Light-Responsive Shape- and Color-Changing Block Copolymer Particles with Fast Switching Speed.
Jinwoo Kim1, Jinseok Park1, Kyunghyun Jung1
1Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
ACS Nano
|March 7, 2024
Summary
This study introduces light-responsive polymer particles that rapidly change shape and color. Integrating spiropyran photoacid molecules enables fast, reversible transformations for advanced intelligent materials.
Area of Science:
- Materials Science
- Polymer Chemistry
- Nanotechnology
Background:
- Intelligent materials with dynamic shape-changing capabilities are crucial for advanced applications.
- Light-responsive polymer systems offer tunable properties for smart material development.
Purpose of the Study:
- To develop a novel light-responsive block copolymer (BCP) particle system.
- To achieve fast, reversible shape and color transitions in BCP particles using spiropyran photoacid (SPPA).
Main Methods:
- Integration of spiropyran photoacid (SPPA) molecules into polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) BCP particles.
- Induction of SPPA photoisomerization using 420 nm light to alter local pH and domain size.
- Incorporation of functional dyes for multicolor responses.
Main Results:
- SPPA photoisomerization induced by 420 nm light decreased the surrounding pH from 5.5 to 3.3.
- Protonation of the P4VP block led to a significant increase in domain size (14 nm to 39 nm) and particle elongation (aspect ratio from 1.8 to 3.4).
- SPPA also altered BCP particle luminescence, enabling dynamic color changes within 10 minutes with high reversibility.
Conclusions:
- The developed BCP particle system demonstrates fast, reversible light-induced shape and color transitions.
- This technology enables multicolor photopatterning, showcasing potential for light-responsive hydrogel displays.
