Interface mechanics in carbon nanomaterials-based nanocomposites

Carbon nanomaterials (e.g., carbon nanotubes and graphene) have been deemed as versatile building blocks to create a novel generation of nanocomposites desired for a variety of commercial applications. Different from that of the conventional fiber-based composites, the enormous interfacial areas, van der Waals forces dominated interface interactions as well as multiple scale load transfer mechanism would greatly impact the mechanical behaviors of carbon nanomaterials-based composites. Besides the widely concerned nanofiller-matrix interface, the filler-filler interface has to be considered in nanocomposites. The main challenge is how to monitor the load transfer process and evaluate load-bearing capability of fillers in composites. Here, we summarize the recent progress in experimental characterization of atomic-scale interface mechanics, and clarify its importance on the reinforcement of nanocomposites. We also highlight the significance of competed mechanism between intrinsic mechanical strength of nanofillers and interfacial shear effect, allowing the delicate design of nanocomposites that deliver desired properties.