Full defluorination and degradation of per- and poly-fluoroalyl substances under mild conditions

Abstract

A method of treating organofluorine compounds in mild conditions includes dissolving a first amount of strong nucleophile in a liquid solution, adding a second amount of an organofluorine sample to the liquid solution, heating the solution, and reacting the solution from the introduction of the chemicals up to 48 hours.

Description

Atty. Docket No. GEN013FP308AWOFULL DEFLUORINATION AND DEGRADATION OF PER- AND POLY-FLUOROALYL SUBSTANCES UNDER MILD CONDITIONS CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 63 / 725,931, filed on November 27, 2024, entitled "FULL DEFLUORINATION AND DEGRADATION OF PFAS UNDER MILD CONDITIONS," the disclosure of which is hereby incorporated herein by reference in its entirety.FIELD OF THE DISCLOSURE

[0002] The present disclosure generally relates to methods for full defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS), and more particularly to defluorination and degradation methods for PFAS under mild conditions with ambient pressure, and lowtemperature, and more particularly without using harsh corrosive, toxic, or highly expensive chemical, such as alkali metals, strong acids like sulfuric acid, or strong bases like sodium hydroxide or potassium hydroxide.BACKGROUND

[0003] Per- and poly-fluoroalkyl substances (PFAS), also known as "forever chemicals", are an emerging class of pollutants widely present in surface / ground waters and soils. These compounds have been used for over 60 years in hundreds of industrial applications a nd consumer products [e.g., carpet, apparel, upholstery, cookware, food wrappers, and aqueous fire-fighting foams (AFFFs)]. The term "forever chemicals" reflects the high chemical stability of PFAS, which renders them highly resistant to hydrolysis, biodegradation, metabolism, photolysis (sunlight), and other degradation processes. Due to the toxicity and tendency to bioaccumulate, the United States Environmental Protection Agency (EPA) has prioritized them as top unregulated contaminants. The chemical stability of PFAS compounds is owed to the stable carbon-fluorine bonds in their structure. The U.S. and European countries have begun to ban the manufacturing and use of many PFAS, but efforts to remediate the global spread of PFAS will likely take several decades.

[0004] Current methods for treatment of PFAS include thermolysis, pyrolysis in an inert atmosphere or combustion in the presence of oxygen, to destroy the PFAS molecules. Thermolysis can lead to inefficient degradation and generation of secondary pollutants. During thermolysis, many volatile PFAS compounds, especially those with shorter carbon chains (less than seven carbons), can escape into the atmosphere along with vapor emissions.These volatiles may be the original PFAS compounds or byproducts from incomplete thermal decomposition. The byproducts include short -chain (between four to seven carbons) and ultrashort-chain (between two and three carbon chains) perfluoroalkanes and alkenes, along with non-PFAS fluorocarbons. The release of these volatile compounds into the environment creates further pollution concerns. Given the high thermal stability of PFAS, thermolysis is generally not an effective method for complete destruction. Even at temperatures exceeding 800°C, full decomposition cannot be guaranteed. Therefore, thermolysis is not ideal for defluorination, which is crucial for the detoxification of PFAS.SUMMARY OF THE DISCLOSURE

[0005] According to one aspect of the present disclosure, a method of defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS) includes contacting a sample containing PFAS with a strong nucleophile, wherein the strong nucleophile is selected from a group consisting of thiolate anion, wherein the thiolate anion comprises RiS", wherein Ri is hydrogen, alkyl, alkoxy or another group that is not electron withdrawing, alkoxide anion, wherein the alkoxide anion comprises R2O’, wherein R2is hydrogen, alkyl, alkoxy or another group that is not electron withdrawing, amide ion, wherein the amide ion comprises NH2‘, hydrazine, azide, primary a mine, wherein the primary a mine comprises R3-NH2, wherein R3is hydrogen, alkyl, alkoxy, or another group that is not electron withdrawing, enolate anion, wherein the enolate anion comprises R4RsC=O’, wherein R4and R5can independently be alkyl, alkyoxy, or another group that is not electron withdrawing, carbon anion, wherein the carbon anion comprise ReRzRs-C", wherein R6, R7, and R8is hydrogen, alkyl, alkoxy, or anothergroup that is not electron withdrawing, acetylide ion, wherein the acetylide ion comprises R9C C, wherein R9is hydrogen, alkyl, alkoxy, or anothergroup that is not electron withdrawing, and iodide ion, and heating the sample to a temperature for 24 hours, wherein the temperature is around or less than 200°C.

[0006] According to another aspect of the present disclosure, a method of treating orga nofluorine compounds in mild conditions includes dissolving a first amount of strong nucleophile in a liquid solution, addinga second amount of an organofluorine sample to the liquid solution, heatingthe solution, and reacting the solution from introduction of chemicals up to 48 hours.

[0007] Accordingto anotheraspect ofthe present disclosure, a method of defluorinatingand degrading per- and poly-fluoroalkyl substances (PFAS) through a nucleophilic reaction, themethod including dissolving said PFAS in a solution, adding a nucleophile to the solution in molar excess of the PFAS the nucleophile is selected from a group consisting of methane thiolate, ethane thiolate, amide, methoxide, and ethoxide, and heating the solution to at least 85 °C for up to 72 hours.

[0008] These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In the drawings:

[0010] FIG. 1 illustrates anexemplaryelectron pushing mechanism forthe defluorination and degradation of an exemplary organofluorine compound via nucleophilic reaction using methane thiolate as an example nucleophile resulting in fluoride ions and other small compounds, according to aspects of the present disclosure;

[0011] FIG. 2 isan illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 150 °C, according to aspects of the present disclosure;

[0012] FIG. 3 isan illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 130 °C, according to aspects of the present disclosure;

[0013] FIG. 4 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-N MR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0014] FIG. 5 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-N MR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium ethane thiolate at 110 °C, according to aspects of the present disclosure;

[0015] FIG. 6 is an i 11 ustratio n of a fluorine-19 nuclear magneticresonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 150 °C, according to aspects of the present disclosure;

[0016] FIG. 7 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-N MR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 130 °C, according to aspects of the present disclosure;

[0017] FIG. 8 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-N MR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 110 °C, according to aspects of the present disclosure;

[0018] FIG. 9 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-N MR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium methoxide at 110 °C, according to aspects of the present disclosure;

[0019] FIG. 10 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium methane thiolate at 28 °C, according to aspects of the present disclosure;

[0020] FIG. 11 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 28 °C, according to aspects of the present disclosure;

[0021] FIG. 12 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium methane thiolate at 60 °C, according to aspects of the present disclosure;

[0022] FIG. 13 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 60 °C, according to aspects of the present disclosure;

[0023] FIG. 14 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium methane thiolate at 85 °C, according to aspects of the present disclosure;

[0024] FIG. 15 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 85 °C, according to aspects of the present disclosure;

[0025] FIG. 16 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progressof perfluorooctanoicacid (PFOA) with hydrazine at 110 °C, according to aspects of the present disclosure;

[0026] FIG. 17 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoicacid (PFOA) with l,8-diazabicyclo[5.4.0]undec- 7-ene (DBU) at 110 °C with dimethyl sulfoxide as the solvent, according to aspects of the present disclosure;

[0027] FIG. 18 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoicacid (PFOA) with l,8-diazabicyclo[5.4.0]undec- 7-ene (DBU) at 110 °C with dimethyl sulfoxide and waterasthe solvent, accordingto aspects of the present disclosure;

[0028] FIG. 19 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0029] FIG. 20 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoicacid (PFOA) with sodium ethane thiolate at 110 °C, according to aspects of the present disclosure;

[0030] FIG. 21 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium ethoxide at 110 °C, according to aspects of the present disclosure;

[0031] FIG. 22 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium methoxide at 110 °C, according to aspects of the present disclosure;

[0032] FIG. 23 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 150 °C, according to aspects of the present disclosure;

[0033] FIG. 24 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 130 °C, according to aspects of the present disclosure;

[0034] FIG. 25 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 110 °C, according to aspects of the present disclosure;

[0035] FIG. 26 is an illustration of several fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 85 °C, according to aspects of the present disclosure;

[0036] FIG. 27 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 60 °C, according to aspects of the present disclosure;

[0037] FIG. 28 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 28 °C, according to aspects of the present disclosure;

[0038] FIG. 29 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium amide at 150 °C, according to aspects of the present disclosure;

[0039] FIG. 30 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium methane thiolate at 130 °C, according to aspects of the present disclosure;

[0040] FIG. 31 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium methane thiolate at 85 °C, according to aspects of the present disclosure;

[0041] FIG. 32 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctanoic acid (PFOA) with sodium methane thiolate at 60 °C, according to aspects of the present disclosure;

[0042] FIG. 33 is a linearfitforthe first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 28 °C, according to aspects of the present disclosure;

[0043] FIG. 34 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium amide at 28 °C, according to aspects of the present disclosure;

[0044] FIG. 35 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 60 °C, according to aspects of the present disclosure;

[0045] FIG. 36 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium amide at 60 °C, according to aspects of the present disclosure;

[0046] FIG. 37 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 85 °C, according to aspects of the present disclosure;

[0047] FIG. 38 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium amide at 85 °C, according to aspects of the present disclosure;

[0048] FIG. 39 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0049] FIG. 40 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium amide at 110 °C, according to aspects of the present disclosure;

[0050] FIG. 41 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 130 °C, according to aspects of the present disclosure;

[0051] FIG. 42 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium amide at 130 °C, according to aspects of the present disclosure;

[0052] FIG. 43 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 150 °C, according to aspects of the present disclosure;

[0053] FIG. 44 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium amide at 150 °C, according to aspects of the present disclosure;

[0054] FIG. 45 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium ethane thiolate at 110 °C, according to aspects of the present disclosure;

[0055] FIG. 46 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methoxide at 110 °C, according to aspects of the present disclosure;

[0056] FIG. 47 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium amide at 60 °C, according to aspects of the present disclosure;

[0057] FIG. 48 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium amide at 85 °C, according to aspects of the present disclosure;

[0058] FIG. 49 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium amide at 110 °C, according to aspects of the present disclosure;

[0059] FIG. 50 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium amide at 130 °C, according to aspects of the present disclosure;

[0060] FIG. 51 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 150 °C, according to aspects of the present disclosure;

[0061] FIG. 52 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 60 °C, according to aspects of the present disclosure;

[0062] FIG. 53 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 85 °C, according to aspects of the present disclosure;

[0063] FIG. 54 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0064] FIG. 55 is a linear fit for the first order kinetics of the degradation of perfluorooctanoic acid (PFOA) by sodium methane thiolate at 130 °C, according to aspects of the present disclosure;

[0065] FIG. 56 is an Arrhenius plot for the reaction between perfluorooctanoic acid (PFOA) and sodium methane thiolate, according to aspects of the present disclosure;

[0066] FIG. 57 is an Arrhenius plot for the reaction between perfluorooctanoic acid (PFOA) and sodium amide, according to aspects of the present disclosure;

[0067] FIG. 58 is an Arrhenius plot for the reaction between perfluorooctanoic acid (PFOA) and sodium methane thiolate, according to aspects of the present disclosure;

[0068] FIG. 59 is an Arrhenius plot for the reaction between perfluorooctanoic acid (PFOA) and sodium methane thiolate, according to aspects of the present disclosure;

[0069] FIG. 60 is a linearcalibration curve for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for varying concentrations of fluoride ions, according to aspects of the present disclosure;

[0070] FIG. 61 is a linearcalibration curve using a standard addition method forthe integrated area of the fluoride ion peakon a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorooctanoic acid (PFOA) and sodium methane thiolate, according to aspects of the present disclosure;

[0071] FIG. 62 is a linearcalibration curve using a standard addition method forthe integrated area of the fluoride ion peakon a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorooctanoic acid (PFOA) and sodium ethane thiolate, according to aspects of the present disclosure;

[0072] FIG. 63 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorooctanoic acid (PFOA) and sodium amide, according to aspects of the present disclosure.

[0073] FIG. 64 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorooctanoicacid (PFOA) and sodium methoxide, according to aspects of the present disclosure;

[0074] FIG. 65 is a line graph showing the percent of fluoride recovery for the reaction of perfluorooctanoic acid (PFOA) for various nucleophiles dependent on time, according to aspects of the present disclosure;

[0075] FIG. 66 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorooctanoic acid (PFOA) and sodium amide, according to aspects of the present disclosure;

[0076] FIG. 67 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorooctanoic acid (PFOA) and sodium methane thiolate, according to aspects of the present disclosure;

[0077] FIG. 68 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorooctanoic acid (PFOA) and sodium ethane thiolate, according to aspects of the present disclosure;

[0078] FIG. 69 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorooctanoic acid (PFOA) and sodium amide, according to aspects of the present disclosure;

[0079] FIG. 70 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorooctanoic acid (PFOA) and sodium ethoxide, according to aspects of the present disclosure;

[0080] FIG. 71 is a line graph showing the percent of fluoride recovery for the reaction of perfluorooctanoic acid (PFOA) for various nucleophiles dependent on time, according to aspects of the present disclosure;

[0081] FIG. 72 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorononanoic acid (PFNA) with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0082] FIG. 73 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorononanoic acid (PFNA) with sodium amide at 110 °C, according to aspects of the present disclosure;

[0083] FIG. 74 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorononanoic acid (PFNA) and sodium methane thiolate, according to aspects of the present disclosure;

[0084] FIG. 75 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorononanoic acid (PFNA) and sodium amide, according to aspects of the present disclosure;

[0085] FIG. 76 is a line graph showing the percent of fluoride recovery for the reaction of perfluorononanoic acid (PFNA) for various nucleophiles dependent on time, according to aspects of the present disclosure;

[0086] FIG. 77 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorononanoic acid (PFNA) and sodium amide, to determine trifluoroacetic acid concentration, according to aspects of the present disclosure;

[0087] FIG. 78 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorononanoic acid (PFNA) with sodium amide at 110 °C, according to aspects of the present disclosure;

[0088] FIG. 79 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorononanoic acid (PFNA) and sodium amide, according to aspects of the present disclosure;

[0089] FIG. 80 is a line graph showing the percent of fluoride recovery for the reaction of perfluoronona noic acid (PFNA) for sodium amide dependent on time, according to aspects of the present disclosure;

[0090] FIG. 81 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorobutanoic acid (PFBA) with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0091] FIG. 82 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorobutanoic acid (PFBA) with sodium amide at 110 °C, according to aspects of the present disclosure;

[0092] FIG. 83 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorobutanoic acid (PFBA) and sodium methane thiolate, according to aspects of the present disclosure;

[0093] FIG. 84 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorobutanoic acid (PFBA) and sodium amide, according to aspects of the present disclosure;

[0094] FIG. 85 is a line graph showing the percent of fluoride recovery for the reaction of perfluorobutanoic acid (PFBA) for various nucleophiles dependent on time, according to aspects of the present disclosure;

