Deformation-Structure Correlations in Glassy Polymer-Grafted Nanoparticle Assemblies

Composites made from polymer-grafted nanoparticles (PGNs) with entangled canopies can avoid the nanoparticle aggregation common in polymer-nanoparticle blends, and have allowed mechanically robust designs for structural, separation, electronic, and optical applications. Recent studies have elucidated the relationship between PGN architecture (graft density Σ, graft degree of polymerization N, and nanoparticle core radius r₀) and the retention of mechanical strength and polymer-like plasticity (i.e. crazing) below T_g. In parallel, the ARGET-ATRP emulsion-polymerization method has expanded the available composition and quantity of PGNs. Herein, we discuss the correlations between the structure of PGN assemblies derived from ARGET-ATRP and their elasticity, plasticity, and failure mechanisms, with a focus on elucidating the impact of secondary interactions within and between canopies, and the impact of core shape and composition.