Light-Sensitive Azobenzene-Containing
Liquid Crystalline Polymers
16
Carlos Sánchez-Somolinos
Contents
Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448
Photochemistry of Azobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450
Macromolecular Architecture of Azobenzene Containing LCPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453
Photoinduced Effects in Azobenzene Containing LCPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456
Photoresponsive Liquid Crystalline Polymers for Optical Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 460
Photoalignment of Microphase Separated Block Copolymer Morphologies . . . . . . . . . . . . . . . . . . 467
Light-Induced Mechanical Actuation in Azobenzene Containing Liquid Crystalline
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
Summary and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475
Abstract
Photoresponsive Liquid Crystalline Polymers bear light sensitive units that
reversibly undergo transformations between their isomer forms when exposed
to light in their absorption bands. These transformations, taking place at the
molecular level, influence the electronic molecular structure and as a result the
optical absorption of the molecule, a phenomenon that is known as photochromism. This light-induced change of the color of the material is of great interest in
the preparation of systems such as optical memories and switches. Besides, the
isomerization of the chromophores can lead to motions at the molecular level that
can be amplified through cooperative effects typical in liquid crystalline materials
resulting in photoinduced effects and properties.
C. Sánchez-Somolinos (*)
Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC-Universidad de Zaragoza, Zaragoza,
Spain
CIBER in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
e-mail: carloss@unizar.es
© Springer Nature Switzerland AG 2020
L. Zhu, C. Y. Li (eds.), Liquid Crystalline Polymers, Polymers and Polymeric
Composites: A Reference Series, https://doi.org/10.1007/978-3-030-43350-5_63
447
Liquid Crystalline Polymers
16
Carlos Sánchez-Somolinos
Contents
Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448
Photochemistry of Azobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450
Macromolecular Architecture of Azobenzene Containing LCPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453
Photoinduced Effects in Azobenzene Containing LCPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456
Photoresponsive Liquid Crystalline Polymers for Optical Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 460
Photoalignment of Microphase Separated Block Copolymer Morphologies . . . . . . . . . . . . . . . . . . 467
Light-Induced Mechanical Actuation in Azobenzene Containing Liquid Crystalline
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
Summary and Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475
Abstract
Photoresponsive Liquid Crystalline Polymers bear light sensitive units that
reversibly undergo transformations between their isomer forms when exposed
to light in their absorption bands. These transformations, taking place at the
molecular level, influence the electronic molecular structure and as a result the
optical absorption of the molecule, a phenomenon that is known as photochromism. This light-induced change of the color of the material is of great interest in
the preparation of systems such as optical memories and switches. Besides, the
isomerization of the chromophores can lead to motions at the molecular level that
can be amplified through cooperative effects typical in liquid crystalline materials
resulting in photoinduced effects and properties.
C. Sánchez-Somolinos (*)
Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC-Universidad de Zaragoza, Zaragoza,
Spain
CIBER in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, Spain
e-mail: carloss@unizar.es
© Springer Nature Switzerland AG 2020
L. Zhu, C. Y. Li (eds.), Liquid Crystalline Polymers, Polymers and Polymeric
Composites: A Reference Series, https://doi.org/10.1007/978-3-030-43350-5_63
447