[0095] FIG. 86 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorobutanoic acid (PFBA) with sodium amide at 110 °C, according to aspects of the present disclosure;

[0096] FIG. 87 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorobutanoic acid (PFBA) and sodium amide, according to aspects of the present disclosure;

[0097] FIG. 88 is a line graph showing the percent of fluoride recovery for the reaction of perfluorobutanoic acid (PFBA) for sodium amide dependent on time, according to aspects of the present disclosure;

[0098] FIG. 89 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of GenX™ with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0099] FIG. 90 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of GenX™ with sodium amide at 110 °C, according to aspects of the present disclosure;

[0100] FIG. 91 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of GenX™ with sodium methane thiolate at 150 °C, according to aspects of the present disclosure;

[0101] FIG. 92 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of GenX™ with sodium amide at 150 °C, according to aspects of the present disclosure;

[0102] FIG. 93 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between GenX™ and sodium methane thiolate, according to aspects of the present disclosure;

[0103] FIG. 94 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between GenX™ and sodium amide, according to aspects of the present disclosure;

[0104] FIG. 95 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between GenX™ and sodium methane thiolate, according to aspects of the present disclosure;

[0105] FIG. 96 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between GenX™ and sodium amide, according to aspects of the present disclosure;

[0106] FIG. 97 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of GenX™ with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0107] FIG. 98 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of GenX™ with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0108] FIG. 99 is a line graph showing the percent of fluoride recovery for the reaction of GenX™ for sodium amide dependenton time, accordingto aspects of the present disclosure;

[0109] FIG. 100 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of lH-perfluoroheptane with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0110] FIG. 101 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of lH-perfluoroheptane with sodium amide at 110 °C, according to aspects of the present disclosure;

[0111] FIG. 102 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between lH-perfluoroheptane and sodium methane thiolate, according to aspects of the present disclosure;

[0112] FIG. 103 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum forthe reaction between lH-perfluoroheptane and sodium amide, according to aspects of the present disclosure;

[0113] FIG. 104 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between lH-perfluoroheptane and amide, according to aspects of the present disclosure;

[0114] FIG. 105 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of lH-perfluoroheptane with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0115] FIG. 106 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum forthe reaction between lH-perfluoroheptane and sodium amide, according to aspects of the present disclosure;

[0116] FIG. 107 is a line graph showing the percent of fluoride recovery for the reaction of lH-perfluoroheptane for sodium amide dependent on time, according to aspects of the present disclosure;

[0117] FIG. 108 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of trifluoroacetic acid with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0118] FIG. 109 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of trifluoroaceticacid with sodium amide at 110 °C, according to aspects of the present disclosure;

[0119] FIG. 110 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of trifluoroacetic acid with sodium methane thiolate at 150 °C, according to aspects of the present disclosure;

[0120] FIG. Ill is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of trifluoroaceticacid with sodium amide at 150 °C, according to aspects of the present disclosure;

[0121] FIG. 112 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between trifluoroacetic acid and sodium methane thiolate, according to aspects of the present disclosure;

[0122] FIG. 113 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum forthe reaction between trifluoroaceticacid and sodium amide, according to aspects of the present disclosure;

[0123] FIG. 114 is an Arrhenius plot forthe reaction between trifluoroaceticacid and sodium methane thiolate, according to aspects of the present disclosure;

[0124] FIG. 115 is an Arrhenius plot forthe reaction between trifluoroaceticacid and sodium amide, according to aspects of the present disclosure;

[0125] FIG. 116 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of trifluoroaceticacid with sodium amide at 110 °C, according to aspects of the present disclosure;

[0126] FIG. 117 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of trifluoroaceticacid with sodium amide at 150 °C, according to aspects of the present disclosure;

[0127] FIG. 118 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum forthe reaction between trifluoroaceticacid and sodium amide, according to aspects of the present disclosure;

[0128] FIG. 119 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum forthe reaction between trifluoroaceticacid and sodium amide, according to aspects of the present disclosure;

[0129] FIG. 120 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluorooctane sulfonicacid potassium salt (PFOSK) with sodium amide at 150 °C, according to aspects of the present disclosure;

[0130] FIG. 121 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between perfluorooctane sulfonic acid potassium salt (PFOSK) and sodium amide, according to aspects of the present disclosure;

[0131] FIG. 122 is a line graph showing the percent of fluoride recovery for the reaction of perfluorooctane sulfonic acid potassium salt (PFOSK) for sodium amide dependent on time, according to aspects of the present disclosure;

[0132] FIG. 123 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum forthe reaction between polyvinylidenefluoride (PVDF) and sodium methane thiolate, according to aspects of the present disclosure;

[0133] FIG. 124 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between polyvinylidenefluoride (PVDF) and sodium amide, according to aspects of the present disclosure;

[0134] FIG. 125 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum forthe reaction between polyvinylidenefluoride (PVDF) and sodium methane thiolate, according to aspects of the present disclosure;

[0135] FIG. 126 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between polyvinylidenefluoride (PVDF) and sodium amide, according to aspects of the present disclosure;

[0136] FIG. 127 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between polyvinylidenefluoride (PVDF) and sodium amide, according to aspects of the present disclosure;

[0137] FIG. 128 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between polyvinylidenefluoride (PVDF) and sodium amide, according to aspects of the present disclosure;

[0138] FIG. 129 is a line graph showing the percent of fluoride recovery for the reaction of polyvinylidene fluoride (PVDF) for sodium amide dependent on time, according to aspects of the present disclosure;

[0139] FIG. 130 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between polychlorotrifluoroethylene (PCTFE) and sodium methane thiolate, according to aspects of the present disclosure;

[0140] FIG. 131 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between polychlorotrifluoroethylene (PCTFE) and sodium amide, according to aspects of the present disclosure;

[0141] FIG. 132 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between polychlorotrifluoroethylene (PCTFE) and sodium methane thiolate, according to aspects of the present disclosure;

[0142] FIG. 133 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between polychlorotrifluoroethylene (PCTFE) and sodium amide, according to aspects of the present disclosure;

[0143] FIG. 134 is a line graph showing the percent of fluoride recovery for the reaction of polychlorotrifluoroethylene (PCTFE) for sodium methane thiolate and sodium amide dependent on time, according to aspects of the present disclosure;

[0144] FIG. 135 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between polychlorotrifluoroethylene (PCTFE) and sodium amide, according to aspects of the present disclosure;

[0145] FIG. 136 is a line graph showing the percent of fluoride recovery for the reaction of polychlorotrifluoroethylene (PCTFE) for sodium amide dependent on time, according to aspects of the present disclosure;

[0146] FIG. 137 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluoropropionic acid with sodium amide at 110 °C, according to aspects of the present disclosure;

[0147] FIG. 138 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum for the reaction between perfluoropropionic acid and sodium amide, according to aspects of the present disclosure;

[0148] FIG. 139 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluoro-l-heptene with sodium amide at 110 °C, according to aspects of the present disclosure;

[0149] FIG. 140 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectra of the reaction progress of perfluoro-l-heptene with sodium methane thiolate at 110 °C, according to aspects of the present disclosure;

[0150] FIG. 141 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F- NMR) spectrum forthe reaction between perfluoro-l-heptene and sodium methane thiolate, according to aspects of the present disclosure;

[0151] FIG. 142 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluoro-l-heptene and sodium amide, according to aspects of the present disclosure;

[0152] FIG. 143 is a line graph showing the percent of fluoride recovery for the reaction of perfluoro-l-heptene for sodium methane thiolate dependent on time, according to aspects of the present disclosure; and

[0153] FIG. 144 is a line graph showing the percent of fluoride recovery for the reaction of perfluoro-l-heptene for sodium amide dependent on time, according to aspects of the present disclosure.DETAILED DESCRIPTION

[0154] The present illustrated embodiments reside primarily in combinations of method steps and apparatus components related to full defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS) under mild conditions, ambient pressure, and low temperature. Accordingly, the apparatus components and method steps have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Further, like numerals in the description and drawings represent like elements.

[0155] For purposes of description herein, the terms "upper," "lower," "right," "left," "rear," "front," "vertical," "horizontal," and derivatives thereof, shall relate to the disclosure as oriented in FIG. 1. Unless stated otherwise, the term "front" shall refer to a surface of the device closest to an intended viewer, and the term "rear" shall referto a surface of the device furthest from the intended viewer. However, it is to be understood that the disclosure may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions a nd other physical characteristics relatingto the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

[0156] The terms "including," "comprises," "comprising," or any other variation thereof, are intended to covera non-exclusive inclusion, such thata process, method, article, orapparatus that comprises a list of elements does not include onlythose elements but may include otherelements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by "comprises a . . . " does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0157] The present disclosure relates to defluorination and degradation of per- and polyfluoroalkyl substances (PFAS) using strong nucleophiles and breaking the substances down into ions or small molecules including by not limited to fluoride ions (F ), trifluoroacetic acid (TFA), acetic acid, and formic acid. The target PFAS include, but are not limited to, perfluorooctanoic acid (PFOA), pefluorononanoic acid (PFNA), perfluorobutanesulfonic acid (PFBS), an ammonium salt of hexafluoropropylene oxide dimer acid (GenX™), 1H- perfluoroheptane (lH-PFHp), and perfluorooctanesulfonic acid (PFOS). In some implementations, the target substances may include other organofluorine compounds such as trifluoroacetic acid (TFA). These methods of defluorination and degradation are conducted under mild conditions, such as ambient pressure a nd relatively low temperatures a round and less than 100°C, without the use of harsh reagents like strong bases (e.g., sodium hydroxide, potassium hydroxide) or intense reaction conditions involving high-energy UV light, electron beams, plasma, or oxygen free (e.g. under argon protection) as required for photocata lytic reduction. In some examples, the strong nucleophile may be thiolate anions, (e.g., methane thiolate, ethane thiolate), alkoxide anions (e.g., methoxide), amide ions (e.g., azanide), hydrazine, azides, primary amines, enolate anions, carbon anions, acetylide ions, and iodide ions. In some aspects, complete degradation of PFAS may be achieved within 0.5 hours dependent on reaction temperature.

[0158] Referring to FIG. 1, the present disclosure utilizes a method based on a nucleophilic reaction between PFAS and a strong nucleophile (e.g., methane thiolate). Withoutwishingto be bound by theory, the nucleophilic reaction may break the carbon -fluorine (C-F) bond and may liberate fluoride ions (F ). Further, the nucleophilic reaction may breakthe carbon-carbon (C-C) bond and may produce small fluorine-free molecules. Current methods prove the difficulty of the degradation of PFAS due to a high thermal stability of these molecules. The high thermal stability is attributed to the strength of the C-F bond, resulting from a bond energy of 485 kJ / mol. The C-F bond is much stronger than bonds found in common organic molecules, such as C-C bond (347 kJ / mol) and carbon-hydrogen (C-H) bond (413 kJ / mol).

[0159] Current methods of defluorination and / or degradation of PFAS often use harsh reagents such as strong bases (e.g., sodium hydroxide, potassium hydroxide), use intense reaction conditions involving high temperatures (e.g., >500 °C), high-energy UV light, electron beams, or plasma, require high energy inputs, or generate secondary pollutants. The method of the current disclosure may not only be effective in achieving complete defluorination but may also be environmentally sustainable by minimizingthe production ofsecondary waste or pollutants.

[0160] According to another method of the present disclosure, the selection of a reagent molecule for defluorination and degradation may be selected based on the molecule's nucleophilicity not necessarily the molecule's basicity. The higher the strength of a nucleophile as opposed to the higher strength of a base may lead to a more effective PFAS degradation. For example, l,8-diazabicyclo[5.4.0]undec-7-ene (DBU), a strong organic base may only be effective at initiating decarboxylation of specific PFAS with carboxylic acid moieties but may have no defluorination potential of said PFAS. This is primarily because DBU, despite its strong basicity, is not an efficient nucleophile due to steric hindrance from its bulky structure. The steric hinderance of a molecule may affect the molecule's nucleophilicity. Defluorination and degradation of PFAS may be predominantly influenced by nucleophilicity rather than basicity.

[0161] Further, smaller sized reagents may be more effective of defluorination and degradation of PFAS. This is consistent with the smaller the molecular size of molecules the more conducive to increased nucleophilic reaction kinetics. Further still, the stronger nucleophile may promote faster and more efficient degradation of PFAS. For example, alkoxides compared to their thiolate counterparts may experience slower kinetics in degradation reactions due to a generally lower nucleophilicity.

[0162] The degradation of a PFAS in the presence of a strong nucleophile may represent a typical bimolecular reaction in terms of reaction kinetics. The reaction kinetics may be modeled as first (1st) order if the concentration of the nucleophile is in excess compared to the PFAS. A reaction rate consta nt k may be calculated from the linear 1storder kinetics fitting. The 1storder reaction may be defined using equation (I):C = Coe~kt(I) wherein Cis the concentration of the PFAS measured at a given reaction time t, Cois the initial concentration of the PFAS at time zero, k is the reaction rate constant (or efficient). Thereaction rate constant k, has units of 1 / time (e.g., 1 / hour). Equation (I) may be rearranged to give equation (II):In A = -kt (II) co wherein C is the concentration of PFAS measured at a given reaction time t, Cois the initial concentration of the PFAS at time zero, k is the reaction rate constant. Equation (II) implies c that a plot of ln(— ) vs. t may fit into a linear relationship. The slop of the linear relationship o obtained from a linear fitting would give the value of the reaction rate constant k.

[0163] The degradation of a PFAS of the present disclosure may be of temperature dependence. A high dependence on temperature, may in turn imply a high value of activation energy (i.e., an energy barrier for the defluorination reaction to occur). The temperature dependence may be quantitively analyzed by the Arrhenius equation as defined by equation (HI):-Eg k = Ae RT (III) wherein k is the reaction rate constant (or efficient), A is the preexponentialfactor, Eais the activation energy (or energy barrier) of the reaction, R is the molar gas constant, 8.314 JK" 1mol-1, and Tis the reaction temperature in units of Kelvin. Equation (III) may be rearranged to give equation (IV):wherein k is the reaction rate constant (or efficient), A is the preexponentialfactor, Eais the activation energy (or energy barrier) of the reaction, R is the molar gas constant, 8.314 JK" 1mol-1, and T is the reaction temperature. Equation (IV) implies that a plot of ln(k) vs. - may fit into a linear relationship. The slop of the linear relationship obtained from a linear fitting would give the value of the activation energy of the reaction Ea.

[0164] A reaction progress of the present disclosure may be tracked using nuclear magnetic resonance (NMR). An integral area of NMR peaks may be used to determine the concentration of a chemical (ions or molecules) being measured. This method relies on a principle that peak intensity or area is proportional to an analyte concentration, thus a linear relationship that serves as a calibration curve may be developed. The reaction progress of a defluorination reaction may accordingly be quantified using fluorine-19 nuclear magnetic resonance (19F- NMR) measurements to quantify the amount of free fluoride ions in the reaction.

