Mechanosensitive non-equilibrium supramolecular polymerization in closed chemical systems

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Chemical Engineering

Background:

• Chemical fuel-driven supramolecular systems exhibit out-of-equilibrium functions but generate waste and require open systems.
• Existing systems face limitations in waste management and operational environment.

Purpose of the Study:

• To develop a non-equilibrium supramolecular polymerization system that operates in a closed environment.
• To create a mechanosensitive dissipative system with minimal waste generation.
• To explore the fabrication of transient supramolecular structures and their functionalities.

Main Methods:

• Utilized viologens and pyranine in the presence of hydrazine hydrate within a closed system.
• Initiated self-assembly of pyranine into nanotubes via air oxidation of viologens upon shaking.
• Investigated disassembly of nanotubes by a reducing agent, yielding nitrogen as the sole byproduct.
• Introduced chiral molecules to create chiral transient supramolecular helices.
• Employed ultrasound as a specific mechanical stimulus for pattern generation.

Main Results:

• Successfully demonstrated non-equilibrium supramolecular polymerization in a closed system.
• Achieved spontaneous disassembly of self-assembled structures, producing only nitrogen waste.
• Fabricated chiral transient supramolecular helices and observed shake-induced fluorescence modulation.
• Generated template-free, reproducible patterns using ultrasound.
• Showcased the system's versatility with the polymerization of amphiphilic naphthalenetetracarboxylic diimide.

Conclusions:

• Developed a novel, mechanosensitive, closed-system supramolecular polymerization with minimal waste.
• The system offers tunable functionalities, including transient structure formation and fluorescence modulation.
• Demonstrated potential for creating advanced materials and patterns through mechanical stimuli.