Water orientation at hydrophobic interfaces
J. Chem. Phys. , Volume 143 - Issue Article number: 084708 p. 1- 6
We study the structure and orientation of water molecules at water/alkane and water/polydimethylsiloxane interfaces with surface specific intensity and heterodyne-detected vibrational sum-frequency generation (HD-VSFG) spectroscopy. We observe that the hydrogen-bond structure of the water molecules is enhanced at these interfaces compared to the water/air interface. We also find that the water molecules at the interface show a net orientation of their O–H groups pointing towards to the hydrophobic layer.