[0165] During a defluorination reaction, the reaction solution may continually change regarding the concentration of an orga nofluorine compound a nd a nucleophile, as well as the pH, ionic strength and other characteristics of the solution. Therefore, a calibratio n curve established under fixed conditions cannot be directly applied for the quantitative ana lysis of fluorine ions in real reaction samples. Standard addition method, which is typical in analytical chemistry used to accurately determine the concentration of an analyte within complex samples, especially where matrix effects could interfere with results, may be used. The procedure may proceed by measuringthe initial response (here the fluoride ion peakaround -122 ppm using19F-NMR analysis) of the sample containing the unknown concentration of fluoride ions. Subsequently, known concentrations of fluoride ion, which may be added to the solution as NaF, may be added incrementally to separate portions of the sample. It may be appropriate, after each addition, to measure the19F NMR spectrum multiple times, to give an averaged value of an integral area underthe fluoride ion peak. This approach may effectively account for any interference from a sample matrix, allowing for a more accurate determination of fluoride ion in the solution at a given time within a defluorination reaction compared to a total fluorine initially present from a starting concentration of PFAS. This measurement may yield a fluoride recovery efficiency (%), by plotting the co ncentration of fluoride ions at a given time over the total initial fluorine present against the time of a reaction. The fluoride recovery efficiency may be used to assess the effectiveness of a particular reagent for the defluorination and degradation of a PFAS.EXAMPLES

[0166] Example 1: Defluorination and Degradation of Perfluorooctanoic Acid (PFOA)

[0167] Exemplary Reactions with PFOA

[0168] Scheme 1

[0169] The nucleophiles: sodium methane thiolate, sodium ethane thiolate, sodium amide, sodium methoxide, and sodium ethoxide were reacted in the presence of perfluorooctanoic acid (PFOA) in a molar ratio of 30:1, nucleophile to PFOA as shown in Scheme 1. Further testing included reacting PFOA with the reactants hydrazine and 1,8- diazabicyclo[5.4.0]undec-7-ene (DBU) in molar excess.

[0170] Two methods of reactions for the degradation of PFOA were performed. The first refers to the right proceeding reactions in Scheme 1 used HPLC -grade dimethyl sulfoxide (DMSO) as the solvent, which may contain trace amounts of water. The nucleophiles used in this first set of reactions could additionally or alternatively contain trace amounts of other reactants, for example, a 95% amide nucleophile may contain a trace amount of NaOH. Without wishing to be bound bytheory, the trace amounts of water within HPLC -grade DMSO or the trace amount of NaOH within reactants may cause the reaction of PFOA with a hydroxide ion (OH ) to form trifluoroacetic acid (TFA) as an intermediate. The slow degradation from TFA may limit the overall fluoride (F ). However, nucleophiles such as ethane thiolate and methane thiolate are weak bases and do not react with water to produce hydroxide which may eliminate TFA formation. Therefore, thiolate nucleophiles may not need a fully anhydrous reaction environmentfor best reaction efficiency. The second method for the degradation of PFOA using various nucleophiles, as discussed herein, proceeded usinganhydrous DMSO as a solvent and around 99% amide nucleophiles as a reactant as referred to the left proceeding reactions in Scheme 1.

[0171] For the first method, as shown in the right proceeding reactions of Scheme 1, i n a glass pressure tube, 95% sodium methane thiolate (0.127 g, 1.85 mmol), 95% sodium ethane thiolate (152 mg, 1.81 mmol), 95% sodium amide (70.6 mg, 1.81 mmol), 99% sodium amide (71 mg, 1.82 mmol) 99% sodium methoxide (98 mg, 1.81 mmol), or sodium ethoxide (123 mg, 1.81 mmol) was dissolved in 3 mL of anhydrous or HPLC -grade DMSO dimethyl sulfoxide (DMSO) with a heat gun. In a subsequent step, the DMSO was cooled down to room temperature, followed by the addition of PFOA (25 mg, 0.0604 mmol) to the tube forming a mixture. The mixture was then sonicated for 60 seconds. A 200 pL aliq uot was taken from the mixture and diluted into 400 pLof deuterated dimethyl sulfoxide (DMSO-d6) solvent and used as the t = 0 a liquot for fluorine-19 nuclear magnetic resonance (19F-NMR) measurement. The remaining mixture was heated in an oil bath for 24-72 hours at a single temperature in the range of 28-150 °C with 400 RPM stirring. To prevent overpressure, the glasstube was sealed with a screw-cap. To monitor reactions over time, two methods of NMR monitoring using a 400MHz machine were performed: an aliquot method and an evaporation method. First, the aliquot method included a 200 pL aliquot was taken by micropipette at a certain point of reaction time and prepared for19F-NMR measurement. The measurements were taken using both DMSO-d6, for analyzing PFAS and degradation intermediates, and D2O, for analyzing fluoride ions formed. For the evaporation method, the DMSO reaction solvent was evaporated at 160°C undera N2flow to form a residue when the reaction had concluded. The residue was redissolved in water, and next was diluted into D2O for19F-NMR analysis of fluoride ions.

[0172] The nucleophile hydrazine was reacted in the presence of PFOA in a molar ratio of 30:1 and 150:1, nucleophile to PFOA. In a glass pressure tube, hydrazine (0.58 mL, 18.1 mmol) and PFOA (50 mg, 0.12 mmol) were added to 3 mL of HPLC -grade DMSO. The mixture was then sonicated for 60 seconds. A 200 pL a liquot was taken from the mixture and diluted into 400 pL of DMSO-d6and used as the t = 0 aliquot for19F-NMR measurement. The remaining mixture was heated in an oil bath for 24-48 hours at 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain point of reaction time and prepared for 19F-NMR measurement.

[0173] The strong base and weak nucleophile l,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was reacted in the presence of PFOA in a molar ratio of 30:1, strong base to PFOA. In a glass pressure tube, DBU (1.1 mL, 7.2 mmol) and PFOA (100 mg, 0.24 mmol) were added to 3 mL of HPLC -grade DMSO or DMSO / water (8:1). The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of DMSO-d6and used as the t = 0 aliquot for19F-NMR measurement. The remaining mixture was heated in an oil bath for 24-48 hours at 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain point of reaction time and prepared for19F-NMR measurement.

[0174] For the second method, as shown in the left proceeding reactions of Scheme 1, the defluorination and degradation of PFOA were carried out in anhydrous DMSO solution with 95% sodium methane thiolate, 95% sodium ethane thiolate, 99% sodium amide, 99% sodium methoxide, 96% sodium ethoxide in excess relative to PFOA at a molar ratio of 30:1. The same reactant amounts and reaction conditions where similar to the HPLC-grade DMSO as described above.

[0175] The nucleophile sodium amide was reacted in the presence of PFOA. In a glass pressure tube, 99% sodium amide (71 mg, 1.82 mmol) and PFOA (25 mg, 0.061 mmol) were added to 3 mL of anhydrous DMSO. The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of DMSO-d6and used as the t = 0 aliquot for19F-NMR measurement. The remaining mixture was heated in an oil bath for 24 hours at 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions overtime, a 200 pL aliquot was taken by micropipette at certain point of reaction time and prepared for19F-NMR measurement.

[0176] Reaction Degradation Progression of PFOA

[0177] FIG. 2 shows the reaction progress of perfluorooctanoic acid (PFOA) with sodium methane thiolate at 150 °C as described above. The samples tested 200 pL aliquot taken at various times from O to 30 minutes and tested using19F-NMR in HPLC-grade DMSO-d6with a 400 MHz instrument. FIG. 3 shows the reaction progress of PFOA with sodium methane thiolate at 130 °C as described above. The samples tested 200 pL aliquot taken at various times from 0 to 180 min and tested using19F-NMR in HPLC-grade DMSO-d6. FIG. 4 shows the reaction progress of PFOA with sodium methane thiolate at 110 °C as described above. The samples tested 200 pL aliquot taken at various times from Oto 10 h and tested using19F-NMRin HPLC -grade DMSO-d6. FIG. 5 shows the reaction progress of PFOA with sodium ethane thiolate at 110 °C as described above. The samples tested 200 pL aliquot taken at various times from O to 24 h and tested using19F-NMR in HPLC -grade DMSO-d6. As shown in FIGS. 2- 5, the original PFOA peaks decreased when both reagents were used in DMSO-d6. When using methane thiolate, the decrease in the original peaks was accompanied by new peakformation at -55 ppm in the19F-NMR spectrum was used in DMSO-d6after 30 minutes. The fluoride ions generated from the degradation are not soluble in DMSO-d6but are soluble in D2O. When the same sample was measured in D2O, strong Fluoride peaks were detected at -121 ppm, which may suggest that the degradation products are primarily fluoride ions, likely due to the cleavage of the C-F bonds as shown in FIG. 1. This implies that the two nucleophiles, sodium methane thiolate and sodium ethane thiolate, used in the experiment effectively broke the C-F bonds, mineralizing PFOA into fluoride ions within the testing time frame at 110 °C. Running the reaction at elevated temperature will further expedite the process of mineralization. Interestingly, the degradation rate of methane thiolate i s about 34% faster than that of ethane thiolate, more on the reaction rate constant is explained below. This is consistent with the smaller molecular size of methane thiolate, which may be more conducive to nucleophilic reaction kinetics.

[0178] FIGS. 6-8 show the reaction progress of PFOA with sodium amide at 150°C, 130°C, and 110°C as described above. The samples tested 200 pL aliquot taken at various times from Oto 24 hours and tested using19F-NMR in HPCL-grade DMSO-d6with a 400 MHz instrument. Sodium amide caused rapid degradation of the original PFOA signal, with the characteristic TFA peak at -73.6 ppm appearing within 10 minutes. By 24 hours, the fluorine19F-NMR spectrum showed multiple peaks, including TFA and other products, which may suggest the formation of additional byproducts as the reaction progressed. PFOA peaks completely disappeared within 60 minutes when the reaction was carried out at 150 °C, accompanied by the appearance of a small fluorine peak at -57 ppm and the characteristic peak of TFA started appearingat -73.6 ppm. In contrast, at 130 °C and 110 °C, the PFOA peaks disappeared after approximately 1 h and 5 h, respectively Based on these results, amide may degrade PFOA differently from methane thiolate and ethane thiolate as shown in FIGS. 2-5, which results in the formation ofonlyfluoride ions. Defluorination ofTFA is relatively slower underthe same reaction conditions. This relative persistence of TFA may retard the full defluorination ofPFOA.

[0179] FIG. 9 shows the reaction progress of perfluorooctanoic acid (PFOA) with sodium methoxide at 110 °C as described above. The samplestested 200 pL aliquot taken at various times from 0 to 24 hours and tested using19F-NMR in HPLC -grade DMSO-d6with a 400 MHz instrument. The original PFOA signal degraded, and the TFA peak started appearing at -73.6 ppm as well as other byproducts. Other analogues of alkoxide, for example, ethoxide, may be even less effective at PFOA degradation and the largerthe molecularsize ofthe reactant may be unfavorable for nucleophilic reaction with the PFAS molecules.

[0180] The two most efficient nucleophiles, methane thiolate and sodium amide, were investigated further in various reaction temperatures. FIGS. 10-11 show the reaction progress of PFOA with sodium methane thiolate and sodium amide respectively at 28 °C as described above. The samples tested 200 pLaliquot taken at va rious times from Oto 72 hours and tested using19F-NMR in HPCL-grade DMSO-d6with a 400 MHz instrument. FIGS. 12-13 show the reaction progress of PFOA with sodium methane thiolate and sodium amide respectively at 60 °C as described above. The samplestested 200 pL aliquot taken at various times from 0 to 72 hours and tested using19F-NMR in HPCL-grade DMSO-d6with a 400 MHz instrument. FIGS. 14-15 show the reaction progress of PFOA with sodium methane thiolate and sodium amide respectively at 85 °C as described above. The samples tested 200 pL aliquot taken at various times from 0 to 72 hours and tested using19F-NMR in HPCL-grade DMSO-d6with a 400 MHz instrument. Lower reaction temperatures, such as 28 °C and 60 °C, showed slower degradation of PFOA compared to the same reaction when run at 110 °C as described above. After 72 hours of the reaction only small portions of the PFOA were shown to degrade as evident by the change in peaks over time for the temperature runs below 85°C. The temperature dependance implies that the degradation of PFOA has a high value for activation energy. The activation energy is an energy carrier for the defluorination reaction to occur.

[0181] FIGS. 14-15 show the reaction progress of PFOA with sodium methane thiolate and sodium amide respectively at 85 °C as described above. The samples tested 200 pL aliquot taken at various times from 0 to 72 hours and tested using19F-NMR in HPCL-grade DMSO-d6with a 400 MHz instrument. Degradation was more significant after 72 hours compared to the same experiments at lowertemperatures, (e.g. 28 °C and 65 °C). The overall degradation of PFOA at 85 °C was still less efficient compared to the degradation at 110 °C. The data at 85 °C therefore indicate that an optimal temperature for the reactions may be greater than 85C.

[0182] FIG. 16 shows the reaction progress of PFOA with hydrazine in a 150:1 hydrazine to PFOA ratio at 110 °C as described above. The samples tested 200 pL aliquot taken at times 0 and 24 hours and tested using19F-NMR in HPLC -grade DMSO-d6with a 400 MHz instrument, significant degradation of PFOA was observed as demonstrated by the dramatic decrease (more than 90%) in the original19F NMR peaks of PFOS. The peak decrease may imply efficient decarboxylation of PFOA. The decrease in the PFOA peaks were accompanied bythe increase in peaks corresponding to lH-perfluoro-heptane.

[0183] FIG. 17 shows the reaction progress of PFOA with strong base and weak nucleophile l,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) at 110 °C in DMSO as described above. The samples tested 200 pL aliquot taken at times 0 and 48 hours and tested using19F-NMR in HPLC -grade DMSO-d6with a 400 MHz instrument. FIG. 18 shows the reaction progress of PFOA with strong base and weak nucleophile l,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) at 110 °C in 8:1 DMSO / water as described above. The samples tested 200 pL aliquot taken at times 0, and 24 hours and tested using19F-NMR in HPLC -grade DMSO-d6with a 400 MHz instrument. There was degradation observed in FIGS. 17-18 as demonstrated by the dramatic decrease in the original19F-NMR peaks of PFOA. The peak decrease may imply efficient decarboxylation of PFOA. Accompanying the degradation of PFOA, new byproducts such as 1H -perfluoro- heptane formed as evidenced by the appearance of multiple peaks in the19F-NMR spectrum. The reaction showed clearer peaks and fewer byproducts formed when the solvent used was 8:1 DMSO / water as shown in FIG. 18. The difference between FIG. 17 and FIG. 18 maysuggest that the addition ofwater may influence the reaction pathway due to the change in solubility of reaction intermediates.

[0184] A summary of the degradation of PFOA at 110 °C with the various reactants as measured in HPLC-grade DMSO-d6is found in Table 1. The degradation rate and fluoride ion (F ) recovery are further described herein.

[0185] Table 1

[0186] FIG. 19 showsthe reaction progress of perfluorooctanoic acid (PFOA) with 95% sodium methane thiolate at 110 °C as described above. The samples tested 200 pL aliquot taken at various times from Oto 24 h and tested using19F-NMR in anhydrous DMSO-d6with a 400 MHz instrument. FIG. 20 shows the reaction progress of PFOA with sodium ethane thiolate at 110 °C as described above. The samples tested 200 pL aliquot taken at varioustimesfrom 0 to 24 h and tested using19F-NMR in anhydrous DMSO-d6. FIG. 21 shows the reaction progress of PFOA with sodium ethoxide 96% at 110 °C as described above. The samples tested 200 pL aliquot taken at varioustimesfrom 0 to 24 h and tested using19F-NMR in anhydrous DMSO- d6. FIG. 22 shows the reaction progress of PFOA with 99% sodium methoxide at 110 °C as described above. The samplestested 200 pL aliquot taken at various timesfrom Oto 24 h and tested using19F-NMR in anhydrous DMSO-d6.

[0187] FIGS. 23-29 showthe reaction progress of PFOA with 99% sodium amide in anhydrous DMSO at 150°C, 130°C, 110°C, 85°C, 60°C, and 28°C tested in anhydrous DMSO-d6as described above. The reaction of PFOA with 99% sodium amide in 99.9% anhydrous DMSO resulted in complete degradation and defluorination within 15 min at 150 °C and within 60 min at 130 °C. At 110 °C, complete degradation was achieved after 7 hours. When the same reaction was conducted at 85 °C, full degradation required approximately 3 days. In contrast, no significant degradation or defluorination was observed at 28 °C or 60 °C, highlighting the importance of elevated temperatures for effective C-F bond cleavage in PFOA under these conditions.

[0188] FIGS. 30-32 showthe reaction progress of PFOA with 99% sodium methane thiolate in anhydrous DMSO at 130°C, 85°C, and 60°C tested in anhydrous DMSO-d6as described above.The reaction of PFOA with 95% sodium methane thiolate in anhydrous DMSO resulted in complete degradation and defluorination within 35 minutes at 130 °C and within 6 hours at 110 °C. When the same reaction was conducted at 85 °C, full degradation required approximately 3 days. In contrast, significantly slow degradation or defluorination was observed at 60 °C

[0189] A summary of the degradation of PFOA with the various reactants as measured in anhydrous DMSO-d6is found in Table 2. The degradation rate and fluoride ion (F ) recovery are further described herein.

[0190] Table 2

[0191] Reaction Kinetics of PFOA Degradation

[0192] The degradation of perfluorooctanoicacid (PFOA) as described in the reactions herein follow a first (1st) order reaction kinetics. The reaction kinetics may be modeled as 1storder since the concentration of the nucleophiles, for example sodium methane thiolate and sodium amide, are in excess (30:1 molar ratio) relativeto PFOA. The reaction rate constant k may be calculated. The 1storder reaction may be defined using equation (I):C = Coe~kt(I) where C is the concentration of PFOA measured at a given reaction time t, Cois the initial concentration of PFOA attime zero, k is the reaction rate constant (orefficient).The reactionrate constant k has unitsof l / time, for exam pie, the reaction rate constant may have the units of 1 / h. Equation (I) may be rearranged to give equation (II):In A = -kt (II) co wherein C is the concentration of PFOA measured at a given reaction time t, Cois the initial concentration of PFOA at time zero, k is the reaction rate constant. Equation (II) may imply c that a plot of ln(— ) vs. t may fit into a linear relationship. The slop of the linear relationship o obtained from a linear fitting would give the value of the reaction rate constant k.

[0193] FIG. 33 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium methane thiolate at 28 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0194] FIG. 34 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium amide at a reaction temperature of 28 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0195] FIG. 35 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium methane thiolate at a reaction temperature of 60 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using 19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0196] FIG. 36 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by 95 % sodium amide at a reaction temperature of 60 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0197] FIG. 37 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium methane thiolate at a reaction temperature of 85 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0198] FIG. 38 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium amide at a reaction temperature of 85 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0199] FIG. 39 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium methane thiolate at a reaction temperature of 110 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0200] FIG. 40 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium amide at a reaction temperature of 110 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0201] FIG. 41 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium methane thiolate at a reaction temperature of 130 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0202] FIG. 42 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium amide at a reaction temperature of 130 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0203] FIG. 43 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium methane thiolate at a reaction temperature of 150 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0204] FIG. 44 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium amide at a reaction temperature of 150 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0205] FIG. 45 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium ethane thiolate at a reaction temperature of llO °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using 19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0206] FIG. 46 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by sodium methoxideat a reaction temperature of 110 °C in HPLC -grade DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 3.

[0207] Referring to Table 3, the reaction rate constant k of the degradation of PFOA by a nucleophile may increase with temperature in HPLC -grade DMSO. This implies that the reaction rate of a nucleophile with PFOA may be dependent on temperature.

[0208] Table 3

[0209] FIG. 47 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by 99% sodium amide at a reaction temperature of 60 °C in anhydrous DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 4.

[0210] FIG. 48 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by 99% sodium amide at a reaction temperature of 85 °C in anhydrous DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 4.

[0211] FIG. 49 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by 99% sodium amide at a reaction temperature of 110 °C in anhydrous DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 4.

[0212] FIG. 50 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by 99% sodium amide at a reaction temperature of 130 °C in anhydrous DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 4.

[0213] FIG. 51 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by 99% sodium amide at a reaction temperature of 150 °C in anhydrous DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F- NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 4.

[0214] Referring to Table 4, the reaction rate constant k of the degradation of PFOA by various amounts of sodium amide may increase with temperature in anhydrous DMSO. This implies that the reaction rate of amide with PFOA may be dependent on temperature.

[0215] Table 4

[0216] FIG. 52 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by 99% sodium methane thiolate at a reaction temperature of 60 °C in anhydrous DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 5.

[0217] FIG. 53 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by 99% sodium methane thiolate at a reaction temperature of 85 °C in anhydrous DMSO. The concentration of the PFOA at a given time was determined by integration of peaksusing19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 5.

[0218] FIG. 54 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by 99% sodium methane thiolate at a reaction temperature of 110 °C in anhydrous DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 5.

[0219] FIG. 55 shows the 1storder kinetics fittingof the data obtained from the degradation of PFOA by 99% sodium methane thiolate at a reaction temperature of 130 °C in anhydrous DMSO. The concentration of the PFOA at a given time was determined by integration of peaks using19F-NMR. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature shown in Table 5.

[0220] Referring to Table 5, the reaction rate constant k of the degradation of PFOA by various amounts of sodium methane thiolate may increase with temperature. This implies that the reaction rate of methane thiolate with PFOA may be dependent on temperature.

[0221] Table 5

[0222] Reaction Kinetics of PFOA Degradation

[0223] The temperature dependence observed can be quantitatively analyzed by Arrhenius equation as defined by equation (III):~gq k = Ae RT (III) wherein k is the reaction rate constant (or efficient), A is the preexponentialfactor, Eais the activation energy (or energy barrier) of the reaction, R is the molar gas constant, 8.314 JK" 1mol-1, and Tis the reaction temperature in units of Kelvin. Equation (III) may be rearranged to give equation (IV):wherein k is the reaction rate constant (or efficient), A is the preexponentialfactor, Eais the activation energy (or energy barrier) of the reaction, R is the molar gas constant, 8.314 JK" 1mol-1, and T is the reaction temperature. Equation (IV) implies that a plot of ln(k) vs. - mayfit into a linear relationship. The slop of the linear relationship obtained from a linear fitting would give the value of the activation energy of the reaction, Ea.

[0224] FIGS. 56 and 57 show the fitting of equation (IV) for the degradation of PFOA with sodium methane thiolate and sodium amide respectively underthree different temperatures, 60 °C, 85 °C, 110 °C, and 150 °C using HPLC -grade DMSO as a rection solvent. The resulting 1 graphs plot ln(k) vs. - with the temperature Tin units of Kelvin. The value of the reaction rate constant kfor 28 °C was not included in the Arrhenius equation fitting as the value may not be as reliable; within the experimental time frame of 72 hours, the concentration of PFOA decreased by around 2% therefore the reaction rate may be too slow for an accurate measurement. The fitting results of equation (IV) as shown in FIGS. 56 and 57 yield an activation energy Eaof 116.5 kJ / mol for sodium methane thiolate and 106.1 kJ / mol for sodium amide. These values are smaller and are contrasted with the activation energy Eafor the defluorination of PFOA by sodium hydroxide at 146 kJ / mol. The lower values of activation energy Eaindicate that sodium thiolate and sodium amide may be stronger nucleophiles compared to sodium hydroxide, thus enabling faster defluorination for PFAS.

[0225] Similarly, the fitting of equation (IV) for the degradation of PFOA with sodium methane thiolate and sodium amide using anhydrous DMSO as a reaction solvent are shown in FIGS. 58 and 59, respectively. The fitting results of equation (IV) as shown in FIGS. 56 and 57 yield an activation energy Eaof 131.4 kJ / mol for sodium methane thiolate and 125.8 kJ / mol for sodium amide. These activation energy values may imply that the amide is a slightly stronger nucleophile under the same reaction conditions, yielding faster reaction kinetics at the same temperature.

[0226] Fluoride Recovery from PFOA Degradation

[0227] The integral area of NMR peaks may be used to determine the concentration of a chemical being measured as an analyte. This relationship relies on the principle that peak intensity or peak area is proportional to the analyte concentration, creating a linear relationship that serves as a calibration curve. To verify this principle,19F-NMR measurements were executed with a series of solutions spiked with varying concentration of fluoride (F ) ions. Referring to FIG. 60, a linear calibration curve was generated by plotting the integral area of fluoride ion peak at -122 ppm in the19F NMR spectrum as a function of the spiked concentrations of sodium fluoride. The spiked concentration was in the range of 0 to 60 mM.The linearity of the plot may imply the feasibility of using19F NMR spectrometry for the quantitative analysis of fluoride ions produced in the defluorination reactions described herein.

[0228] During the defluorination process, the reaction solution may continually change with time regardingthe concentration of PFAS and nucleophile, pH, ionicstrength and potentially other metrics of the solution. Quantitative analysis of fluoride ions was performed using standard addition method for more accurate measurements. FIGS. 61-64 show standard addition measurements applied tothe analysis offluoride ions generated aftera 24 h reaction at 110 °C of PFOA with four nucleophiles, sodium methane thiolate, sodium ethane thiolate, sodium amide, and sodium methoxide, respectively. The concentration values marked represent the fluoride concentrations in the NMR solution, which are diluted 6X from the reaction solution of the four nucleophiles. The total fluorine available from the initial PFOA concentration was 303 mM, 318 mM, 304.3 mM, and 333.8 mM, for the reaction solution with sodium methane thiolate, sodium ethane thiolate, sodium amide, and sodium methoxide, respectively, when reacted in HPLC -grade DMSO. FIGS. 61-64 all provide a high level of linearity of fitting, enabling reliable determination of fluoride ion concentration.

[0229] Referring now to FIG. 65, using the module from the standard addition measurements, the amount of fluoride ion calculated may then be compared to the total fluorine initially present from the starting concentration of PFOA, yielding the fluoride recovery efficiency (%) at varying reaction times. FIG. 65 shows the fluoride recovery efficiency (%) dependent on time of the reaction of the degradation of PFOA with four nucleophiles sodium methane thiolate (CH3SNa), sodium ethane thiolate (C2H5SNa), sodium amide (NH2Na), and sodium methoxide (CH3ONa), respectively, when reacted in HPLC-grade DMSO. The results of FIG. 65 are shown in Table 6.

[0230] Table 6

[0231] After 24 hours of reaction, 98.4% fluoride recovery was achieved for the nucleophile sodium methane thiolate. The level of fluoride recovery for sodium methane thiolate may reasonably suggest complete defluorination of PFOA. A recovery efficiency of 92.4% was achieved for sodium ethane thiolate under the same condition, lower than that of sodium methane thiolate, which is consistent with the weaker nucleophilicity of sodium ethane thiolate due to its increasing molecular size. The recovery obtained for sodi um methoxide is even lower, 86.9%, which may be attributed to the generally lower nucleophilicity of alkoxides compared to their thiolate counterparts.

[0232] After 24 hours of reaction, 92% fluoride recovery was achieved for the nucleophile sodium amide when calculating using the fluoride ion measurement. The other mineralized product of PFOA degradation using sodium amide was trifluoracetic acid (TFA). TFA is considered a non-PFAS compound by the EPA, therefore it may be useful to includeTFA as a defluorinated product. FIG. 66 shows a linearcalibration curve by standard addition method to determine the concentration of TFA in the degradation reaction of PFOA. The concentration values marked in FIG. 66 represent the fluoride concentrations in the NMR solution, which are diluted 6X from the reaction solution of sodium amide in HPLC -grade DMSO. The total fluorine available from the initial PFOA concentration was 304.3 mM. The quantitative analysis of TFA was conducted by measuring its characteristic19F-NMR peak at - 73.6 ppm. Usingthe same standard addition method as used forthe measurement of fluoride ion, the concentration of TFA was quantified as 0.57 mM after 24 h of reaction, which is equivalent of 3.4% fluoride recovery. In combination with the 91.9% recovery as measured directly from the fluoride ion, this would give a total fluoride recovery of 95.3%; this value is close to the level obtained for sodium methane thiolate.

[0233] FIGS. 66-70 show linearcalibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of PFOA with five different nucleophiles, sodium methane thiolate, sodium ethane thiolate, sodium amide, sodium ethoxide, and sodium methoxide, after 24 h of reaction at 110 °C in anhydrous DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the 5 nucleophiles. The total fluorine available from the initial PFOA concentration was 302.2 mM, 314.2 mM, 304.3 mM, 302.6 and 303.1 mM, for the reaction solution with sodium methane thiolate,sodium ethane thiolate, sodium amide, sodium ethoxide, and sodium methoxide, respectively.

[0234] FIG. 71 shows the fluoride recovery efficiency (%) obtained for the reaction of PFOA with the five different nucleophiles (sodium methane thiolate, sodium ethane thiolate, sodium amide, sodium ethoxide, and sodium methoxide) at varying reaction times in anhydrous DMSO at 110 °C. The data from FIG. 71 is further shown in Table 7. The lower fluoride recovery observed for sodium methoxide is largely due to the formation of TFA and other fluorine-containing by-products that are slow to be defluorinated.

