Tough Supramolecular Glasses Enabled by Frustrated Non-Covalent Complexation

Area of Science:

• Materials Science
• Polymer Chemistry
• Supramolecular Chemistry

Background:

• Supramolecular glasses, amorphous materials cross-linked non-covalently, face a trade-off between vitrification and mechanical properties.
• Existing materials struggle to balance glass transition temperature with toughness.

Purpose of the Study:

• To introduce and validate a novel strategy,
• "frustrated non-covalent complexation" (FNC), to enhance supramolecular glass performance.
• To overcome the inherent limitations in mechanical properties of traditional supramolecular glasses.

Main Methods:

• Designed squaramide-based monomers with sterically hindering isopropyl groups.
• Investigated the impact of steric hindrance on hydrogen-bonding interactions and material packing.
• Characterized the mechanical properties, including toughness and adhesion, of the resulting supramolecular glasses.

Main Results:

• The FNC strategy led to loosely packed hydrogen-bonded domains and shifted interaction dominance to squaramide-ester hydrogen bonds.
• Achieved a 4.3-fold increase in mechanical toughness compared to a non-frustrated control.
• Demonstrated enhanced interfacial adhesion, showing potential as an impact-resistant coating.

Conclusions:

• Frustrated non-covalent complexation is a powerful paradigm for designing high-performance supramolecular materials.
• This approach effectively enhances mechanical toughness and interfacial adhesion in supramolecular glasses.
• The strategy offers a new pathway for developing advanced amorphous materials with improved durability.