Water Structure at the Hydrophobic Nanodroplet Surface Revealed by Vibrational Sum Frequency Scattering Using Isotopic Dilution.
J Phys Chem B
; 126(16): 3186-3192, 2022 04 28.
Article
en En
| MEDLINE
| ID: mdl-35417164
The water structure at the hydrophobic/water interface is key toward understanding hydrophobicity at the molecular level. Herein, we characterize the hydrogen-bonding network of interfacial water next to sub-micron-sized hydrophobic oil droplets dispersed in water using isotopic dilution vibrational sum frequency scattering (SFS) spectroscopy. The relative intensity of different modes, the frequency shift of the uncoupled O-D spectrum, and a low-frequency shoulder (2395 cm-1) reveal that water forms an overall stronger hydrogen-bonding network next to hydrophobic droplets compared to bulk water and the air/water interface. Half of the spectral width of the oil droplet SFS spectrum is determined by inter- and intramolecular coupling of water molecules. Isotopic dilution also confirms the presence of a broad distribution (ca. 2640-2745 cm-1) of non-water-hydrogen-bonded O-D modes that are red-shifted and broadened compared to similar species at the air/water interface. This band corroborates the presence of charge transfer between water and oil.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Vibración
/
Agua
Idioma:
En
Revista:
J Phys Chem B
Asunto de la revista:
QUIMICA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Suiza
Pais de publicación:
Estados Unidos