Interfacial properties of poly- and perfluoroalkyl substances at the air-water interface

Poly- and perfluoroalkyl substances (PFAS) are a group of manmade chemicals with each or more than one hydrogen atom on the alkyl chain replaced by a fluorine atom. PFAS have been recognized as contaminants of emerging concern (CECs) duo to toxicity, bioaccumulation, and environmental persistence. Therefore, PFAS properties and remediation methods are being widely investigated in recent studies. Study of interfacial properties of PFAS is of great importance as the air-water interface is a retention source for PFAS transport in atmosphere, soil, and groundwater. In the present study, PFAS adsorption kinetics and equilibrium at the air-water interface are studied by measuring the dynamic surface tension. PFAS interfacial rheological properties are also determined by oscillatory shear flow. We evaluate the effect of perfluoroalkyl chain length, concentration, and composition on the adsorption and viscoelastic behavior of PFAS at the interface.