Vibrational spectroscopy is frequently used to characterize liquids in nanoconfined environments or at solid-liquid interfaces and probe the effect of the confining framework or solid surface on the liquid structure and dynamics relative to the corresponding bulk fluid. However, it is still unclear what molecular-level information can be obtained from such measurements. We address this question by using molecular dynamics simulations to reproduce the linear and nonlinear vibrational spectra of water at hydrophilic (hydroxyl-terminated) silica interfaces. To simplify the spectra, the OH stretching region of isotopically dilute HOD in D<sub>2</sub>O is considered. The results provide guidance on the strengths and limitations of vibrational spectroscopy by elucidating what features of the strongly modified structure and dynamics of interfacial liquids are (and are not) manifested in various spectra.

Simulations of the vibrational spectroscopy of water at silica interfaces

253rd National Meeting (2017)

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