[0235] Table 7

[0236] Example 2: Defluorination and Degradation of Perfluorononanoic Acid (PFNA)

[0237] Scheme 2

[0238] The nucleophiles sodium methane thiolate and sodium amide were reacted in the presence of perfluorooctanoic acid (PFNA) in a molar ratio of 30:1, nucleophile to PFNA as shown in Scheme 2. In a glass pressure tube, sodium methane thiolate (0.133 g, 1.94 mmo l), or sodium amide (75 mg, 1.94 mmol) was dissolved in 3 mL of HPLC -grade dimethyl sulfoxide (DMSO) with a heat gun. In a subsequent step, the DMSO was cooled down to room temperature, followed by the addition of PFNA (30 mg, 0.0646 mmol) to the tube form ing a mixture. The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pLof deuterated dimethyl sulfoxide (DMSO-d6) solvent and used as the t = 0 a liquot for fluorine-19 nuclear magnetic resonance (19F-NMR) measurement. The remaining mixture was heated in an oil bath for 24 hours at a temperature of 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain point of reaction time and prepared for19F-NMR measurement.

[0239] FIG. 72 shows the reaction progress of PFNA with sodium methane thiolate at 110 °C in HPLC -grade DMSO as described above. The samples tested 200 pL aliquot taken at various times from 0 to 24 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument. No fluorine peaks were observed in DMSO-d6 after 24 hours, likely indicating complete defluorination and degradation of PFNA. The sodium methanethiolatewas able to effectively break the C-F bonds mineralizing PFNA into fluoride ions within the testing time fra me at 110 °C.

[0240] FIG. 73 shows the reaction progress of PFNA with 95% sodium amide at 110 °C in HPLC- grade DMSO as described above. The samples tested 200 pL aliquot taken at various times from 0 to 24 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument. The original PFNA signal degraded, and the characteristic peak of trifluoroacetic acid (TFA) started appearingat -73.6 ppm. At 24 hours, no fluorine was detected and only TFA peaks remained.Therefore, sodium amide degrades PFNA differently from methane thiolate, which results in the formation of only fluoride ions.

[0241] FIGS. 74 and 75 show standard addition measurements applied to the analysis of fluoride ions generated after a 24 hours reaction at 110 °C of PFNA with two nucleophiles, sodium methane thiolate and sodium amide in HPLC -grade DMSO, respectively. The concentration values marked represent the fluoride concentrations in the NMR solution, which are diluted 6X from the reaction solution of the two nucleophiles. The total fluorine available from the initial PFNA concentration was 342 mM and 319.8 mM, for the reaction solution with sodium methane thiolate and sodium amide, respectively. FIGS. 74 and 75 all provide a high level of linearity of fitting, enabling reliable determination of fluoride ion concentration.

[0242] Referring now to FIG. 76, using the module from the standard addition measurements, the amount of fluoride ion calculated may then be compared to the total fluorine initially present from the starting concentration of PFNA, yielding the fluoride recovery efficiency (%) at varying reaction times. FIG. 76 shows the fluoride recovery efficiency (%) dependent on time of the reaction of the degradation of PFNA with four nucleophiles sodium methane thiolate (CH3SNa), and sodium amide (NH2Na), respectively. The results of FIG. 76 are also shown in Table 8.

[0243] Table 8

[0244] After 24 hours of reaction, 93% fluoride recovery was achieved for the nucleophile sodium methane thiolate. The level of fluoride recovery for sodium methane thiolate may reasonably suggest complete defluorination of PFNA. A recovery efficiency of 89% was achieved for sodium amide underthe same condition, lower than that of sodium methane thiolate as shown in FIG 76.

[0245] After 24 hours of reaction, 89% fluoride recovery was achieved for the nucleophile sodium amide when calculating usingthe fluoride ion measurement. The other mineralizedproduct of PFNA degradation using sodium amide was trifluoracetic acid (TFA). FIG. 77 shows a linear calibration curve by standard addition method to determine the concentration of TFA in the degradation reaction of PFNA. The concentration values marked in FIG. 77 represent the fluoride concentrations in the NMR solution, which are diluted 6X from the reaction solution of sodium amide. The total fluorine available from the initial PFNA concentration was 319.8 mM. The quantitative analysis of TFA was conducted by measuring its characteristic19F- NMR peak at -73.6 ppm. Using the same standard addition method as used for the measurement of fluoride ion, the concentration of TFA was quantified as 0.75 mM after 24 h of reaction, which is equivalent of 4.2% fluoride recovery. In combination with the 88.7% recovery as measured directly from the fluoride ion, this would give a total fluoride recovery of 92.9%.

[0246] Same reactions with PFNA and sodium methane thiolate were carried out in anhydrous DMSO and 92% fluoride recovery was obtained after 24 h following the "evaporation method" as described herein.

[0247] The defluorination and degradation of PFNA was further reacted in an anhydrous DMSO solution with 99% sodium amide, in excess relative to PFNA at a molar ratio of 30:1. In a glass pressure tube, 99% sodium amide (64 mg, 1.61 mmol) was dissolved in 3 mL of anhydrous dimethyl sulfoxide (DMSO) with a heat gun. In a subsequent step, the DMSO was cooled down to room temperature, followed bythe addition of PFNA (25 mg, 0.054 mmol) to the tube forming a mixture. The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deuterated dimethyl sulfoxide (DMSO- d6) solvent and used as the t = 0 aliquot for fluorine-19 nuclear magnetic resonance (19F-NMR) measurement. The remaining mixture was heated in an oil bath for 24 hours at a temperature of 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by m icropipette at certain point of reaction time and prepared for19F-NMR measurement.

[0248] FIG. 78 shows the reaction progress of PFNA with 95% sodium amide at 110 °C in anhydrous DMSO as described above. The samples tested 200 pL aliquot taken at various times from O to 24 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument.

[0249] FIG. 79 shows the linear calibration curves created by standard addition method used to determine the concentration of F’ ion in the reaction solution of PFNA with 99% sodium amide after 24 h of reaction at 110 °C in anhydrous DMSO. The concentration values markedin FIG. 79 represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial PFNA concentration was 297.6 mM for the reaction solution with 99% sodium amide.

[0250] FIG. 80 shows the fluoride recovery efficiency (%) obtained for the reaction of PFNA with 99% NaNH2nucleophile in anhydrous DMSO at varying reaction times. The data is also shown in Table 9.

[0251] Table 9

[0252] The degradation of PFNA followed a similar pattern to that of PFOA, but the defluorination occurred at a slightly slower rate. This slower defluorination may be attributed to the longer carbon chain in PFNA compared to PFOA. 100% degradation and 97% fluoride recovery were achieved within 24 hours at 110 °C

[0253] Same reactions with PFNA and sodium amide were carried out in anhydrous DMSO and 96.7% fluoride recovery was obtained after 24 h following the "evaporation method" as described herein.

[0254] Example 3: Defluorination and Degradation of Perfluorobutanoic acid (PFBA)

[0255] Scheme 3CH3SNa, 48 hFF + CF,COO

[0256] The nucleophiles sodium methane thiolate and sodium amide were reacted in the presence of perfluorobutanoic acid (PFBA) in a molar ratio of 30:1, nucleophile to PFBA as shown in Scheme 3. In a glass pressure tube, sodium methane thiolate (0.161g, 2.3 mmol ) or sodium amide (90 mg, 2.3 mmol) was dissolved in 3 mL of HPLC -grade dimethyl sulfoxide(DMSO) with a heat gun. In a subsequent step, the DMSO was cooled down to room temperature, followed by the addition of PFBA (10 pL, 0.0766 mmol) to the tube forming a mixture. The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pLof deuterated dimethyl sulfoxide (DMSO-d6) solvent and used as the t = 0 a liquot for fluorine-19 nuclear magnetic resonance (19F-NMR) measurement. The remaining mixture was heated in an oil bath for 48 hours at a temperature of 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain point of reaction time and prepared for19F-NMR measurement.

[0257] FIG. 81 shows the reaction progress of PFBA with sodium methane thiolate at 110 °C as described above. The samples tested 200 pL aliquot taken at various times from 0 to 24 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument. No fluorine peaks were observed in DMSO-d6 after 48 hours, likely indicating complete defluorination and degradation of PFBA. The sodium methane thiolate was able to effectively break the C-F bonds mineralizing PFBA into fluoride ions within the testing time frame at 110 °C. The slower defluorination of PFBA may be due to its shorter chain length compared to PFOA of Example 1, affecting how the nucleophile interacts with the molecule. Short -chain perfluoroalkyl substances like PFBA may exhibit different reaction kinetics because the size of the PFAS might limit nucleophilic attack in certain regions of the molecule, slowing down the defluorination process compared to longer chains like PFOA, which can provide more accessible sites for nucleophilic attack.

[0258] FIG. 82 shows the reaction progress of PFBA with sodium amide at 110 °C as described above. The samples tested 200 pLaliquot taken at various times from Oto 24 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument. The original PFBA signal degraded, and the characteristic peakoftrifluoroaceticacid (TFA) started appearingat -73.6 ppm aswell as other unidentified fluorine-containing byproducts even after 48 hours. Longer reaction time or higher concentration of nucleophiles may be needed to expedite the defluorination of PFBA.

[0259] FIGS. 83 and 84 showsthe results of standard addition measurements used to quantify the fluoride ions (F“) generated after a 24-hour reaction of PFBA with two nucleophiles, CH3SNa and NH2Na, respectively. Using the same approach, the concentrations of F“ ions produced at different reaction times (0-48 h) were determined for each nucleophile. Thefluoride recoveries for both nucleophilesare summarized in Table 10 and Figure 85. After48 hours of reaction, CH3SNa achieved a fluoride recovery of 97.5%. For NH2Na, the fluoride recovery was 95.7% after 32 h. Notably, trifluoroacetic acid (TFA) was also detected as an additional mineralized product underthese reaction conditions; however, its concentration was below the quantifiable limit due to its very low yield.

[0260] Table 10

[0261] Same reactions with PFBA and sodium methane thiolate were carried out in anhydrous DMSO and 93% fluoride recovery was obtained after 24 h following the "evaporation method" as described herein.

[0262] The defluorination and degradation of PFBA were carried out in a n anhydrous DMSO solution with 99% NH2Na, in excess relative to PFBA at a molar ratio of 30:1. In a glass pressure tube, 99% sodium amide (90 mg, 2.3 mmol) was dissolved in 3 mL of 99.9% anhydrous DMSO with a heat gun. The above reaction mixture was cooled down at room temperature before PFBA was added (10 pL, 0.0766 mmol). The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deuterated DMSO solvent and used as the t = 0 aliquot for NMR measurement. The rest of mixture in the glass tube was heated in an oil bath for 24 hours at 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain point of reaction time, and prepared for NMR measurement. All the collected samples were subjected to19F NMR analysis using 400 MHz NMR instrumentation .

[0263] FIG. 86 shows the reaction progress of PFBA with 99% sodium amide at 110 °C in an hydrous as described above. The samples tested 200 pL aliquot taken at various times from 0 to 24 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument.

[0264] FIG. 87 shows the linearcalibration curve created by standard addition method used to determine the concentration of F" ion in the reaction solution of PFBA with 99% NaNH2after 9 h of reaction at 110 °C in anhydrous DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial PFBA concentration was 201 mM for the reaction solution with 99% NH2Na.

[0265] FIG. 88 shows the fluoride recovery efficiency (%) obtained for the reaction of PFBA with 99% NaNH2nucleophiles in anhydrous DMSO at varying reaction times. The data from FIG. 88 is also shown in Table 11. A complete degradation was achieved within 9 hours. Fluoride recovery was 100.6%

[0266] Same reactions with PFBA and sodium amide were carried out in anhydrous DMSO and 98.4% fluoride recovery was obtained after 24 h followingthe "evaporation method" as described herein.

[0267] Table 11

[0268]

[0269] Example 4: Defluorination and Degradation of GenX™

[0270] Scheme 4e

[0271] The nucleophiles sodium methane thiolate and sodium amide were reacted in the presence of an ammonium salt of hexafluoropropylene oxide dimer (GenX™) in a molar ratio of 30:1, nucleophile to GenX™ as shown in Scheme 4. In a glass pressure tube, sodiummethane thiolate (0.121 g, 1.73 mmol) or sodium amide (67 mg, 1.73 mmol) was dissolved in 3 mL of HPLC -grade dimethyl sulfoxide (DMSO) with a heat gun. In a subsequent step, the DMSO was cooled down to room temperature, followed by the addition of GenX™ (20 mg, 0.0576 mmol) to the tube forming a mixture. The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deuterated dimethyl sulfoxide (DMSO-d6) solvent and used as the t = 0 aliquot for fluorine-19 nuclear magnetic resonance (19F-NMR) measurement. The remaining mixture was heated in an oil bath for 48 hours at a temperature of 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions overtime, a 200 pL aliquot was taken by micropipette at certain point of reaction time and prepared for19F-NMR measurement.

[0272] FIG. 89 shows the reaction progress of GenX™ with sodium methane thiolate at 110°C in HPLC -grade DMSO as described above. The samples tested 200 pL aliquot taken at various times from 0 to 48 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument.

[0273] FIG. 90 shows the reaction progress of GenX™ with sodium amide at 110 °C in HPLC- grade DMSO as described above. The samples tested 200 pL aliquot taken at various times from 0 to 48 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument.

[0274] FIG. 91 shows the reaction progress of GenX™ with sodium methane thiolate at 150 °C in HPLC -grade DMSO as described above. The samples tested 200 pL aliquot taken at various times from 0 to 48 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument.

[0275] FIG. 92 shows the reaction progress of GenX™ with sodium amide at 150 °C in HPLC- grade DMSO as described above. The samples tested 200 pL aliquot taken at various times from 0 to 48 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument.

[0276] The reaction results were found significantly different from those of PFOA of Example 1. In case of CH3SNa, the degradation and defluorination process was very fast, and after 1 h, perfluoropropionic acid (PFPrA) was formed. Upon extending the reaction up to 48 h, there was no further short chaining, and PFPrA was identified as the final product. In case of NH2Na, slower defluorination occurred. The different reaction kinetics observed for GenX may be due to its different structure compared to PFOA of Example 1. GenX contains a -CF3group and an ether linkage in its backbone, which may make the molecule more resistant to nucleophilic attack compa red to the simpler structure of PFOA. The ether linkage can a Iso affect the overallstability and reactivity of the molecule, contributing to the slow release of fluoride and the eventual formation of PFPrA as a degradation product.

