Gluing polymer interfaces with nanoparticles: insights from molecular dynamics

In recent years, nanoparticles have been shown to have the potential to answer the centuries-old question of how to mechanically strengthen an interface between soft materials. A deeper understanding of the mechanism and parameters resulting in the mechanical reinforcement, or lack thereof, would help rationalize experimental findings and, ultimately, guide the design of adhesive solutions. Building on our previous work on polymer in bad solvent conditions [DOI: 10.1021/acs.nanolett.8b00586], we investigate the trends, and the fundamental drivers of, the mechanical properties of polymer interfaces glued with spherical nanoparticles. Using a coarse-grained model, we simulate polymer network structures with different degrees of swelling. The interface between two networks is filled with nanoparticles, and the overall system is then uni-axially strained to construct the stress-strain curve for a given set of parameters. The results from this investigation help disentangling the contributions to the strengthening of the interface and can be used as a guide to experimental design of nanoparticles-based adhesives.