Indirect Adhesion of Hydrogels via the Radical Polymerization Mediated by N,N,N,N-Tetramethylethylenediamine and Ammonium Persulfate

Recently, developing superior adhesive hydrogel systems is in demand because it is important when hydrogel materials are used for applications in engineering, medical, and other fields. Among the adhesive gel systems, the ones for which adhesion can be controlled indirectly have high potential for various applications in the medical and engineering fields because they have merits compared to the systems that need to be regulated directly at the adhesive interfaces when we need to make materials adhere at places that are difficult to touch. In this manuscript, we report the adhesive system which can be regulated indirectly by the reaction of N,N,N ',N '- tetramethylethylenediamine (TMEDA) and ammonium persulfate (APS) inside the gel networks. Applying this system, a step-by-step adhesion, in which adhesive timing can be controlled, and a multiple adhesion, which can adhere multiple gel pieces at once, are constructed. These indirect and continuous adhesions will help us use hydrogels for constructing artificial biomaterials and other various applications.