity, and liquid at room temperature. The
boiling point
The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.
The boiling point of a liquid varies depending upon the surrounding envi ...
of HFEs vary from to nearly . Although 3M first developed HFEs, other manufacturers have begun producing them.
Applications
Industrial uses are many and varied, including:
* Vapor de-greasing solvent
* Refrigerant and heat-transfer fluid
* Anhydrous fluid cleaner
They are sometimes applied as blends such as HFE 7100, which is a mixture of methyl nonafluorobutyl ether (
methoxyperfluorobutane) and methyl nonafluoroisobutyl ether.
3M produces hydrofluoroether compounds under the names Novec 7000, 7100, 7200, 7300, 7500, and 7700 as liquid coolants for many applications, including full immersion cooling of computer electronics.
Environmental impact
Because of their high
molecular weight
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemi ...
s, HFEs remain in the
atmosphere
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...
for less than two weeks, being absorbed into the ground rather than remaining dissolved in the atmosphere. Although HFEs are
greenhouse gas
Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. T ...
es, the EPA does not regulate their use due to the short atmospheric lifetimes and zero
ozone depletion potential
The ozone depletion potential (ODP) of a chemical compound is the relative amount of degradation to the ozone layer it can cause, with trichlorofluoromethane (R-11 or CFC-11) being fixed at an ODP of 1.0. Chlorodifluoromethane (R-22), for examp ...
compared to alternative chemicals.
See also
*
Immersion cooling
*
Liquid dielectric
*
Novec 649 and 774
*
Fluorinert
Fluorinert is the trademarked brand name for the line of electronics coolant liquids sold commercially by 3M. As perfluorinated compounds (PFCs), all Fluorinert variants have an extremely high global warming potential (GWP), so should be used with ...
External links
Heat transfer applications using 3M Novec Engineered Fluids
References
{{Reflist
Coolants
Ethers
Liquid dielectrics
Organofluorides