Adaptive microgel films with enhancing cohesion, adhesion, and wettability for robust and reversible bonding in cultural relic restoration

Abstract

Hydrogel adhesives hold significant promise for applications in flexible intelligent systems and biomedical engineering. However, reconciling high toughness with strong, durable, and repeatable interfacial adhesion remains a daunting challenge. Herein, a new strategy was proposed involving the utilization of physically crosslinked microgels to fabricate a high-toughness adhesive microgel film, optimizing cohesion, adhesion, and wettability to significantly enhance interfacial adhesion performance. The microgels were synthesized using polyzwitterions and acrylic acid through inverse emulsion method, leveraging on their intrinsic ability to readily form abundant non-covalent interactions. The resultant microgel-based adhesive film, formed through physical crosslinking and chain entanglement mechanisms, exhibited a tensile strength of 0.34 MPa, an exceptional elongation at break of 1107.79 %, and a toughness of 2842.17 kJ/m³. Furthermore, this adhesive film demonstrated a remarkable adhesive strength of 1740.9 kPa, with its adhesion performance retaining stable and effective even under extreme environmental conditions, including elevated temperatures and complete submersion in aqueous environments. In contrast to conventional hydrogel adhesives, this microgel system achieves superior mechanical robustness, interfacial adhesion, and environmental resistance, highlighting their promising potential candidate for applications in cultural heritage conservation.