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In recent years, polymers containing main-chain or side-chain azobenzene groups have been attracting a great deal of attention because of their potential application in opto-electronic field, biology, energy storage etc. [1, 2]. The most important properties of azobenzene groups are the photochemical trans-cis isomerisation induced by UV or visible light, having as a result conformational changes induced in the entire polymer chains. One of the consequences of the photo-induced conformational change is the possibility to obtain a surface relief grating (SRG) that presents a potential interest for increasing the efficiency of the photo-luminescent diodes [3] or in the field of organic micro-lasers [4] and biomedical materials.
Here we show the possibility to obtain azo-polysiloxanes modified with nucleobases, and their light induced surface processing with potential interest in opto-electronic (SRG) or for the biomolecules nano-manipulation. The investigated polymers were obtained in a two-step reaction, starting from a polysiloxane containing chlorobenzyl groups in the side-chain [2].
The photo chromic behaviour was investigated in solution or, on the solid state, using thin films deposed on the surface of the quartz slide. As a function of the used nucleobases, the surface of the azo-polysiloxanic film can be structured in deferent ways, probably due to the H-bonds generated at supramolecular level. We have demonstrated that the operational conditions can influence in a critical way the occurrence of the photo-induced fluid state (presence or absence of natural visible light) and the gratins formation.
The research activity was realized in the frame of MATNANTECH Program - CEEX Research Project C107/2006.
1. Brozozowski, L., Sargent, E.H., J. Materials Science:Materials in electronics, 12, 483, 2001. 2. Hasegawa, M., Ikawa, T., Tsuchoimori, M., Watanabe, O., J. Appl. Polym. Sci. 86, 17, 2002. 3. Hubert C., Malcor E., Maurin I., Nunzi J.M., Raimond P., Fiorini C.. Appl. Surf. Sci., 186, 29, 2002. 4. Castex M.C., Olivero C., Fischer A., Mousel S., Michelon J., Adès D., Siove A. Appl. Surf. Sci., 197, 822, 2002.
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