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 Azo-Polymers / L. Angiolini; L. Giorgini; F. Paris; P. Camorani; L. Cristofolini; M. P. Fontana. - In: MOLECULAR CRYSTALS AND LIQUID CRYSTALS. - ISSN 1542-1406. - STAMPA. - 500:(2009), pp. 1-9. [10.1080/15421400802713645]
Comparative Study of Photomechanical Effects in Linear and Star Azo-Polymers
ANGIOLINI, LUIGI;GIORGINI, LORIS;PARIS, FABIO;
2009
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.
