Photo-sensible (thymine containing) azo-polysiloxanes: synthesis and light induced effects

Abstract

Abstract. The paper presents the possibility to obtain azo-polysiloxanes modified with thymine and their light induced processing with potential interest in opto-electronics or biomolecules nanomanipulation. The presence of the thymine group in the polymeric structure can confer to material biological properties, in the same time the capacity of tymine to generate H-bonds being useful to the relief geometry stabilization in time. The investigated polymers were obtained in a two step reaction, starting from a polysiloxane containing chlorobenzyl groups in the side chain. The azopolysiloxanes' photochromic behaviour was investigated in solid state, using thin films etalated on the surface of a quartz slide. The effect of surface relief structuration process under the action of UV (355 nm) laser radiation was studied. Laser induced effects on the material surface depends on the incident laser fluence and number of pulses.

Synthesis and photochromic behavior of new polyimides containing azobenzene side groups

“…10). It is interesting that in spite of the fact that the polymeric chain is very rigid and the azobenzene groups are connected in a particular way (no major conformational modification after transecis isomerization process is expected) the surface structuration process is possible as was demonstrated also for tymine containing azopolysiloxanes [34]. The better results (corresponding to Fig.…”