Determining the Surface pKa of Perfluorooctanoic Acid

Lila J. Musegades; Owen P. Curtin; Jenée D. Cyran

doi:10.1021/acs.jpcc.3c07235

Determining the Surface pK_a of Perfluorooctanoic Acid

Lila J. Musegades, Owen P. Curtin, Jenée D. Cyran

Chemistry Department

Research output: Contribution to journal › Article › peer-review

6 Scopus citations

Abstract

Perfluorooctanoic acid (PFOA) is an environmentally prevalent and persistent organic pollutant with toxic and bioaccumulative properties. Despite the known importance of perfluorinated pollutants in the global environment, molecular-level details of the physicochemical behavior of PFOA on aqueous interfaces remain poorly understood. Here, we utilized two surface-specific techniques, vibrational sum frequency generation spectroscopy (SFG) and surface tensiometry, to investigate the pH-induced structural changes of PFOA and octanoic acid (OA) and determined the apparent pK_a at the air–water surface. The SFG spectra and surface activity model were investigated over a wide range of pHs. With the surface tension measurements, the surface pK_a values for OA and PFOA are determined to be 3.8 ± 0.1 and 2.2 ± 0.2, respectively. These results could provide insights into improved remediation of PFOAs and may impact climate modeling of perfluorinated alkyl chain molecules.

Original language	American English
Pages (from-to)	1946-1951
Number of pages	6
Journal	Journal of Physical Chemistry C
Volume	128
Issue number	5
DOIs	https://doi.org/10.1021/acs.jpcc.3c07235
State	Published - 8 Feb 2024

Keywords

molecules
nonlinear optics
pH
polarization
surface tension

EGS Disciplines

Chemistry

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1021/acs.jpcc.3c07235

Determining the Surface p em K em sub a sub of PerfluorooctanFinal published version, 1.27 MBLicense: CC BY-NC-ND

Cite this

@article{861de5eb76e541e7930612390ceab1f9,

title = "Determining the Surface pKa of Perfluorooctanoic Acid",

abstract = "Perfluorooctanoic acid (PFOA) is an environmentally prevalent and persistent organic pollutant with toxic and bioaccumulative properties. Despite the known importance of perfluorinated pollutants in the global environment, molecular-level details of the physicochemical behavior of PFOA on aqueous interfaces remain poorly understood. Here, we utilized two surface-specific techniques, vibrational sum frequency generation spectroscopy (SFG) and surface tensiometry, to investigate the pH-induced structural changes of PFOA and octanoic acid (OA) and determined the apparent pKa at the air–water surface. The SFG spectra and surface activity model were investigated over a wide range of pHs. With the surface tension measurements, the surface pKa values for OA and PFOA are determined to be 3.8 ± 0.1 and 2.2 ± 0.2, respectively. These results could provide insights into improved remediation of PFOAs and may impact climate modeling of perfluorinated alkyl chain molecules.",

keywords = "molecules, nonlinear optics, pH, polarization, surface tension",

author = "Musegades, {Lila J.} and Curtin, {Owen P.} and Cyran, {Jen{\'e}e D.}",

note = "Publisher Copyright: {\textcopyright} 2024 American Chemical Society",

year = "2024",

month = feb,

day = "8",

doi = "10.1021/acs.jpcc.3c07235",

language = "American English",

volume = "128",

pages = "1946--1951",

number = "5",

}

TY - JOUR

T1 - Determining the Surface pKa of Perfluorooctanoic Acid

AU - Musegades, Lila J.

AU - Curtin, Owen P.

AU - Cyran, Jenée D.

PY - 2024/2/8

Y1 - 2024/2/8

N2 - Perfluorooctanoic acid (PFOA) is an environmentally prevalent and persistent organic pollutant with toxic and bioaccumulative properties. Despite the known importance of perfluorinated pollutants in the global environment, molecular-level details of the physicochemical behavior of PFOA on aqueous interfaces remain poorly understood. Here, we utilized two surface-specific techniques, vibrational sum frequency generation spectroscopy (SFG) and surface tensiometry, to investigate the pH-induced structural changes of PFOA and octanoic acid (OA) and determined the apparent pKa at the air–water surface. The SFG spectra and surface activity model were investigated over a wide range of pHs. With the surface tension measurements, the surface pKa values for OA and PFOA are determined to be 3.8 ± 0.1 and 2.2 ± 0.2, respectively. These results could provide insights into improved remediation of PFOAs and may impact climate modeling of perfluorinated alkyl chain molecules.

AB - Perfluorooctanoic acid (PFOA) is an environmentally prevalent and persistent organic pollutant with toxic and bioaccumulative properties. Despite the known importance of perfluorinated pollutants in the global environment, molecular-level details of the physicochemical behavior of PFOA on aqueous interfaces remain poorly understood. Here, we utilized two surface-specific techniques, vibrational sum frequency generation spectroscopy (SFG) and surface tensiometry, to investigate the pH-induced structural changes of PFOA and octanoic acid (OA) and determined the apparent pKa at the air–water surface. The SFG spectra and surface activity model were investigated over a wide range of pHs. With the surface tension measurements, the surface pKa values for OA and PFOA are determined to be 3.8 ± 0.1 and 2.2 ± 0.2, respectively. These results could provide insights into improved remediation of PFOAs and may impact climate modeling of perfluorinated alkyl chain molecules.

KW - molecules

KW - nonlinear optics

KW - pH

KW - polarization

KW - surface tension

UR - http://www.scopus.com/inward/record.url?scp=85184325397&partnerID=8YFLogxK

UR - https://scholarworks.boisestate.edu/chem_facpubs/174

U2 - 10.1021/acs.jpcc.3c07235

DO - 10.1021/acs.jpcc.3c07235

M3 - Article

SN - 1932-7447

VL - 128

SP - 1946

EP - 1951

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

IS - 5

ER -