Qhov sib txawv tseem ceeb ntawm PFOA thiab PFOS yog tias PFOA muaj pawg carboxylic ua haujlwm, qhov PFOS muaj sulfonic ua haujlwm pab pawg.
PFOA thiab PFOS yog cov tshuaj organofluorine. Hauv lwm lo lus, ob yam khoom no muaj cov pa roj carbon atom txuas nrog fluorine atoms. Yog li, cov tshuaj no muaj cov khoom tshwj xeeb.
PFOA yog dab tsi?
Perfluorooctanoic acid lossis PFOA yog hom perfluorinated carboxylic acid uas muaj cov tshuaj formula C8HF15O2. Lub hauv paus conjugate ntawm no compound yog perfluorooctanoate. Cov tshuaj no muaj thoob ntiaj teb siv nyob rau hauv cov txheej txheem tshuaj raws li ib tug surfactant thiab raws li ib tug khoom feedstock thiab. Txawm li cas los xij, vim muaj ntau yam kev txhawj xeeb txog kev noj qab haus huv, muaj qee qhov kev cai siv cov tshuaj no. Cov tshuaj no raug suav hais tias yog carcinogen.
Thaum xav txog cov qauv tshuaj ntawm PFOA, nws muaj perfluorinated n-octyl "tail group" thiab carboxylated "head group." Cov pab pawg taub hau no feem ntau yog hydrophilic, thiab cov pawg neeg Tail yog ob qho tib si hydrophobic thiab lipophobic. Ntxiv mus, tus Tsov tus tw yog inert thiab qhia negligible tshuaj reactivity. Yog li ntawd, cov pab pawg neeg no tsis tuaj yeem muaj kev cuam tshuam zoo nrog cov polar lossis nonpolar tshuaj moieties. Nyob rau hauv sib piv, cov pab pawg neeg lub taub hau yog chemically reactive thiab muaj peev xwm cuam tshuam nrog cov pawg polar xws li dej. Qhov lipophobic xwm ntawm pawg neeg Tail los ntawm nws cov qauv fluorocarbon uas tsis tshua muaj kev cuam tshuam rau London rog dua li hydrocarbons.
PFOA muaj cov tshuaj formula C8HF15O2, thiab cov molar loj yog 414.07 g / mol. Nws zoo nkaus li cov khoom dawb uas yog ib nrab soluble hauv dej thiab soluble hauv polar organic solvents.
Daim duab 01: Cov Qauv Tshuaj ntawm PFOA
Cov kev lag luam loj ntawm PFOA suav nrog cov ntaub pua plag, upholstery, kev lag luam khaub ncaws, kev tsim khoom hauv pem teb, kev lag luam textile, hluav taws kub sib ntaus ua npuas ncauj, thiab kev tsim khoom sealant. Cov tshuaj no tuaj yeem ua tus surfactant hauv emulsion polymerization lossis fluoropolymer. Tsis tas li, nws muaj txiaj ntsig zoo li lub tsev thaiv rau kev tsim cov perfluoroalkyl-substituted compounds, polymers, thiab lwm yam.
PFOS yog dab tsi?
PFOS sawv cev rau perfluorooctanesulfonic acid. Nws lub hauv paus conjugate yog perfluorooctanesulfonate. Cov tshuaj no yog ib qho anthropogenic fluorosurfactant uas suav hais tias yog cov pa phem. Yav dhau los, cov khoom no yog cov khoom tseem ceeb hauv Scotchgard (ib hom ntaub thaiv los ntawm 3M). Tom qab ntawd, nws tau ntxiv rau Stockholm Convention ntawm Thawj Tswj Hwm Organic Pollutants (Tsib Hlis 2009).
Daim duab 02: Cov Qauv Tshuaj ntawm PFOS
Peb tuaj yeem tsim PFOS kev lag luam, lossis nws los ntawm kev ua kom tsis zoo ntawm cov khoom ua ntej. Txog tam sim no, qib ntawm PFOS kuaj pom hauv cov tsiaj qus tuaj yeem ua rau muaj txiaj ntsig zoo rau kev noj qab haus huv, thiab nws tuaj yeem ua rau mob raum mob.
Cov tshuaj formula rau PFOS yog C8HF17O3S, thiab molar mass yog 500 g / mol. Muaj cov subunits ntawm C8F17 hauv PFOS uas yog hydrophobic thiab lipophobic. Cov cuab yeej no zoo ib yam li lwm cov fluorocarbons. Txawm li cas los xij, nws kuj muaj sulfonic acid pawg lossis sulfonates, uas yog polar. Tsis tas li ntawd, PFOS yog ib qho chaw ruaj khov tshwj xeeb hauv kev lag luam thiab hauv ib puag ncig vim muaj kev cuam tshuam los ntawm kev sib xyaw carbon-fluorine bonds. Tsis tas li ntawd, nws yog fluorosurfactant uas tuaj yeem txo qhov nro ntawm cov dej piv rau hydrocarbon surfactants.
Qhov txawv ntawm PFOA thiab PFOS yog dab tsi?
Perfluorooctanoic acid lossis PFOA id ib hom perfluorinated carboxylic acid muaj cov tshuaj formula C8HF15O2 thaum PFOS sawv cev rau perfluorooctanesulfonic acid. Qhov sib txawv tseem ceeb ntawm PFOA thiab PFOS yog tias PFOA muaj pawg carboxylic ua haujlwm, thaum PFOS muaj sulfonic ua haujlwm pab pawg.
Cov infographic hauv qab no teev qhov sib txawv ntawm PFOA thiab PFOS hauv daim ntawv teev npe.
Summary – PFOA vs PFOS
PFOA thiab PFOS yog cov tshuaj organofluorine. PFOA sawv cev rau perfluorooctanoic acid thaum PFOS sawv cev rau perfluorooctanesulfonic acid. Qhov sib txawv tseem ceeb ntawm PFOA thiab PFOS yog tias PFOA muaj pawg carboxylic ua haujlwm, thaum PFOS muaj sulfonic ua haujlwm pab pawg.
