Characteristics of dendrimer functionalized with azobenzene for the application to nano-level photo-switching device

If we can make characterization of nano-structure with functionality, the molecular level device will be obtained. The dendrimer has been well known as a promising macromolecules for a building the organized nanostructure, which of the size can be controlled and which of periphery can be terminated by various functionalities. In this study, we synthesized dendrimers containing light switchable units, azobenzene group. Their chemical structure was verified by using NMR study and UV spectroscopy. To apply to the molecular level switching device or data storage system using Langmuir-Blodgett(LB) film, we firstly investigated the monolayer behavior using π-A isotherm at air/water interface. And then the surface pressure shift of monolayer by light irradiation was also measured. As a result, the monolayer of dendrimer with azobenzene group showed the reversible photo-switching behavior by the isomerization of azobenzene group in their periphery. This result strongly suggests that a dendrimer with azobenzene group can be applied to high efficient photo-switching device of molecular level