Interfacial Mechanics of Polymer Nanocomposites

Abstract

Polymer nanocomposites containing nanosized reinforcements produce versatility and multifunctionality that lead to diverse and expanded applications compared to conventional composites. One defining feature of nanocomposites is that the nanoscale size and huge specific surface area create enormous interfaces which dictate the critical overall performance of composite materials. From mechanical points of view, critical issues for the realization of full potential of nanofillers are how to monitor the load transfer process and evaluate load-bearing capability of fillers in composites, what factors govern the interfacial deformation and failure modes at different hierarchy levels, and what the impact of the van der Waals interface will be on the overall mechanics of nanocomposites. Here, we take carbon nanomaterials (e.g., carbon nanotubes, graphene and its chemical derivates) as examples, and summarize the recent progress in theoretical modeling, numerical simulations, and experimental characterizations of buried interfaces within carbon nanomaterial-based polymer composites featuring hierarchical structures. State-of-the-art experimental methods and techniques for quantifying key interface mechanical parameters are outlined. In addition, the impact of interfaces/interphases on the mechanical properties of nanofillers, polymer matrix as well as nanocomposites are respectively discussed in detail. A deep understanding of the factors governing the interface mechanics is further provided, affording an opportunity for the interface engineering through the physical and chemical strategies.