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Polarization Dependent Photoinduced Supramolecular Chirality in High-Performance Azo Materials
Sekvan Bagatur1, Marcel Schlesag1, Thomas Fuhrmann-Lieker1
1Physical Chemistry of Nanomaterials, Institute of Chemistry and Center for Interdisciplinary Nanostructure Science and Technology, University of Kassel, Heinrich-Plett Str. 40, 34132 Kassel, Germany.
Molecules (Basel, Switzerland)
|June 2, 2021
Summary
This study demonstrates photo-induced supramolecular chirality in polymer thin films. Film thickness influences light polarization rotation, with high stability observed for several days.
Area of Science:
- Polymer Science
- Materials Science
- Optics
Background:
- Achiral amorphous polymers with azo groups can exhibit photo-induced properties.
- Supramolecular chirality is a key phenomenon in advanced materials.
Purpose of the Study:
- To investigate photo-induced supramolecular chirality in polymer thin films.
- To analyze the impact of film thickness on optical properties.
- To assess the temporal stability of induced chirality.
Main Methods:
- Fabrication of thin films from achiral amorphous polymers with azo side-chains.
- Polarimetric measurements to quantify azimuthal rotation and ellipticity.
- Time-resolved measurements to study temporal stability and dynamics.
Main Results:
- Photo-induced supramolecular chirality was successfully demonstrated.
- Azimuthal rotation of polarized light increased with film thickness, reaching 112.5°/μm.
- Induced chirality remained stable for several days.
- Time-resolved ellipticity measurements suggest a two-step process involving isomerization and mass flow.
Conclusions:
- Film thickness is a critical parameter for controlling photo-induced supramolecular chirality.
- The observed chirality exhibits significant temporal stability.
- A two-step mechanism involving trans-cis isomerization and photo-induced mass flow explains the observed dynamics.
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