Harnessing Water Molecules for Strong Underwater Adhesion.

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Science

Background:

• Underwater adherable materials are crucial for marine exploration.
• Existing adhesives struggle with a balance between interfacial bonding and cohesive strength in wet conditions.

Purpose of the Study:

• To develop a water-induced, toughening underwater adhesive that transforms water from a hindrance to a performance enhancer.
• To resolve the trade-off between interfacial bonding and cohesive strength in underwater adhesives.

Main Methods:

• Designed an adhesive with both hydrophilic and hydrophobic units for adaptive adhesion to rough surfaces.
• Utilized water molecules to activate in situ polymer chain interactions, inducing phase separation and enhancing mechanical properties.
• Evaluated interfacial toughness, transparency, recyclability, and long-term stability.

Main Results:

• Achieved a high underwater interfacial toughness of 1602 ± 85 J m⁻².
• Demonstrated simultaneous robust interfacial bonding and high energy dissipation during peeling.
• The adhesive exhibited transparency, recyclability, and long-term stability in aqueous environments.

Conclusions:

• The developed water-induced toughening strategy effectively enhances underwater adhesive performance.
• This approach offers a new paradigm for designing advanced underwater adhesive materials by leveraging water molecules.
• The adhesive's properties make it suitable for diverse marine applications.