Molecular orientation of polar self-assembled films

Molecular orientation of polar self-assembled films of carbazole main-chain polymers having a chromophore in a side-chain were investigated by a second-harmonic generation (SHG) phase measurement. In our SHG phase measurement, poly(methyl methacrylate) thin film doped with p-nitroaniline (PNA/PMMA) was used as a standard sample and an oscillator, because the directional sense of PNA was able to be controlled by the polarity of an electric field. The interference pattern between the two poled PNA/PMMA films was shifted by pi depending on the polarity of the films. The interference pattern between the poled PNA/PMMA film and the self-assembled film indicated that the directional sense of the net dipole moment of the self-assembled film was the same as the direction of shear stress.