Optical Behavior and Surface Morphology of the Azobenzene Functionalized Dendrimer in Organic Thin Monolayers

A functionalized dendrimer containing 48 azobenzene was synthesized. Many isolated featureless domains were explicitly observed even at the air/water interface. Also, the monolayers were representatively observed, showing a change of surface pressure with irradiation time and wavelength. In atomic force microscopy(AFM) images, larger domains contained irregularly shaped structures on the top, while smaller ones were free from such defects. In the optical absorption spectra of the monolayer films after UV irradiation and heat treatment, only the photoisomerization of the G4-48 Azo-dendrimer monolayers was observed, revealing a decrease of absorbance peaks without any change of the spectral shape. This suggests that the functional group and the symmetric chain affect optical behavior and morphological change.