[0277] FIGS. 93 and 94 show the results used to determine the concentration of F" ion in the reaction solution of GenX with two different nucleophiles after 48 h of reaction at 110 °C in HPLC -grade DMSO. The concentration values marked in these figures represent the fluoride concentrations in HPLC -grade DMSO NMR solution, which are diluted 6x times from the reaction solution of the two nucleophiles. The total fluorine available from the initial GenX concentration was 211.2 mM, forthe reaction solution with CH3SNa, and NH2Na, respectively. After 48 hours of reaction at 110 °C, CH3SNa and NH2Na achieved a fluoride recovery of 57% and 65%, respectively.

[0278] FIGS. 95 and 96 show the results used to determine the concentration of F" ion in the reaction solution of GenX with two different nucleophiles after 48 h of reaction at 150 °C in HPLC -grade DMSO. The concentration values marked in these figures represent the fluoride concentrations in HPLC -grade DMSO NMR solution, which are diluted 6x times from the reaction solution of the two nucleophiles. The total fluorine available from the initial GenX concentration was 211.2 mM, for the reaction solution with CH3SNa, and NH2Na, respectively The fluoride recoveries for both nucleophiles are summarized in Table 12.

[0279] Table 12

[0280] The different reaction kinetics observed for GenX™ compared to the reaction of PFOA of Example 1 is likely due to its different structure compared to PFOA. GenX™ contains a -CF3group and an ether linkage in the molecule's backbone, which may make the molecule more resistant to nucleophilic attack compa red to the simpler structure of PFOA. The ether linkage can also affect the overall stability and reactivity of the molecule, contributing to the slow release of fluoride and the eventual formation of PFPrA as a degradation product.

[0281] Same reactionswith GenX™ and sodium amide were carried out in anhydrous DMSO and 57.8% fluoride recovery was obtained after 24 h followingthe "evaporation method" as described herein.

[0282] The defluorination and degradation of Ge nX™ were carried out in an anhydrous DMSO solution with 99% NH2Na, in excess relative to PFBA at a molar ratio of 30:1. In a glass pressure tube, 99% sodium amide (67 mg, 1.73 mmol) was dissolved in 3 mL of 99.9% anhydrous DMSO with a heat gun. The above reaction mixture was cooled down at room temperature before GenXwas added (20 mg, 0.0576 mmol). The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deuterated DMSO solvent and used as the t = 0 aliquot for NMR measurement. The rest of mixture in the glass tube was heated in an oil bath for 48 hours at 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube were sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain point of reaction time, and prepared for NMR measurement. All the collected samples were subjected to19F NMR analysis using 400 MHz NMR instrumentation .

[0283] FIG. 97 shows the reaction progress of GenX™ with sodium amide at 110 °C in anhydrous DMSO as described above. The samples tested 200 pL aliquot taken at various times from O to 48 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument.

[0284] FIG. 98 shows the linear calibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of GenX with 99% NaNH2after 48 h of reaction at 110 °C in anhydrous DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial GenX concentration was 241.8 mM for the reaction solution with 99% NH2Na.

[0285] FIG. 99 shows the fluoride recovery efficiency (%) obtained for the reaction of GenX with 99% NaNH2nucleophiles in anhydrous DMSO at varying reaction times, with the data shown in Table 13.

[0286] Table 13

[0287] The degradation of GenX was slow with amide nucleophile when compared to PFOA.GenX contains a -CF3group and an ether linkage in its backbone, which may make the molecule more resistant to nucleophilic attack compared to the simpler structure of PFOA.The results show that 78% fluoride recovery was achieved after 24 hours. Propionic acid intermediate was persistent.

[0288] Same reactions with GenX™ and sodium amide were carried out in anhydrous DMSO and 86% fluoride recovery was obtained after 24 h following the "evaporation method" as described herein

[0289] Example 5: Defluorination and Degradation of 1H -perfluoroheptane (lH-PFHp)

[0290] Scheme 5CH3SNa. 3 hF + CF3COO

[0291] lH-Perfluoroheptane (lH-PFHp) was chosen to study as the molecule is the primary intermediate produced from the decarboxylation of PFOA. The nucleophiles sodium methane thiolate and sodium amide were reacted in the presence of lH -PFHp in a molar ratio of 30:1, nucleophile to lH-PFHp as shown in Scheme 5. In a glass pressure tube, sodium methane thiolate (0.147 g, 2.1 mmol) or sodium amide (82 mg, 2.1 mmol) was dissolved in 3 mL of HPLC -grade dimethyl sulfoxide (DMSO) with a heat gun. In a subsequent step, the DMSO was cooled down to room temperature, followed by the addition of lH -PFHp (15 pL, 0.0699 mmol) to the tube forming a mixture. The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deute rated dimethyl sulfoxide (DMSO-d6) solvent and used as the t = 0 aliquot for fluorine-19 nuclear magnetic resonance (19F-NMR) measurement. The remaining mixture was heated in an oil bath for 24 hours at a temperature of 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain point of reaction time and prepared for19F-NMR measurement.

[0292] FIG. 100 shows the reaction progress of lH-PFHp with sodium methane thiolate at 110 °C as described above. The samplestested 200 pL aliquot taken at varioustimes from 0 to 3 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument. FIG. 100 shows 1H- PFHp analyzed in a 1:2 mixture of chloroform-d (CDCI3) and DMSO-d6as lH-PFHp is insoluble in DMSO. No fluorine peaks were observed in DMSO-d6 after 3 hours, likely indicating complete defluorination and degradation of lH-PFHp. The sodium methane thiolate was able to effectively break the C-F bonds mineralizing lH-PFHp into fluoride ions within the testingtime frame at 110 °C. A rate of degradation may be calculated for lH -PFHp in the presence of sodium methane thiolate at 110 °C of 100% degraded after 3 hours. The rate of the reaction may suggest that lH-PFHp, which lacks a carboxylic group compared to PFOA of Example 1, undergoes degradation faster than PFOA, for which the decarboxylation may be the rate limited step.

[0293] FIG. 101 shows the reaction progress of lH-PFHp with sodium amide at 110 °C as described above. The samples tested 200 pLaliquot taken at various times from Oto 24 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument. FIG. 101 shows lH-PFHp analyzed in a 1:2 mixture of chloroform-d (CDCI3) and DMSO-d6as lH-PFHp is insoluble in DMSO. The original lH-PFHp signal degraded, and the characteristic peak of trifluoroacetic acid (TFA) started appearing at -73.6 ppm. A rate of degradation may be calculated for 1H- PFHp in the presence of sodium amide at 110 °C of 98% degraded after 24 hours.

[0294] FIGS. 102 and 103 show the linear calibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of lH-PFHp with two different nucleophiles after 24 h of reaction at 110 °C in HPLC -grade DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the 2 nucleophiles. The total fluorine available from the initial lH-PFHp concentration was 294 mM, and 279.6 mM for the reaction solution with CH3SNa, and NH2Na, respectively.

[0295] FIG. 104 shows the I inear calibration curves created by standard addition method used to determine the concentration of TFA in the reaction solution of lH-PFHp with amide nucleophilesafter 24 h of reaction at 110 °C in HPLC -grade DMSO. The concentration values marked in this figure represent the fluoride concentrations in the NMR solution, which are diluted 6x from the reaction solution of NH2Na. The total fluorine available from the initial PFAS concentration was 279.6 mM. The quantitative analysis of TFA was conducted by measuring its characteristic19F NMR peak at -73.6 ppm.

[0296] The data of the total fluoride recovery (%) are further shown in Table 14.

[0297] Table 14

[0298] Same reactions with lH-PFHp and sodium amide were carried out in anhydrous DMSO and 96.2% fluoride recovery was obtained after 24 h followingthe "evaporation method" as described herein

[0299] The defluorination and degradation lH-PFHp were carried out in an anhydrous DMSO solution with 99% NH2Na, in excess relative to lH-PFHp at a molar ratio of 30:1. In a glass pressure tube, 99% sodium amide (82 mg, 2.1 mmol) was dissolved in 3 mL of 99.9% anhydrous DMSO with a heat gun. The above reaction mixture was cooled down at room temperature before lH-PFHp was added (15 pL, 0.0699 mmol). The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deuterated CDCI3solvent and used as the t = 0 aliquot for NMR measurement. The rest of mixture in the glass tube was heated in an oil bath for 5 hours at 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube were sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain point of reaction time, and prepared for NMR measurement. All the collected samples were subjected to19F NMR analysis using 400 MHz NMR instrumentation .

[0300] FIG. 105 shows the reaction progress of lH-PFHp with sodium methane thiolate at 110 °C in anyhrous DMSO as described above. Degradation of lH-PFHp by amide is very efficient; the reaction runsfast even at room temperature, with all the compounds degraded instantly (faster than the sample preparation time), although the complete recovery of fluoride ions takes a little longertime (up to 3 hours), indicatingthat some fluorine-containing byproducts are formed during the degradation and complete defluorination of these byproducts takes longer time.

[0301] FIG. 106 shows the linearcalibration curves created by standard addition method used to determine the concentration of F’ ion in the reaction solution of lH-PFHp with 99% NaNH2after 5 h of reaction at 110 °C in anhydrous DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial 1H- PFHp concentration was 321.6 mM for the reaction solution with 99% NH2Na.

[0302] FIG. 107 shows the fluoride recovery efficiency (%) obtained for the reaction of 1H-PFHp with 99% NaNH2nucleophiles in anhydrous DMSO at varying reaction times. The fluoride recovery data is further shown in Table 15.

[0303] Table 15

[0304] Same reactions with lH-PFHp and sodium amide were carried out in anhydrous DMSO and 8.6% fluoride recovery was obtained after 24 h following the "evaporation method" as described herein

[0305] Example 6: Defluorination and Degradation of Trifluoroacetic Acid (TFA) COO‘COO

[0306] T rifl uoroacetic acid (TFA) was chosen to study as the molecu le is a major produce from the defluorination of PFOA, PFNA, and PFBA of Examples 1-3 respectively. The nucleophiles sodium methane thiolate and sodium amide were reacted in the presence of TFA in a molar ratio of 30:1, nucleophile to TFA as shown in Scheme 6. In a glass pressure tube, sodium methane thiolate (0.274 g, 3.92 mmol) or sodium amide (153 mg, 3.92 mmol) was dissolved in 3 mL of HPLC -grade dimethyl sulfoxide (DMSO) with a heat gun. In a subsequent step, the DMSO was cooled down to room temperature, followed by the addition ofTFA (400 pL, 0.13 mmol) to the tube forming a mixture. The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deuterated dimethyl sulfoxide (DMSO-d6) solvent and used as the t = 0 aliquot for fluorine-19 nuclear magnetic resonance (19F-NMR) measurement. The remaining mixture was heated in an oil bath for 90 hours at a temperature of 110 °C with 400 RPM sti rring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions overtime, a 200 pL aliquot was taken by micropipette at certain point of reaction time and prepared for19F-NMR measurement.

[0307] FIGS. 108 and 109 show the reaction progress of TFA with sodium methane thiolate and sodium amide, respectively, at 110 °C in HPLC -grade DMSO as described above. Thesamples tested 200 pL aliquot taken at various times from O to 72 hours and tested using19F- NMR in DMSO-d6with a 400 MHz instrument. A significant decrease in fluorine signa I resulting in the mineralization of fluoride ions.

[0308] FIGS. 110 and 111 show the reaction progress of TFA with sodium methane thiolate and sodium amide, respectively, at 150 °C in HPLC -grade DMSO as described above. The samples tested 200 pL aliquot taken at various times from O to 24 hours and tested using19F- NMR in DMSO-d6with a 400 MHz instrument. A significant decrease in fluorine signa I resulting in the mineralization of fluoride ions.

[0309] FIG. 112 and 113 show the linear calibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of TFA with the two different nucleophiles after 24 h of reaction at 150 °C in HPLC -grade DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the 2 nucleophiles. The total fluorine available from the initial TFA concentration was 143.7 mM for the reaction solution with CH3SNa, and NH2Na, respectively.

[0310] The reaction rate constant (k) was determined for various reaction temperatures for sodium methane thiolate and sodium amide with TFA in HPLC-grade DMSO. The determination of the reaction rate constant (k) is explained in Example l. The results of the reaction rate constant are found in Table 16.

[0311] Table 16

[0312] FIG. 114 and 115 shows Arrhenius plots showing the relationship between I n ( k) and 1 / T for the degradation of TFA with sodium methane thiolate and sodium amide, respectively, in HPLC-grade DMSO. An explanation for the Arrhenius plots can be found in Example 1. Arrhenius linear fitting was obtained for both the two nucleophiles, CH3SNa and NH2Na,yielding an activation energy (Ea) of 114.2 kJ / mol for CH3SNa and 108.0 kJ / mol for NH2Na, respectively. These values are close to PFOA activation energy (104.2 kJ / mol for CH3SNa and 102.0 kJ / mol for NH2Na) of Example 1.

[0313] The defluorination and degradation TFA were carried out in an anhydrous DMSO solution with 99% NH2Na, in excess relative to TFA at a molar ratio of 30:1. In a glass pressure tube, 99% sodium amide (153 mg, 3.92 mmol) was dissolved in 3 mL of 99.9% anhydrous DMSO with a heat gun. The above reaction mixture was cooled down at room temperature before TFA was added (400 pL, 0.13 mmol). The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deuterated DMSO solvent and used as the t = 0 aliquot for NMR measurement. The rest of mixture in the glass tube was heated in an oil bath for 96 hours at 110 or 150 °C with 400 RPM stirri ng. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain point of reaction time, and prepared for NMR measurement. All the collected samples were subjected to19F NMR analysis using 400 MHz NMR.

[0314] FIGS. 116 and 117 show the reaction progress of TFA with 99% sodium amide at 110 °C and 150 °C, respectively, in anhydrous DMSO as described above. The samples tested 200 pL aliquot taken at various times from 0 to 96 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument.

[0315] FIG. 118 shows the linearcalibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of TFA with 99% Na NH2after 96 h of reaction at 110 °C in anhydrous DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial TFA concentration was 130.2 mM for the reaction solution with 99% NH2Na.

[0316] FIG. 119 shows linearcalibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of TFA with 99% Na NH2after 6 h of reaction at 150 °C in anhydrous DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial TFA concentration was 117.6 mM for the reaction solution with 99% NH2Na.

[0317] The fluoride recovery (%) for TFA with sodium amide in anhydrous DMSO was calculated for both reaction temperatures 110 °C and 150 °C as shown in Table 17.

[0318] Table 17

[0319] When the reaction was at 110 °C, the degradation was more than 90% and the fluoride recovery was 93%. In contrast, the reaction at 150 °C with NH2Na, the TFA signal completely disappeared within 3 hours of reaction. The fluoride recovery achieved was 99.5% when the reaction at 150 °C.

[0320] Same reactions with TFA a nd sodium amide were carried out in anhydrous DMSO a nd 95% fluoride recovery was obtained after 24 h following the "evaporation method" as described herein.

