A Near‐Infrared Photothermal‐Responsive Underwater Adhesive with Tough Adhesion and Antibacterial Properties

Abstract Developing tunable underwater adhesives that possess tough adhesion in service and easy detachment when required remains challenging. Herein, a strategy is proposed to design a near infrared (NIR) photothermal‐responsive underwater adhesive by incorporating MXene (Ti 3 C 2 T x )‐based nanoparticles within isocyanate‐modified polydimethylsiloxane (PDMS) polymer chains. The developed adhesive exhibits long‐term and tough adhesion with an underwater adhesion strength reaching 5.478 MPa. Such strong adhesion is mainly attributed to the covalent bonds and hydrogen bonds at the adhesive‐substrate interface. By making use of the photothermal‐response of MXene‐based nanoparticles and the thermal response of PDMS‐based chains, the adhesive possesses photothermal‐responsive performance, exhibiting sharply diminished adhesion under NIR irradiation. Such NIR‐triggered tunable adhesion allows for easy and active detachment of the adhesive when needed. Moreover, the underwater adhesive exhibits photothermal antibacterial property, making it highly desirable for underwater applications. This work enhances the understanding of photothermal‐responsive underwater adhesion, enabling the design of tunable underwater adhesives for biomedical and engineering applications.