Functionalization of saturated fluorocarbons with and without light

Chen, Xudong; Lemal, David M.

doi:10.1016/j.jfluchem.2006.06.005

Cited by 4 publications

(2 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Studies on linear fluorochemicals containing only secondary 20 and primary 33 C-F bonds are limited due to low (E < -2.7 V) reduction potentials. 34,35 Reductive fluoride elimination is influenced by a number of chemical properties such as C-F bonding character (e.g., σ vs π character), 26 electron density, 36 redox potential, 35 anion radical stability, 25 ionic headgroup, 16 -(CF 2 ) nchain length, 20 and electrondonating reagent strength. 37 The activation energies of aqueous electron reactions with halo-organics are invariable and small (6 to 30 kJ/mol) due to tunneling effects.…”

Section: •-mentioning

confidence: 99%

“…Reductive remediation of perfluorocarboxylates and perfluorosulfonates is feasible. − For example, PFOS and PFHS can be reduced by elemental iron (Fe(0), E = −0.447 V) in water under extreme conditions (350 °C, 20 MPa). , Aromatic, , benzylic, olefinic, , and tertiary − fluoroorganics readily undergo reductive defluorination by chemical and electrochemical methods. Studies on linear fluorochemicals containing only secondary and primary C−F bonds are limited due to low ( E < −2.7 V) reduction potentials. , Reductive fluoride elimination is influenced by a number of chemical properties such as C−F bonding character (e.g., σ vs π character), electron density, redox potential, anion radical stability, ionic headgroup, −(CF 2 ) n − chain length, and electron-donating reagent strength . The activation energies of aqueous electron reactions with halo-organics are invariable and small (6 to 30 kJ/mol) due to tunneling effects .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Reductive Defluorination of Aqueous Perfluorinated Alkyl Surfactants: Effects of Ionic Headgroup and Chain Length

et al. 2009

View full text Add to dashboard Cite

Perfluorinated chemicals (PFCs) are distributed throughout the environment. In the case of perfluorinated alkyl carboxylates and sulfonates, they can be classified as persistent organic pollutants since they are resistant to environmentally relevant reduction, oxidation, and hydrolytic processes. With this in mind, we report on the reductive defluorination of perfluorobutanoate, PFBA (C(3)F(7)CO(2)(-)), perfluorohexanoate, PFHA (C(5)F(11)CO(2)(-)), perfluorooctanoate, PFOA (C(7)F(15)CO(2)(-)), perfluorobutane sulfonate, PFBS (C(4)F(9)SO(3)(-)), perfluorohexane sulfonate, PFHS (C(6)F(13)SO(3)(-)), and perfluorooctane sulfonate, PFOS (C(8)F(17)SO(3)(-)) by aquated electrons, e(aq)(-), that are generated from the UV photolysis (lambda = 254 nm) of iodide. The ionic headgroup (-SO(3)(-) vs -CO(2)(-)) has a significant effect on the reduction kinetics and extent of defluorination (F index = -[F(-)](produced)/[PFC](degraded)). Perfluoroalkylsulfonate reduction kinetics and the F index increase linearly with increasing chain length. In contrast, perfluoroalkylcarboxylate chain length appears to have a negligible effect on the observed kinetics and the F index. H/F ratios in the gaseous fluoro-organic products are consistent with measured F indexes. Incomplete defluorination of the gaseous products suggests a reductive cleavage of the ionic headgroup occurs before complete defluorination. Detailed mechanisms involving initiation by aquated electrons are proposed.

show abstract

Section: •-mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Reductive Defluorination of Aqueous Perfluorinated Alkyl Surfactants: Effects of Ionic Headgroup and Chain Length

et al. 2009

View full text Add to dashboard Cite

show abstract

Functionalization of Saturated Fluorocarbons with and Without Light.

Chen

Lemal

2007

ChemInform

View full text Add to dashboard Cite

show abstract

Treatment technologies for aqueous perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA)

Vecitis

Park

Cheng

et al. 2009

Front. Environ. Sci. Eng. China

376

256

View full text Add to dashboard Cite

Fluorochemicals (FCs) are oxidatively recalcitrant, environmentally persistent, and resistant to most conventional treatment technologies. FCs have unique physiochemical properties derived from fluorine which is the most electronegative element. Perfluorooctanesulfonate (PFOS), and perfluorooctanoate (PFOA) have been detected globally in the hydrosphere, atmosphere and biosphere. Reducing treatment technologies such as reverses osmosis, nano-filtration and activated carbon can remove FCs from water. However, incineration of the concentrated waste is required for complete FC destruction. Recently, a number of alternative technologies for FC decomposition have been reported. The FC degradation technologies span a wide range of chemical processes including direct photolysis, photocatalytic oxidation, photochemical oxidation, photochemical reduction, thermally-induced reduction, and sonochemical pyrolysis. This paper reviews these FC degradation technologies in terms of kinetics, mechanism, energetic cost, and applicability. The optimal PFOS/PFOA treatment method is strongly dependent upon the FC concentration, background organic and metal concentration, and available degradation time.

show abstract

Functionalization of saturated fluorocarbons with and without light

Cited by 4 publications

References 53 publications

Reductive Defluorination of Aqueous Perfluorinated Alkyl Surfactants: Effects of Ionic Headgroup and Chain Length

Reductive Defluorination of Aqueous Perfluorinated Alkyl Surfactants: Effects of Ionic Headgroup and Chain Length

Functionalization of Saturated Fluorocarbons with and Without Light.

Treatment technologies for aqueous perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA)

Contact Info

Product

Resources

About