Tunable binary supramolecular interactions enabling biomimetic adhesives with switchable robustness and dynamic...

Area of Science:

• Materials Science
• Polymer Chemistry
• Supramolecular Chemistry

Background:

• Supramolecular adhesives offer tunable properties but integrating high adhesion and rapid response is challenging.
• Existing smart materials often compromise strength for dynamic behavior or vice versa.

Purpose of the Study:

• To design a binary supramolecular system with controllable dual-mode adhesion.
• To investigate the relationship between molecular stoichiometry and adhesive performance.
• To explore self-healing and adaptive capabilities in supramolecular adhesives.

Main Methods:

• Fabrication of a binary supramolecular system using alpha-lipoic acid (αLA) and cyclen.
• Tuning adhesive properties by varying the molar ratio of αLA to cyclen.
• Characterization of adhesion strength, kinetics, underwater performance, and self-healing properties.
• Mechanistic studies involving hydrogen bonding and electrostatic interactions.

Main Results:

• LC0.25 (1:0.25 αLA:cyclen) exhibited ultra-high shear strength (23.48 MPa on Al2O3), underwater adhesion, and biocompatibility.
• LC0.5 demonstrated rapid adhesion kinetics (3.35 MPa on glass in 2 min), temperature sensitivity, and reusability.
• Stoichiometry-dependent balance between hydrogen bonding and electrostatic interactions governs performance switching.
• LC0.25 elastomer showed self-healing capability due to dynamic molecular interactions and a stable network.

Conclusions:

• A simple binary supramolecular system enables dual-mode adhesion through stoichiometric control.
• This strategy allows for the design of adaptive, high-performance adhesives with tunable properties.
• The findings provide a new pathway for developing advanced smart materials for diverse applications.