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Molecular Fingerprints of Hydrophobicity at Aqueous Interfaces from Theory and Vibrational Spectroscopies

[Image: see text] Hydrophobicity/hydrophilicity of aqueous interfaces at the molecular level results from a subtle balance in the water–water and water–surface interactions. This is characterized here via density functional theory–molecular dynamics (DFT-MD) coupled with vibrational sum frequency ge...

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Detalles Bibliográficos
Autores principales: Pezzotti, Simone, Serva, Alessandra, Sebastiani, Federico, Brigiano, Flavio Siro, Galimberti, Daria Ruth, Potier, Louis, Alfarano, Serena, Schwaab, Gerhard, Havenith, Martina, Gaigeot, Marie-Pierre
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2021
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9004482/
https://www.ncbi.nlm.nih.gov/pubmed/33852317
http://dx.doi.org/10.1021/acs.jpclett.1c00257
Descripción
Sumario:[Image: see text] Hydrophobicity/hydrophilicity of aqueous interfaces at the molecular level results from a subtle balance in the water–water and water–surface interactions. This is characterized here via density functional theory–molecular dynamics (DFT-MD) coupled with vibrational sum frequency generation (SFG) and THz-IR absorption spectroscopies. We show that water at the interface with a series of weakly interacting materials is organized into a two-dimensional hydrogen-bonded network (2D-HB-network), which is also found above some macroscopically hydrophilic silica and alumina surfaces. These results are rationalized through a descriptor that measures the number of “vertical” and “horizontal” hydrogen bonds formed by interfacial water, quantifying the competition between water–surface and water–water interactions. The 2D-HB-network is directly revealed by THz-IR absorption spectroscopy, while the competition of water–water and water–surface interactions is quantified from SFG markers. The combination of SFG and THz-IR spectroscopies is thus found to be a compelling tool to characterize the finest details of molecular hydrophobicity at aqueous interfaces.