Second-Harmonic Generation Microscopy of Glass–Water and Glass–Air Interfaces

Glass–water and glass–air interfaces were visualized by second-harmonic generation microscopy. It was shown that the electrostatic surface potential can be determined from the recorded intensity of the signal from the glass surface in contact with solutions with different pH. Comparison of images of glass in contact with air and an aqueous solution at pH 2 hinted towards the similarity in the molecular structure of these interfaces.