Robust and dynamic underwater adhesives enabled by catechol-functionalized poly(disulfides) network

Natl Sci Rev. 2022 Jul 25;10(2):nwac139. doi: 10.1093/nsr/nwac139. eCollection 2023 Feb.

Abstract

Developing molecular approaches to the creation of robust and water-resistant adhesive materials promotes a fundamental understanding of interfacial adhesion mechanisms as well as future applications of biomedical adhesive materials. Here, we present a simple and robust strategy that combines natural thioctic acid and mussel-inspired iron-catechol complexes to enable ultra-strong adhesive materials that can be used underwater and simultaneously exhibit unprecedentedly high adhesion strength on diverse surfaces. Our experimental results show that the robust crosslinking interaction of the iron-catechol complexes, as well as high-density hydrogen bonding, are responsible for the ultra-high interfacial adhesion strength. The embedding effect of the hydrophobic solvent-free network of poly(disulfides) further enhances the water-resistance. The dynamic covalent poly(disulfides) network also makes the resulting materials reconfigurable, thus enabling reusability via repeated heating and cooling. This molecule-engineering strategy offers a general and versatile solution to the design and construction of dynamic supramolecular adhesive materials.

Keywords: adhesives; dynamic polymers; iron-catechol complexes; non-covalent crosslink; supramolecular materials.