Poly anisotropic optical properties

Pettersson, L.Aj., T. Johansson, E Carlsson, H. Arwin, and O. Inganas. 1999. Anisotropic optical properties of doped poly(3,4-ethylenedioxythiophene). Synth Met 101 198. 

Zhokhavets, U., G. Gobsch, H. Hoppe, and N.S. Sariciftci. 2005. A systematic study of the anisotropic optical properties of thin poly(3-octylthiophene)-films in dependence on growth parameters. Thin Solid Films 451 69. 

Side-chain homopolymers based on poly(meth)acrylic derivatives (Fig. 16.14a) have been also widely studied (Andruzzief al., 1999 Rodriguez et al, 2005, 2006). When a suitable flexible spacer mediates between the main chain and the chromophore, these side chain polymers tend to exhibit thermotropic hquid crystalline properties, which favor cooperative chromophores motion during photoorientation and lead to more stable anisotropic optical properties. The azobenzene chromophore strongly influences a material s photoresponse. As a representative example, Ikeda... 

L. A. A. Petterson, F. Carlsson, O. Inganas and H. Arwin, Spectroscopic ellipsometry studies of the optical properties of doped poly(3,4-ethylenedioxythiophene) an anisotropic metal. Thin SolidPilms, 313-314, 356-361 (1998). 

The solution properties of these materials are unusual. They form optically anisotropic solutions in both amide and acid solvent systems over quite wide ranges of concentration and polymer molecular weight. In other words they are among the few known examples of synthetic polymers which can form lyotropic liquid crystals. (That is to say liquid crystals formed by the action of a solvent.) The usual example quoted in this context is poly(y-benzyl-L-glutamate) which forms cholesteric mesomorphic solutions in certain organic solvents. The helical structure adopted by the polypeptide in these solvents behaves as a rigid rod and it is... 

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