Strong and Thermo-Switchable Gel Adhesion Based on UCST-Type Phase Transition in Deep Eutectic Solvent.

Area of Science:

• Materials Science
• Polymer Chemistry
• Adhesion Science

Background:

• Achieving strong and reversible hydrogel adhesion is challenging.
• Hydrogel adhesives often lack environmental stability due to dehydration.

Purpose of the Study:

• To design reversible adhesive gels with enhanced mechanical properties and environmental stability.
• To explore a new temperature-induced switching mechanism for tunable adhesion.

Main Methods:

• Utilized poly(benzyl acrylate) (PBnA) polymer in menthol:thymol deep eutectic solvents (DESs) to observe UCST-type thermosensitive behavior.
• Incorporated a peptide crosslinker to improve energy dissipation and mechanical properties.
• Investigated the thermal reversible adhesion and switching ratio of the eutectogel.

Main Results:

• Demonstrated UCST-type thermosensitive behavior of PBnA in DESs, enabling temperature-controlled adhesion.
• Achieved a high adhesion strength of 0.627 MPa with a switching ratio of 14.0.
• The DES-based gel exhibited excellent environmental stability and repeated switching capabilities.

Conclusions:

• Developed a novel eutectogel with strong, reversible, and environmentally stable adhesion.
• The gel's tunable adhesion via temperature and peptide crosslinking offers significant advantages.
• Successfully demonstrated applications in soft grippers and gecko-inspired climbing robots.