This project examined how perfluorinated surfactants self-assemble in aqueous environments and how they interact with natural materials at solid–liquid interfaces. Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants, and understanding how their aggregation and interfacial behaviour depend on counterions and surrounding conditions is essential for assessing their transport, bioavailability, and potential remediation strategies.
Small-angle X-ray scattering, small-angle neutron scattering, and neutron reflection were used to resolve both bulk and interfacial structures. The first part of the work focused on the micellar structure of perfluorooctanoate salts with different counterions, revealing pronounced differences in micelle shape, hydration, temperature response, and isotope effects between monovalent and divalent systems. The second part investigated the adsorption of fluorocarbon surfactants onto a seed protein layer at a silica interface, showing the formation of mixed protein–surfactant layers and selective desorption behaviour upon rinsing.
Together, the results provided molecular-level insight into how PFAS aggregate and interact with environmentally relevant biomolecules at interfaces. The work established neutron and X-ray scattering as powerful complementary tools for probing PFAS behaviour and contributed knowledge relevant to understanding environmental transport, health impacts, and remediation of fluorinated surfactants.