A dual pH-responsive supramolecular gelator with aggregation-induced emission properties

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Chemistry

Background:

• Aggregation-induced emission (AIE) materials offer unique optical properties.
• Developing responsive organogelators is crucial for advanced functional materials.
• Zwitterionic moieties can drive self-assembly and impart responsiveness.

Purpose of the Study:

• To synthesize and characterize a novel dual pH-responsive supramolecular organogelator.
• To investigate the aggregation-induced emission (AIE) properties of the designed material.
• To explore the responsive behavior of the organogelator to external stimuli.

Main Methods:

• Functionalization of AIE-active aromatic thioethers with zwitterionic binding sites.
• Fabrication of supramolecular organogels through self-assembly.
• Characterization of gel-sol transitions induced by pH, temperature, and mechanical stress.
• Spectroscopic analysis to confirm fluorescence properties and emission changes.

Main Results:

• A dual pH-responsive organogelator with AIE properties was successfully synthesized.
• The self-assembled fibrillar gel network exhibited strong fluorescence (λem = 490 nm).
• Addition of acid or base induced a reversible gel-to-sol transition, accompanied by a loss of fluorescence.
• The organogel also demonstrated thermo- and mechanoresponsive behavior.

Conclusions:

• The designed supramolecular organogelator exhibits excellent dual pH-responsiveness and AIE characteristics.
• The material's ability to switch between fluorescent gel and non-fluorescent sol states is controllable via pH.
• The combined thermo- and mechanoresponsiveness expands its potential applications in smart materials.