Enhancing Photochromism of Azophenyl Polyether/SnO2 Nanocomposites for Information Encryption by Organic-Inorganic
Yongchao He1, Yu Huang1, E Xu1
1School of Materials Science and Engineering, Chongqing Jiaotong University, Chongqing 400074, China.
ACS Applied Materials & Interfaces
|July 19, 2025
Summary
This study enhances azobenzene polymers for photochromic applications by using tin dioxide (SnO2) nanoparticles to improve isomerization efficiency and stability. The novel composite material enables rapid, durable pattern writing and erasing for anticounterfeiting uses.
Area of Science:
- Materials Science
- Polymer Chemistry
- Nanotechnology
Background:
- Azobenzene polymers are key photochromic materials (PCMs) but face challenges in solid-state efficiency and stability.
- Hindered isomerization and π-π stacking limit performance in traditional azobenzene PCMs.
Purpose of the Study:
- To design and verify a novel composite material for enhanced photochromic properties.
- To improve isomerization speed and stability in azobenzene-based polymers using additive nanoparticles.
- To explore potential applications in anticounterfeiting and information encryption.
Main Methods:
- Density Functional Theory (DFT) for predictive modeling.
- Experimental verification including time-resolved fluorescence spectra and zeta potential tests.
- Fabrication and characterization of azophenyl polyether/SnO2 composite films.
Main Results:
- Controlled charge transfer between SnO2 nanoparticles and azobenzene moieties was achieved, disrupting π-π stacking.
- Isomerization speed was accelerated (response time ≤ 10 s), and the cis conformation stabilized.
- Composite films showed enhanced color-change behavior and stable pattern writing/erasing functionality.
- High contrast ratio (CR) up to 2.4 under violet light demonstrated potential for anticounterfeiting.
Conclusions:
- The azophenyl polyether/SnO2 composite offers superior photochromic performance compared to pristine materials.
- The charge interaction strategy effectively overcomes limitations of solid-state isomerization in azobenzene polymers.
- The material shows significant promise for advanced anticounterfeiting and data encryption technologies.
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