Reversible On-Off Luminescence Switching in Self-Healable Hydrogels

Area of Science:

• Materials Science
• Polymer Chemistry
• Supramolecular Chemistry

Background:

• Responsive hydrogels offer tunable properties for advanced applications.
• Lanthanide complexes are known for their unique luminescent characteristics.
• Integrating responsive elements with luminescent materials is an active research area.

Purpose of the Study:

• To develop novel hybrid hydrogels with simultaneous self-healing and luminescence switching capabilities.
• To investigate the mechanism behind the reversible "on-off" luminescence switching.
• To explore the processing of these hybrid hydrogels into various shapes.

Main Methods:

• Doping lanthanide complexes into poly(2-acrylamido-2-methyl-1-propanesulfonicacid) (PAMPSA) polymer hydrogel.
• Fabrication of hybrid hydrogels into desired shapes.
• Testing self-healing properties without external stimuli.
• Investigating "on-off" luminescence switching triggered by acid-base vapor exposure.

Main Results:

• The hybrid hydrogels exhibit simultaneous self-healing and reversible "on-off" luminescence switching.
• Luminescence switching is triggered by acid-base vapor, specifically ammonia or triethylamine.
• The mechanism involves protonation of organic ligands competing with lanthanide coordination, affecting luminescence yield.
• Self-healing occurs without any external stimulus.

Conclusions:

• A facile method for preparing novel responsive hybrid hydrogels with dual functionalities has been established.
• The developed hydrogels demonstrate effective self-healing and stimuli-responsive luminescence.
• The findings provide insights into the design of advanced functional materials for sensing and smart applications.