We investigated the influence of the polymer macromolecular geometry and chain length in azobenzene containing polymeric liquid crystals (azo-PLC). In particular we studied the photomechanical effects (photoinduced expansion and shrinking) on monodispersed azo-PLCs (polydispersity index 1.08-1.17) prepared from the same monomer and different molecular weights, both in linear and 3-arm star conformation. The characterization has been carried out in thin films by high resolution null ellipsometry for a simultaneous and independent determination of both mechanical and optical properties (e. g., thickness and refractive index). The measurement system has been set up in a pump probe configuration for a real time characterization of the photoinduced dynamics. The effect of coupling introduced by the polymer star configuration is discussed.
Comparative Study of Photomechanical Effects in Linear and Star Azopolymers / P., Camorani; Cristofolini, Luigi; M. P., Fontana; L., Angiolini; Cryst, F. PARIS COMPARATIVE STUDY OF PHOTOMECHANICAL EFFECTS IN LINEAR AND STAR AZOPOLYMERS M. O. L. C. R. Y. S. T. L. I. Q.. - In: MOLECULAR CRYSTALS AND LIQUID CRYSTALS. - ISSN 1542-1406. - 500:(2009), pp. 1-9. [10.1080/15421400802713645]
Comparative Study of Photomechanical Effects in Linear and Star Azopolymers
CRISTOFOLINI, Luigi;
2009-01-01
Abstract
We investigated the influence of the polymer macromolecular geometry and chain length in azobenzene containing polymeric liquid crystals (azo-PLC). In particular we studied the photomechanical effects (photoinduced expansion and shrinking) on monodispersed azo-PLCs (polydispersity index 1.08-1.17) prepared from the same monomer and different molecular weights, both in linear and 3-arm star conformation. The characterization has been carried out in thin films by high resolution null ellipsometry for a simultaneous and independent determination of both mechanical and optical properties (e. g., thickness and refractive index). The measurement system has been set up in a pump probe configuration for a real time characterization of the photoinduced dynamics. The effect of coupling introduced by the polymer star configuration is discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
