Nanoparticle Organization Controls Their Potency as Universal Glues for Gels

Nanoparticles have been recently shown to act as universal glues for both synthetic and biological gels, providing a tunable, cheap, and general solution to the centuries-old problem of sticking soft materials together. The design of new adhesive solutions based on this platform, however, requires an understanding of how nanoparticles' design parameters concur to determine the final adhesion strength. Here, we use coarse-grained modeling and molecular dynamics simulations to investigate such links. Our main aim is to show that, at experimentally relevant concentrations, adhesion is strongly influenced by the way nanoparticles organize at the interface, resulting in non-monotonous reinforcement behavior. Our findings represent an important step toward rationalizing this new class of nanoparticle-based adhesives.