Composite photoresponsive polymer

New photoresponsive polymers and peptides have been developed by incorporation of an azobenzene chromophore. The photochemistry of azobenzene-containing polymers has been reviewed,and the ion-conducting polymer composite film of poly(vinyl chloride)/the azobenzene liquid crystal (4)/lithium perchlorate is a promising material for use in photoinduced image storage.Photoisomerization has also been demonstrated... 

The combination of a thermoresponsive polymer and photothermal device allows the development of a photoresponsive polymer composite that is able to release... 

Two kinds of photoresponsive azobenzene polyurethane functionalized multiwalled carbon nanotube (AzoPU-MWNT) composites were synthesized by in-situ polycondensation (50). Core-shell structures with MWNTs as hard core and polymer layer as soft shell were formed and the average thickness of the grafted polymers was about 7-10 nm. The AzoPU-MWNT composites showed reversible photoisomerism behavior. 

T. Kajiyama, H. Kikuchi, and K. Nakamura, Photoresponsive electrooptical effect of liquid crystalline polymer/low molecular weight liquid crystal composite system, Proc. SPIE 1911, 111-121 (1993). 

In pure HFP, the CD spectra are consistent with those of random coil polypeptide chains, and the photoisomerization reaction does not affect the polymer conformation at all. Addition of triethylamine to the HFP solution induces the coil- helix transition, but the amount of base necessary to induce the transition is different for the dark-adapted sample (15% v/v) than for the irradiated one (30% v/v). Thus, at any composition in the range 3-15% v/v of NEtj, exposure to sunlight produces reversible variations of the helix content. Combination of the effects due to the photochromic behavior with appropriate amounts of NEtj allows modulation of the extent of the photoresponse. 

Kajiyama, T., Kikudii, H., and Nakamura, K., Photoresponsive electro-optic effect of (liquid crystal polymer)/(low molecular weight liquid crystal) composite system, Proc. SPIE, 1911, 111, 1993. 

Rather unusually, induced circular dichroism in copolymers of N-vinylcarbazole with different optically active monomers is optimized at particular copolymer compositions and hence offers an obvious route to the design of optically active polymer reagents from N-vinylcarbazole. Analogously, the dependence of excimer emission properties in carbazole-containing polymers on the primary structure of the monomeric units and the microstructure of the polymer backbone offers the possibility to design polymeric systems with predictable photoresponses and energy transfer characteristics. 

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