Spatially confined hydration for robust underwater adhesion.

Area of Science:

• Materials Science
• Surface Chemistry
• Adhesion Science

Background:

• Underwater adhesion is challenging due to water's dual role as a bonding agent and failure cause.
• Existing adhesives struggle with performance degradation in aqueous environments.

Purpose of the Study:

• To develop a novel adhesive tape that effectively utilizes interfacial water for robust underwater adhesion.
• To engineer an adhesive that maintains performance in harsh conditions through controlled hydration.

Main Methods:

• Development of confined hydration adhesive tape (CHAT) with controlled water penetration depths (sub-8-micrometer).
• Utilizing hydrophobic nanodomains and hydration-activated hydrogen bonds for interfacial strength.
• Multiscale experimental validation and molecular dynamics simulations.

Main Results:

• CHAT achieved an interfacial toughness of 6 kJ/m², significantly exceeding literature benchmarks and commercial tapes.
• The adhesive demonstrated stability across a wide pH range (1-13) and in saline conditions.
• Water was identified to act as a catalyst, reorganizer, and decoupler at the interface.

Conclusions:

• CHAT successfully harnesses interfacial water as a design element for high-performance underwater adhesion.
• The technology offers a paradigm shift from compromising with water to utilizing it for enhanced adhesive properties.
• Potential applications span marine, biomedical, and industrial sectors requiring reliable wet adhesion.