[0321] Example 7: Defluorination and Degradation of Perfluorooctane Sulfonic Acid (PFOSK)

[0322] Scheme 7

[0323] Sodium amide was reacted in the presence of perfluorooctane sulfonicacid potassium salt (PFOSK) in a molar ratio of 30:1, nucleophile to PFOSK as shown in Scheme 7. No significant reaction was observed. The ratio was adjusted to 100:1, nucleophile to PFOSK and reacted in anhydrous DMSO. In a glass pressure tube, 99% sodium amide (200 mg, 3.71 mmol) was dissolved in 3 mL of anhydrous dimethyl sulfoxide (DMSO) with a heat gun. In a subsequent step, the DMSO was cooled down to room temperature, followed by the addition of PFOSK (20 mg, 0.0372 mmol) to the tube forming a mixture. The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deuterated dimethyl sulfoxide (DMSO-d6) solvent and used as the t = 0 aliquot for fluorine-19 nuclear magnetic resonance (19F-NMR) measurement. The remaining mixture was heated in an oil bath for 96 hours at a temperature of 150 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions over time, a200 pL aliquot was taken by micropipette at certain point of reaction time and prepared for 19F-NMR measurement.

[0324] FIG. 120 shows the reaction progress of PFOSK with sodium amide at 150 °C as described above. The samples tested 200 pLaliquot taken at various times from Oto 90 hours and tested using19F-NMR in DMSO-d6with a 400 MHz instrument.

[0325] FIG. 121 shows linearcalibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of PFOSK with 99% Na NH2after 96 h of reaction at 150 °C in anhydrous DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial PFOSK concentration was 197.4 mM for the reaction solution with 99% NH2Na.

[0326] FIG. 122 shows the fluoride recovery efficiency (%) obtained forthe reaction of PFOSK with 99% NaNH2in anhydrous DMSO at varying reaction times, the data can be seen in Table 18.

[0327] Table 18

[0328] The fluoride recovery experiment was conducted over a time period of O hour to 96 hours using19F-NMR. A saturation point was observed between 72 hours and 96 hours. Partial degradation, <60%, and fluoride recovery, 27%, was observed. The low recovery and degradation are likely due to the ineffective interaction between PFOSK and nucleophiles at the tested ratio

[0329] Example 8: Defluorination and Degradation of Polyvinylidene Fluoride (PVDF)

[0330] Scheme 8

[0331] The nucleophiles sodium methane thiolate and sodium amide were reacted in the presence polyvinylidene fluoride (PVDF) (molar ratio calculations were based on the number of fluorine atoms in PVDF, considering its molecular weight of 600,000 g / mol), as shown in Scheme 8. In a glass pressure tube, sodium methane thiolate (0.434 g,6.2 mmol) or 95% sodium amide (243 mg, 6.2 mmol) was dissolved in 3 mL of HPLC -grade dimethyl sulfoxide (DMSO) with a heat gun. In a subsequent step, the DMSO was cooled down to room temperature, followed by the addition of PVDF (50 mg, 0.78 mmol) to the tube forming a mixture. The mixture was then sonicated for 60 seconds. A 100 pL aliquot was taken from the mixture and diluted into 500 pL of deuterium oxide (D2O) solvent and used as the t = 0 aliquot for fluorine-19 nuclear magnetic resonance (19F-NMR) measurement. The remaining mixture was heated in an oil bath for 48 hours at a temperature of 90 °C or 150 °C with 400 RPM stirring. To prevent overpressure, the glass tube was sealed with a screw-cap. To monitor reactions overtime, a 100 pL aliquot was taken by micropipette at a certain point of reaction time and prepared for19F-NMR measurement.

[0332] At 150 °C, the degradation and fluoride recovery of PVDF occurred rapidly, whereas the reaction proceeded at a noticeably slower rate at 90 °C. The degradation rate of PVDF is stronglytemperature-dependent, as highertemperatures supplygreaterthermal energy that facilitates bond cleavage— particularly the breaking of C-F and C-C bonds within the PVDF backbone. At 150 °C, the reaction kinetics are significantly enhanced, resulting in accelerated defluorination andfasterfluo ride release. In contrast, at 90 °C, the lowerthermal energy leads to a slower degradation process and reduced fluoride recovery over the same reaction period. At 150 °C, the highest fluoride recovery was obtained with sodium amide (94% within 3 hours). The fluoride recovery (%) were calculated and shown in Table 19 for 150 °C and Table 20 for 90°C.

[0333] Table 19

[0334] Table 20

[0335] FIGS. 123 and 124 show the linear calibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of PVDF with two different nucleophiles (CH3SNa, and NH2Na) after 3 h of reaction at 150 °C in HPLC -grade DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the 2 nucleophiles. The total fluorine available from the initial PVDF concentration was 338 mM, 307.2 mM for the reaction solution with CH3SNa, and NH2Na, respectively.

[0336] FIGS. 125 and 126 show the linear calibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of PVDF with two different nucleophiles after 6 h of reaction at 90 °C in HPLC -grade DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the 2 nucleophiles. The total fluorine available from the initial PVDF concentration was 343.2 mM, 325.2 mM for the reaction solution with CH3SNa, and NH2Na, respectively.

[0337] The defluorination and degradation PVDF were carried out in an anhydrous DMSO solution with 99% NH2Na . In a glass pressure tube, 99% sodium amide (243 mg, 6.2 mmol) was dissolved in 3 mLof 99.9% anhydrous DMSO with a heat gun. The above reaction mixture was cooled down at room temperature before polyvinylidene fluoride (PVDF) was added (50 mg, 0.78 mmol). The mixture was then sonicated for 60 seconds. The rest of the mixture in the glass tube was heated in an oil bath at 90 or 150 °C with 400 RPM stirring. To prevent overpressure, the glass tube were sealed with a screw-cap. To check the fluoride recovery over time, the aliquot was taken by micropipette at certain point of reaction time, and prepared for NMR measurement in deuterium oxide. All the collected samples were subjected to19F NMR analysis using 400 MHz NMR instrumentation .

[0338] FIG. 127 shows the linearcalibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of PVDF with 99% NaNH2after 3 h of reaction at 150 °C in anhydrous DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial PVDF concentration was 280.8 mM for the reaction solution with 99% NH2Na.

[0339] FIG. 128 shows the linearcalibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of PVDF with 99% NaNH2after 6 h of reaction at 90 °C in anhydrous DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial PVDF concentration was 289.8 mM for the reaction solution with 99% NH2Na.

[0340] FIG. 129 shows the fluoride recovery efficiency (%) obtained forthe reaction of PVDF with 99% NaNH2in anhydrous DMSO at varying reaction times, the data is also shown in Table 21.

[0341] Table 21

[0342] Example 9: Defluorination and Degradation of Polychlorotrifluoroethylene (PCTFE)

[0343]

[0344] The nucleophiles sodium methane thiolate and sodium amide were reacted in the presence of polychlorotrifluoroethylene (PCTFE) as shown in Scheme 9. In a glass pressure tube, PCTFE (50 mg, 0.43 mmol) was dissolved at 150 °C in HPLC -grade DMSO for overnightand then 95% sodium methanethiolate (0.238 g, 3.4 mmol) or 95% sodium amide (137 mg, 3.4 mmol) was dissolved in 3 mL of HPLC DMSO with a heat gun. The above reaction mixture was cooled down at room temperature before PCTFE was added. The rest of mixture in the glass tube was heated in an oil bath at 90 or 150 °C with 400 RPM stirring. To prevent overpressure, the glass tube were sealed with a screw-cap. To check the fluoride recovery over time, the aliquot was taken by micropipette at certain point of reaction time, and prepared for NMR measurement in deuterium oxide. All the collected samples were subjected to19F NMR analysis using 400 MHz NMR.

[0345] At 150 °C, the reaction exhibited a significant increase in fluoride recovery over time, whereas only partial fluoride recovery was observed at 110 °C. The limited recovery at the lower temperature can be attributed to the poor solubility of the PCTFE polymer in DMSO, resultingfrom its high crystallinity, strongC-F and C-CI bonds, and overall chemical inertness. At 110 °C, the partial fluoride recoveries were 48.1% for CH3SNa and 69.2% for NH2Na. In contrast, at 150 °C, excellent fluoride recoveries were achieved 98.8% for CH3SNa and 97.1% for NH2Na.

[0346] FIGS. 130 and 131 show the linear calibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of PCTFE with two different nucleophiles after 144 h of reaction at 110 °C in HPLC -grade DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6xtimes from the reaction solution ofthe two nucleophiles. The total fluorine available from the initial PCTFE concentration was 205.8 mM for the reaction solution with 95% CH3SNa, and 95% NH2Na, respectively.

[0347] FIG. 132 and 133 show the linear calibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of PCTFE with two different nucleophiles after 48 h of reaction at 150 °C in HPLC -grade DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6xtimes from the reaction solution ofthe two nucleophiles. The total fluorine available from the initial PCTFE concentration was 205.8 mM for the reaction solution with 95% CH3SNa, and 95% NH2Na, respectively.

[0348] FIG. 134 shows the fluoride recovery efficiency (%) obtained forthe reaction of PCTFE with two different nucleophiles (95% CH3SNa, and 95% NH2Na) at varying reaction times at 110 °C in HPLC -grade DMSO. The data is further seen in Table 22.

[0349] Table 22

[0350] The defluorination and degradation PCTFE were carried out in an anhydrous DMSO solution with 99% NH2Na. In a glass pressure tube PCTFE (50 mg, 0.43 mmol) was dissolved at 150 °C for overnight and 99% sodium amide (137 mg, 3.4 mmol) was dissolved in 3 mL of 99.9% anhydrous DMSO with a heat gun. The above reaction mixture was cooled down at room temperature before PCTFE was added. The rest of mixture in the glass tube was heated in an oil bath at 90 or 150 °C with 400 RPM stirring. To prevent overpressure, th e glass tube was sealed with a screw-cap. To check the fluoride recovery overtime, the aliquot wastaken by micropipette at certain point of reaction time, and prepared for NMR measurement in deuterium oxide. All the collected samples were subjected to19F NMR analysis using 400 MHz NMR instrumentation.

[0351] FIG. 135 shows the linearcalibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of PCTFE with 99% NaNH2after 96 h of reaction at 150 °C in anhydrous DMSO. The concentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial PCTFE concentration was 206.4mM for the reaction solution with 99% NH2Na.

[0352] FIG. 136 shows the fluoride recovery efficiency (%) obtained forthe reaction of PCTFE with 99% NaNH2nucleophiles at varying reaction times, the data of which is also shown in Table 23.

[0353] Table 23

[0354] Example 10: Defluorination and Degradation of Perfluoropropionic acid (PFPrA)

[0355] Scheme 10

[0357] The nucleophile sodium amide was reacted in the presence of perfluoropropionicacid (PFPrA) in a molar ratio of 30:1, nucleophile to PFPrA as shown in Scheme 10. In a glass pressure tube, 99% sodium amide (170 mg, 4.3 mmol) was dissolved in 4 mL of 99.9% anhydrous DMSO with a heat gun. The above reaction mixture was cooled down at room temperature before PFPrA was added (15 pL, 0.144 mmol). The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deuterated DMSO solvent and used as the t = 0 aliquot for NMR measurement. The rest of the mixture in the glass tube was heated in an oil bath for 24 hours at 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube were sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain po int of reaction time, and prepared for NMR measurement. All the collected samples were subjected to19F NMR analysis using 400 MHz NMR.

[0358] FIG. 137 shows the reaction progress of perfluoropropionic acid (PFPrA) with 99% sodium amide at 110 °C in anhydrous DMSO as described above. The samples tested 200 pL aliquot taken at varioustimesfrom 0 to 24 h and tested using19F-NMR in anhydrous DMSO- d6with a 400 MHz instrument.

[0359] FIG. 138 shows the linearcalibration curves created by standard addition method used to determine the concentration of F" ion in the reaction solution of PFPrA with 99% NaNH2after 24 h of reaction at 110 °C in anhydrous DMSO. The c.oncentration values marked in these figures represent the fluoride concentrations in the NMR solution, which are diluted 6x times from the reaction solution of the nucleophiles. The total fluorine available from the initial PFBA concentration was 180 mM for the reaction solution with 99% NH2Na.

[0360] Example 11: Defluorination and Degradation of perfluoro-l-heptene (PFPrA)

[0361] Scheme 11

[0362] The nucleophile sodium amide and sodium methane thiolate was reacted in the presence of perfluoro-l-heptene in a molar ratio of 30:1, nucleophile to perfluoro-l-heptene as shown in Scheme 11. In a glass pressure tube, 99% sodium amide (86 mg, 2.2mmol) or 95% CH3SNa (138 mg, 2 mmol) was dissolved in 3 mL of 99.9% anhydrous DMSO with a heat gun. The above reaction mixture was cooled down at room temperature before perfluoro-l- heptene was added (16 pL, 0.074 mmol and 14 pL, 0.0654 mmol respectively). The mixture was then sonicated for 60 seconds. A 200 pL aliquot was taken from the mixture and diluted into 400 pL of deuterated CDCI3solvent and used asthe t = 0 aliquot for NMR measurement. The rest of mixture in the glass tube was heated in an oil bath for 5 hours at 110 °C with 400 RPM stirring. To prevent overpressure, the glass tube were sealed with a screw-cap. To monitor reactions over time, a 200 pL aliquot was taken by micropipette at certain point of reaction time, and prepared for NMR measurement. All the col lected samples were subjected to19F NMR analysis using 400 MHz NMR.

[0363] FIGS. 139 and 140 show the reaction progress of perfluoro-l-heptene with sodium amide and soidium methane thiolate, respectively, at 110 °C in anhyrdous DMSO as described above. The samples tested 200 pLaliquot taken at various times from Oto 24 hours and tested using19F-NMR in DMSO-d6:CDCI3(2:4) with a 400 MHz instrument. Degradation of perfluoro- l-heptene by the two nucleophiles (amide and methane thiolate) is very efficient; the reactions run fast even at room temperature, with all the compounds degraded instantly (faster than the sample preparation time), although the complete recovery of fluoride ions takes a little longer time (up to 5 hours for amide, up to 7 hours for methane thiolate),indicating that some fluorine-containing byproducts are formed duringthe degradation and complete defluorination of these byproducts takes longer.

[0364] FIGS. 141 and 142 show the linear calibration curves obtained using the standard addition method fordeterminingthefluoride ion (F“) concentration in the reaction solutions of perfluoro-l-heptene with 95% CH3SNa and 99% NaNH2after 24 h and 5 h of reaction at 110 °C in anhydrous DMSO, respectively. The concentration values shown in the figures represent the fluoride concentrations measured in the NMR solutions, which were diluted sixfold from the corresponding reaction solutions. The total fluorine available from the initial perfluoro-l-heptene concentration was 305 mM and 349 mM for the reaction systems containing 95% CH3SNa and 99% NaNH2, respectively.

