The characterization of the crystalline and liquid crystalline properties of organic monolayers at the air-water interface by means of the Maxwell displacement current and optical second harmonic generation technique.

Abstract

Organic monolayers at the air-water interface show the characteristic surface polarization phenomena, such as spontaneous polarization and non-linear polarization, due to their asymmetric structure. Maxwell displacement current (MDC) and second harmonic generation (SHG) measurement can detect these surface polarization phenomena, thus allows us to analyze the structure of monolayers. In the present study, the liquid crystalline properties of the monolayers, such as flow orientation and the flexoelectric effect, are investigated by MDC and SHG. It is concluded that monolayers at the air-water interface have the liquid crystalline property as well as the crystalline property.