and become the predominant species with more surface dehydration (Figure ). In contrast to previous work , our data shows no evidence for direct inner-sphere coordination (i.e., ligand-exchange mechanism) between the O-containing functional groups of the PS chains and the Fe(III) atom present at the surface of goethite (i.e., no shift in IR peak positions). Our results indicate PS adsorption is more likely driven by electrostatic and hydrogen bond interactions with ≡FeOH and ≡FeOH2 + sites at the goethite surface.