Vibrational exciton delocalization precludes the use of infrared intensities as proxies for surfactant accumulation on aqueous surfaces.

ABSTRACT: Surface-sensitive vibrational spectroscopy is a common tool for measuring molecular organization and intermolecular interactions at interfaces. Peak intensity ratios are typically used to extract molecular information from one-dimensional spectra but vibrational coupling between surfactant molecules can manifest as signal depletion in one-dimensional spectra. Through a combination of experiment and theory, we demonstrate the emergence of vibrational exciton delocalization in infrared reflection-absorption spectra of soluble and insoluble surfactants at the air/water interface. Vibrational coupling causes a significant decrease in peak intensities corresponding to C-F vibrational modes of perfluorooctanoic acid molecules. Vibrational excitons also form between arachidic acid surfactants wit

SUBMITTER: Carter-Fenk KA 

PROVIDER: S-EPMC8221057 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature