Rapid and Tough Hydrogel Adhesion Enabled by Calcium-Based Metal-Organic-Framework Nanoplates

Nanohesives, such as silica nanoparticles and metal oxide nanoparticles, have recently demonstrated considerable potential for hydrogel adhesion. However, the application of a wide variety of metal-organic frameworks (MOFs) as nanohesives remains seldom reported. Here, the synthesis of 2D calcium-based MOF (Ca-MOF) nanoplates is reported via a simple one-pot approach at room temperature. Rapid, robust, and reversible adhesion between two hydrogels can be achieved by the Ca-MOF nanoplate suspensions. During the adhesion process, interfacial ethanol and TEA are absorbed by the hydrogel through its swelling, forming a Ca-MOF nanoplate multilayer at the interface, which contributes to strong cohesion. Meanwhile, polymer strands adsorbed onto the surface of the Ca-MOF nanoplates and penetrated into the MOF interior, thereby enhancing the interfacial adhesion. Moreover, by adjusting synthesis conditions, including the type of calcium source, calcium ion to terephthalic acid (Ca²⁺/BDC) ratio, and TEA concentration, the morphology of Ca-MOF nanostructures is easily controlled, enabling modulation of the material's adhesive properties. Additionally, biological tissues such as porcine skin can also be glued using Ca-MOF nanoplate suspensions. This strategy represents a rapid, straightforward, and efficient approach for the adhesion of gels or tissues, paving the way for innovative nanodhesive designs.