Interfacial Activity and Surface pK_a of Perfluoroalkyl Carboxylic Acids (PFCAs).

ABSTRACT: Perfluoroalkyl carboxylic acids (PFCAs) are widely used synthetic chemicals that are known for their exceptional stability and interfacial activity. Despite their industrial and environmental significance, discrepancies exist in the reported pK_a values for PFCAs, often spanning three to four units. These disparities stem from an incomplete understanding of how pH influences the ionized state of PFCA molecules in the bulk solution and at the air-water interface. Using pH titration and surface tension measurements, we show that the pK_a values of the PFCAs adsorbed at the air-water interface differ from the bulk. Below the equivalence point, the undissociated and dissociated forms of the PFCAs exist in equilibrium, driving to the spontaneous adsorption and

SUBMITTER: Patel R 

PROVIDER: S-EPMC10883055 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature