Azobenzene functionalized polymers

Kumar, J., Li, L., Jiang, X. L., Kim, D.-Y., Lee, T. S., Tripathy, S. (1998). Gradient force the mechanism for surface relief grating formation in azobenzene functionalized polymers. Appl. Phys. Lett. 72, 2096-209S. 

Lagugne Labarthet F, Buffeteau T, Sourisseau C. 2002. Optical erasures and unusual surface reliefs of holographic gratings inscribed on thin films of an azobenzene functionalized polymer. Phys Chem Chem Phys 4(16) 4020 4029. 

Hasegawa M, Keum C D, Watanabe O. 2002b. Enhanced photofabrication of a surface nanostructure on azobenzene functionalized polymer films with evaporated gold nano islands. Adv Mater 14 1738 1741. 

Minoura N, et al. 2004. Preparation of azobenzene containing polymer membranes that function in photoregulated molecular recognition. Macromolecules 37(25) 9571 9576. 

Yaroschuk O, et al. 2001. Light induced structures in liquid crystalline side chain polymers with azobenzene functional groups. J Chem Phys 114(12) 5330 5337. 

Ionic complexes of polyelectrolytes and charged azobenzenes have optical response of the azobenzene, although influenced by the polymer matrix, as discussed earlier. The repeated E-Z isomerization is considered as a primer condition for the light-induced mass transport. Peculiar to the latter is the fact that the process is not more a local light-induced event but implies a translational motion of chromophores (Fig. 2.1). Moreover, the mass is transported only if the chromophores involve the passive polymer chains in their translation. This explains the high efficiency of SRG formation in functionalized polymers (Natansohn and Rochon, 2002 Viswanathan et al., 1999), why the covalent bonding has been considered as a necessary condition for the effective light-induced mass transport (Oliveira et al., 2005 Zucolotto et al., 2003 Fiorini et al., 2000 Viswanathan et al., 1999 ), and why the extremely effective SRG formation in the materials with ionic-bounded azobenzene (Kulikovska et al., 2007 Stumpe... 

Figure 7.2. Photoswitch of the solubility of chains, (a) Schematic drawing of the phototriggered coiiapse and aggregation of azobenzene-containing polymers in poor soivent conditions or ciose to iow critical solubility temperature (LCST). (b) Typical variation of the radius of the chains as a function of solvent parameter, or temperature in the case of chains having a LCST in water. Bold line parent chain with no azobenzene dashed and dot-dashed lines azo-modified chains, respectively, exposed to UV and dark-adapted.

Seki T. 2004. Dynamic photoresponsive functions in organized layer systems comprised of azobenzene containing polymers. Polym J 36 435 454. 

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