Perfluorinated anions

Phosphoric and polyphosphoric acid esters Perfluorinated anionics Sulfonic acid salts Strong surface tension reducers Good oil in water emulsifiers Soluble in polar organics Resistant to biodegradation High chemical stability Resistant to acid and alkaline hydrolysis... 

Two independent analytical methods—LC-MS-MS and 19F-NMR— for the determination of perfluorinated anionic surfactants in environmental water samples were presented. Perfluorinated alkanesulfonates and perfluorocarboxylates were determined qualitatively and quantitatively because of an accidental release of perfluorosurfactant contaminated fire-fighting foam [55]. Ci8-SPE was applied for concentration of the compounds from water samples. Methanol was used for elution prior to ESI-LC-MS(—) analysis. The negatively recorded LC-MS-MS TIC for the determination of PFOS, PFHxS, PFOA, perfluor-oheptanoic acid (PFHpA), perfluorododecanoic acid (PFDoA internal standard) in water samples was presented [55]. 

The pursuit of new lithium salts has been driven by the thermal instability of the current state-of-the-art lithium salts that were based on perfluorinated anions, and the thermal as well as chemical inertness has been taken as the main metric to evaluate any potential candidates to replace those salts, although, similar to the new solvent efforts, often the improvement in these properties comes at the price of other properties that are equally important for the operation of a lithium ion cell. 

A summary of metathesis reactions in ionic liquids is presented in Table 7.1. From the data available it appears that these reactions can easily be performed in neat ionic liquids and increased reaction rates are sometimes observed relative to molecular solvents. Co-solvents are used in some cases, mainly to obtain a biphasic system and thereby facilitate product isolation. So far, only imidazolium-type solvents have been employed with variations in the alkyl substitution pattern and the nature of the anion. Apart from the common perfluorinated anions, chloroaluminates have also been used,... 

Currently, there is concern about the use of ammonium perfluorooctanoate (APFO), also known as C8 , which is necessary for the manufacture of fluorinated plastics and elastomers in water. C8 is a perfluorinated anionic surfactant used as a dispersing agent in the polymerization and copolymerization of many fluoropolymers, including poly(tetrafluoroethylene) (PTFE), poly(vinylidene... 

The more strongly reducing (Me5C5)2Co reacts more rapidly than the parent cobaltocene, but the acidity of the methyl groups in the cation conspired against detection of the fluoride ion [73,74]. Although electron transfer is clearly important in the initial C-F activation step in these reactions, additional mechanistic study is required to assess the scope of these processes. In particular, the role of the lithium cation and possible intermediates such as perfluorinated anions need to be addressed. 

ILs bearing perfluorinated anions are expensive (in particular, those having [TfjN]" as counter anion), and the presence of fluorine makes the disposal of spent ILs more complicated. For these reasons, research on new ILs bearing inert low-coordinating and nonfluorinated anions represents a field of intense investigation in the chemistry of ILs. Among the possible alternatives recently proposed are the ILs having as carboranes and orthoborates counter anions [4]. ILs based on anions mentioned in (d) may conquer at least some of the above-mentioned problems. These anions are relatively cheap, do not contain fluorine atoms, and... 

The interest in perfluorinated ion-exchange membranes has increased extensively in recent years because of their industrial importance. A growing body of research concerning their structure and properties has developed. Much of this work has been summarized in a recent monograph. " While perfluorinated anion-exchange membranes have not yet been produced, several perfluorinated cation-exchange types have been synthesized and fabricated into membrane form, as listed in Table 1. 

It is impossible to prepare perfluorinated anion exchange membranes due to the strong electron-donor properties of the fluorine atom. For example, a stable... 

M. J. Paren, K.S. Moorhouse, Y. Zhang, G. Birznieks, T. Kruger, and M.C. PaUazzotto, New ionic photo acid generators (PAGs) incorporating novel perfluorinated anions, Proc. SPIE 4690, 817 (2002). 

Jung MJ, Arges CG, Ramani V (2011) A perfluorinated anion exchange membrane with a 1,4-dimethylpiperazinium cation. J Mater Chem 21 6158-6160. doi 10.1039/cljml0320b... 

In another quite original contribution, Mele and co-workers showed evidence of fluorous domain segregation in ionic liquids, obtained in ionic liquids with pyrrolidinium cations and perfluorinated anions of the family of fluorosulfonylamides [74]. 

Data for many other surfactants have been reported sodium alkylsulfates ° ° sodimn hexylsrdfate and hexylammonium chloride in brine solution i octylam-monium chloride, octyltrimethylammonium chloride and bromide, and sodium and potassium capiylates sodium /j-(l-propylnonyl)benzenesulfonate ii dode-cylp5rridinium chloride and bromide heptylammo-nium chloride nonionic surfactants C ,H2 ,+i (OCHgCHglnOH with various m and n values perfluorinated anionic surfactants and cationic surfactants with a perfluoroalkylcarboxylate counterion. Some of these data must be reanalyzed using Equation 3.9 or, if the required data are available, Equation 3.16, in order to extract meaningful rate constants. 

The surface tensions of some perfluorinated anionic surfactants with a CsFi7— hydrophobe in strong acids are given in Table 4.9 [56]. The surfactant CgFivSOsK is very effective in concentrated acids, although its solubility in 37% hydrochloric acid is limited to 0.2 g/L. 

The stability of perfluorinated anionic surfactants is also remarkable in alkali. Glockner et al. [79] found the surface tensions of perfluorinated anionic surfactants in saturated aqueous sodium hydroxide to be constant for at least 100 days (Table 4.11). Salts of perfluoroalkanoic, perfluoroalkanesulfonic, or perfluo-roalkenesulfonic acids survived an alkaline fusion [5 g KN03/LiN03 (35-65 mol%), 0.5 g NaOH, 0.05 g surfactant] for 2 h at 200°C, as indicated by the surface tensions of the aqueous solutions of the fusion mass. 

Radiation induced redox reactions and the fragmentation of constituent ions in ILs are phenomena which have to be known in detail when using ILs in solar cells, electrolytes etc. Anion fragmentation in ILs starts with radiation induced redox reactions. Scission of the oxidized anions is the main fragmentation pathway, in competition with internal proton transfer reactions involving the aliphatic chains of these anions. Perfluorinated anions show a fluoride loss after a dissociative electron attachment. For example CF3SO3 +e -f CF2S03 is a typical re-... 

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