Photoresponsive Block Copolymer Nanostructures through Implementation of Arylazopyrazoles
Katharina Ziegler1, Lisa Schlichter1, Yorick Post1
1Organic Chemistry Institute and Center for Soft Nanoscience, University of Münster, Corrensstraße 40, 48149 Münster, Germany.
ACS Macro Letters
|August 2, 2024
Summary
Responsive block copolymers with photoswitchable arylazopyrazole units reversibly change their self-assembled nanostructures in water. Light triggers transitions between spherical and cylindrical micelles, enabling dynamic functional materials.
Area of Science:
- Polymer Chemistry
- Materials Science
- Nanotechnology
Background:
- Amphiphilic block copolymers self-assemble into diverse nanostructures.
- Molecular photoswitches offer environmental responsiveness.
- Arylazopyrazoles (AAPs) change hydrophobicity upon light irradiation.
Purpose of the Study:
- To synthesize photoswitchable block copolymers with AAP units.
- To investigate the light-induced self-assembly behavior of these polymers.
- To demonstrate reversible control over nanostructure morphology.
Main Methods:
- RAFT polymerization to create POEGMA-b-PAAPMA copolymers.
- Characterization of photochemical properties of AAP units within polymers.
- Self-assembly studies in aqueous solutions under UV and green light irradiation.
Main Results:
- Successful synthesis of photoswitchable block copolymers with retained AAP photochemistry.
- Polymers self-assemble into supramolecular morphologies in water.
- Photoisomerization reversibly switches self-assembly behavior, forming spherical and cylindrical micelles.
Conclusions:
- Photoswitchable block copolymers enable light-controlled reversible changes in nanostructure morphology.
- These materials hold promise for developing dynamic and responsive functional systems.
- The AAP photoswitch is effective within a polymer architecture for tunable self-assembly.