[0365] FIGS. 143 and 144 showthe fluoride recovery efficiency (%) obtained forthe reaction of perfluoro-l-heptene with 95% CH3SNa and 99% NaNH2in anhydrous DMSO at varying reaction times. The data is further shown in Table 24.

[0366] Table 24

[0367] The method disclosed herein is further summarized in the following paragraphs a nd is further characterized by combinations of any and all various aspects described herein.

[0368] According to one aspect of the present disclosure, a method of defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS) includes contacting a sample containing PFAS with a strong nucleophile, wherein the strong nucleophile is selected from a group consisting of thiolate anion, wherein the thiolate anion comprises RiS", wherein Ri ishydrogen, alkyl, alkoxy or another group that is not electron withdrawing, alkoxide anion, wherein the alkoxide anion comprises R2O’, wherein R2is hydrogen, alkyl, alkoxy or another group that is not electron withdrawing, amide ion, wherein the amide ion comprises NH2‘, hydrazine, azide, primary a mine, wherein the primary a mine comprises R3-NH2, wherein R3is hydrogen, alkyl, alkoxy, or another group that is not electron withdrawing, enolate anion, wherein the enolate anion comprises R4RsC=O’, wherein R4 and R5 can independently be alkyl, alkyoxy, or anothergroup that is not electron withdrawing, carbon anion, wherein the carbon anion comprise ReRzRs-C, wherein R6, R7, and R8 is hydrogen, alkyl, alkoxy, oranother group that is not electron withdrawing, acetylide ion, wherein the acetylide ion comprises R9C C’, wherein R9is hydrogen, alkyl, alkoxy, or another group that is not electron withdrawing, and iodide ion, and heatingthe sample to a temperature for 24 hours, wherein the temperature is less than 200°C.

[0369] According to another aspect of the present disclosure, the thiolate anion, the alkoxide anion, the amide ion, the azide, the enolate anion, the carbon anion, the acetylide ion, and the iodide ion are in the form of a salt, wherein a counter cation is Na+, K+, Ba2+, or NH4+.

[0370] According to yet another aspect of the present disclosure, wherein the strong nucleophile is sodium methanethiolate (CH3SNa), sodium ethane thiolate (C2H5SNa), sodium methoxide (CH3ONa), or sodium amide (NH2Na).

[0371] Accordingto anotheraspect ofthe present disclosure, R3is not large enough to cause steric hindrance reducing nucleophilicity.

[0372] Accordingto yet anotheraspect ofthe present disclosure, the strong nucleophile is in molar excess.

[0373] According to another aspect of the present disclosure, the temperature is 110 °C.

[0374] According to yet anotheraspect of the present disclosure, a recovery of fluoride ions from said defluorination and degradation is up to 100% recovery.

[0375] According to another aspect of the present disclosure, byproducts are fluoride ions, formic acid, trifluoroacetic acid, and lH-perfluoroheptane.

[0376] According to yet another aspect of the present disclosure, said PFAS is perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), an ammonium salt of hexafluoropropylene oxide dimer acid (GenX™), perfluorononanoic acid (PFNA), perfluorobutanoic acid (PFBA), perfluorohexanesulphonic acid (PFHxS), or perfluorobutanesulfonic acid (PFBS).

[0377] According to another aspect of the present disclosure, a method of treating orga nofluorine compounds in mild conditions includes dissolving a first amount of strong nucleophile in a liquid solution, adding a second amount of an organofluorine containing sample to the liquid solution, heatingthe solution, and reacting the solution from the adding of the second amount of an organofluorine up to 48 hours.

[0378] According to yet another aspect of the present disclosure, the strong nucleophile is selected from a group consistingof thiolate anion, wherein the thiolate anion comprises RiS", wherein Ri is hydrogen, alkyl, alkoxy or another group that is not electron withdrawing, alkoxide anion, wherein the alkoxide anion comprises R2O", wherein R2is hydrogen, alkyl, alkoxy or another group that is not electron withdrawing, amide ion, wherein the amide ion comprises NH2", hydrazine, azide, primary amine, wherein the primary amine comprises R3- NH2, wherein R3is hydrogen, alkyl, alkoxy, oranothergroup that is not electron withdrawing, enolate anion, wherein the enolate anion comprises R4RsC=O’, wherein R4 and R5 can independently be alkyl, alkyoxy, or another group that is not electron withdrawing, carbon anion, wherein the carbon anion comprise ReRzRs-C", wherein R6, R?, and R8is hydrogen, alkyl, alkoxy, or another group that is not electron withdrawing, acetylide ion, wherein the acetylide ion comprises R9C C, wherein R9is hydrogen, alkyl, alkoxy, or another group that is not electron withdrawing, and iodide ion.

[0379] Accordingto another aspect of the present disclosure, the solution is heated to around100 °C and an operating pressure of the reaction is ambient pressure.

[0380] According to yet anotheraspect of the present disclosure, the solution uses dimethyl sulfoxide (DMSO) as a solvent.

[0381] According to anotheraspect of the present disclosure, the organofluorine containing sample comprises a per- and poly-fluoroalkyl substance or trifluoroacetic acid.

[0382] Accordingto anotheraspect of the present disclosure, the solution uses an anhydrous solvent.

[0383] Accordingto anotheraspect of the present disclosure, the organofluorine is a per-and poly-fluoroalkyl substance (PFAS).

[0384] According to another aspect of the present disclosure, the PFAS is one of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), an ammonium salt of hexafluoropropylene oxide dimer acid (GenX™), perfluorononanoic acid (PFNA),perfluorobutanoic acid (PFBA), perfluorohexanesulphonic acid (PFHxS), or perfluorobutanesulfonic acid (PFBS).

[0385] According to another aspect of the present disclosure, the organofluorine is one of polychlorotrifluoroethylene, polyvinylidene fluoride, trifluoroacetic acid, perfluoro-1- heptene, lH-perfluoroheptane, and perfluoropropionic acid (PFPrA).

[0386] Accordingto anotheraspect ofthe present disclosure, a method of defluorinatingand degrading per- and poly-fluoroalkyl substances (PFAS) through a nucleophilic reaction, the method including dissolving said PFAS in a solution, adding a nucleophile to the solution in molar excess of the PFAS the nucleophile is selected from a group consisting of methane thiolate, ethane thiolate, amide, methoxide, and ethoxide, and heating the solution to at least 85 °C for up to 72 hours.

[0387] According to another aspect of the present disclosure, wherein the nucleophile is added in the form of a salt.

[0388] According to another aspect of the present disclosure, a counter cation to the salt is Na+, K+, Ba2+, or NH4+.

[0389] According to another aspect of the present disclosure, the solution is anhydrous.

[0390] It will be understood by one having ordinary skill in the art that construction of the described disclosure and other components is not limited to any specific material. Other exemplary embodiments of the disclosure disclosed herein may be formed from a wide variety of materials, unless described otherwise herein.

[0391] For purposes of this disclosure, the term "coupled" (in all of its forms, couple, coupling, coupled, etc.) generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nat ure or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and any additional intermediate members being integrally formed as a single unitary body with one another or with the two components. Such joining may be permanent in nature or may be removable or releasable in nature unless otherwise stated.

[0392] It is also important to note that the construction and arrangement ofthe elements of the disclosure, as shown in the exemplary embodiments, is illustrative only. Although only a few embodiments ofthe present innovations have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes andproportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departingfrom the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts, or elements shown as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and / or members or connector or other elements of the system may be varied, the nature or number of adjustment positions provided between the elements may be varied. It should be noted that the elements and / or assemblies of the system may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of the present innovations. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the desired and other exemplary embodiments without departing from the spirit of the present innovations.

[0393] It will be understood thatanydescribed processesorstepswithin described processes may be combined with other disclosed processes or steps to form structures within the scope of the present disclosure. The exemplary structures and processes disclosed herein are for illustrative purposes and are not to be construed as limiting.

Claims

What is claimed is:

1. A method of defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS), the method comprising: contacting a sample containing PFAS with a strong nucleophile, wherein the strong nucleophile is selected from a group consisting of: thiolate anion, wherein the thiolate anion comprises RiS", wherein Ri is hydrogen, alkyl, alkoxy or another group that is not electron withdrawing; alkoxide anion, wherein the alkoxide anion comprises R2O", wherein R2is hydrogen, alkyl, alkoxy or another group that is not electron withdrawing; amide ion, wherein the amide ion comprises NH2"; hydrazine; azide; primary amine, wherein the primary amine comprises R3-NH2, wherein R3is hydrogen, alkyl, alkoxy, or another group that is not electron withdrawing; enolate anion, wherein the enolate anion comprises R4RsC=O’, wherein R4and Rs can independently be alkyl, alkyoxy, or another group that is not electron withdrawing; carbon anion, wherein the carbon anion comprise ReRzRs-C", wherein R6, R7, and R8 is hydrogen, alkyl, alkoxy, or anothergroup that is not electron withdrawing; acetylide ion, wherein the acetylide ion comprises R9C C, wherein R9is hydrogen, alkyl, alkoxy, or another group that is not electron withdrawing; and iodide ion; and: heatingthe sample to a temperature from time of the introduction of the nucleophile up to 48 hours, wherein the temperature is approximately 200°C or less.

2. The method of defluorination and degradation per- and poly-fluoroalkyl substances (PFAS) of claim 1, wherein the thiolate anion, the alkoxide anion, the amide ion, the azide, the enolate anion, the carbon anion, the acetylide ion, a nd the iodide ion are in the form of a salt, wherein a counter cation is Na+, K+, Ba2+, or NH4+.

3. The method of defluorination and degradation per- and poly-fluoroalkyl substances (PFAS) of claim 1, wherein the strong nucleophile is sodium methane thiolate (CH3SNa), sodium ethane thiolate (C2H5SNa), sodium methoxide (CH3ONa), or sodium amide (NH2Na).

4. The method of defluorination and degradation per- and poly-fluoroalkyl substances (PFAS) of claim 1, wherein R3is not large enough to cause steric hindrance reducing nucleophilicity.

5. The method of defluorination and degradation per- and poly-fluoroalkyl substances (PFAS) of claim 1, wherein the strong nucleophile is in molar excess.

6. The method of defluorination and degradation per- and poly-fluoroalkyl substances (PFAS) of claim 1, wherein the temperature is 110 °C.

7. The method of defluorination and degradation per- and poly-fluoroalkyl substances (PFAS) of claim 1, wherein a recovery of fluoride ions from said defluorination and degradation is up to 100% recovery.

8. The method of defluorination and degradation per- and poly-fluoroalkyl substances (PFAS) of claim 1, wherein byproducts are fluoride ions, formic acid, trifluoroacetic acid, and lH-perfluoroheptane.

9. The method of defluorination and degradation per- and poly-fluoroalkyl substances (PFAS) of claim 1, wherein said PFAS is perfluoroocta nesulfonicacid (PFOS), perfluorooctanoic acid (PFOA), an ammonium salt of hexafluoropropylene oxide dimer acid (GenX™), perfluorononanoic acid (PFNA), perfluorobutanoic acid (PFBA), perfluorohexanesulphonic acid (PFHxS), or perfluorobutanesulfonic acid (PFBS).

10. A method of treating organofluorine compounds in mild conditions, the method comprising: dissolving a first amount of strong nucleophile in a liquid solution; adding a second amount of an organofluorine containingsample to the liquid solution;heating the solution; and : reacting the solution from the adding the second amount of an organofluroine up to48 hours.

11. The method of treating orga nofluorine compounds in mild conditions of claim 10, wherein the strong nucleophile is selected from a group consisting of: thiolate anion, wherein the thiolate anion comprises RiS", wherein Ri is hydrogen, alkyl, alkoxy or another group that is not electron withdrawing; alkoxide anion, wherein the alkoxide anion comprises R2O", wherein R2is hydrogen, alkyl, alkoxy or another group that is not electron withdrawing; amide ion, wherein the amide ion comprises NH2"; hydrazine; azide; primary amine, wherein the primary amine comprises R3-NH2, wherein R3is hydrogen, alkyl, alkoxy, or another group that is not electron withdrawing; enolate anion, wherein the enolate anion comprises R4RsC=O’, wherein R4 and R5 can independently be alkyl, alkyoxy, or another group that is not electron withdrawing; carbon anion, wherein the carbon anion comprise ReRzRs-C", wherein R6, R?, and R8is hydrogen, alkyl, alkoxy, or another group that is not electron withdrawing; acetylide ion, wherein the acetylide ion comprises R9C C, wherein R9is hydrogen, alkyl, alkoxy, or another group that is not electron withdrawing; and iodide ion.

12. The method of treating orga nofluorine compounds in mild conditions of claim 11, wherein the solution is heated to around 100 °C and an operating pressure of the reaction is ambient pressure.

13. The method of treating orga nofluorine compounds in mild conditions of claim 11, wherein the solution comprises dimethyl sulfoxide (DMSO) as a solvent.

14. The method of treating orga nofluorine compounds in mild conditions of any one of claims 10-13, wherein the solution uses an anhydrous solvent.

15. The method of treating orga nofluorine compounds in mild conditions of any one of claims 10-14, wherein said orga nofluorine is a per- and poly-fluoroalkyl substance (PFAS).

16. The method of treating organofluorine compounds in mild conditions of claim 15, wherein the PFAS is one of perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), an ammonium salt of hexafluoropropylene oxide dimer acid (GenX™), perfluorononanoic acid (PFNA), perfluorobutanoic acid (PFBA), perfluorohexanesulphonic acid (PFHxS), or perfluorobutanesulfonic acid (PFBS).

17. The method of treating organofluorine compounds in mild conditions of any one of the claims 10-14, wherein said organofluorine is one of polychlorotrifluoroethylene, polyvinylidene fluoride, trifluoroacetic acid, perfluoro-l-heptene, lH-perfluoroheptane, and perfluoropropionic acid (PFPrA).

18. A method ofdefluorinatingand degrading per- and poly-fluoroalkyl substances (PFAS) through a nucleophilic reaction, the method comprising: dissolving said PFAS in a solution; adding a nucleophile to the solution in molar excess of the PFAS, wherein the nucleophile is selected from a group consistingof methane thiolate, ethane thiolate, amide, methoxide, and ethoxide; and heating the solution to at least 85 °C for up to 72 hours.

19. The method of defluorinating and degrading per- and poly-fluoroalkyl substances (PFAS) through a nucleophilic reaction of claim 18, wherein the nucleophile is added in the form of a salt.

20. The method of defluorinating and degrading per- and poly-fluoroalkyl substances (PFAS) through a nucleophilic reaction of claim 19, wherein a countercation to the salt is Na+, K+, Ba2+, or NH4+.

21. The method of defluorinating and degrading per- and poly-fluoroalkyl substances (PFAS) through a nucleophilic reaction of any one of claims 18-20, wherein the solution is anhydrous.

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