Friction of low-dimensional nanomaterial systems

Abstract

When material dimensions are reduced to the nanoscale, exceptional physical mechanics properties can be obtained that differ significantly from the corresponding bulk materials. Here we review the physical mechanics of the friction of low-dimensional nanomaterials, including zero-dimensional nanoparticles, onedimensional multiwalled nanotubes and nanowires, and two-dimensional nanomaterials-such as graphene, hexagonal boron nitride (h-BN), and transition-metal dichalcogenides-as well as topological insulators. Nanoparticles between solid surfaces can serve as rolling and sliding lubrication, while the interlayer friction of multiwalled nanotubes can be ultralow or significantly high and sensitive to interwall spacing and chirality matching, as well as the tube materials. The interwall friction can be several orders of magnitude higher in binary polarized h-BN tubes than in carbon nanotubes mainly because of wall buckling. Furthermore, current extensive studies on two-dimensional nanomaterials are comprehensively reviewed herein. In contrast to their bulk materials that serve as traditional dry lubricants (e.g., graphite, bulk h-BN, and MoS 2 ), large-area highquality monolayered two-dimensional nanomaterials can serve as single-atom-thick coatings that minimize friction and wear. In addition, by appropriately tuning the surface properties, these materials have shown great promise for creating energy-efficient self-powered electro-opto-magneto-mechanical nanosystems. State-of-theart experimental and theoretical methods to characterize friction in nanomaterials are also introduced.

Understanding Interlayer Contact Conductance in Twisted Bilayer Graphene

“…As illustrated in Figure a–d, three domains (SLG, BLG, and Cu) showing different friction responses in each panel can be clearly distinguished. Friction forces of both SLG and BLG domains are much smaller than that of bare copper substrate since an ideal graphene film is atomically smooth and has no dangling bond, resulting in low shear strength . Friction force of SLG is larger than that of BLG, which is consistent with previous literature .…”

Toughening mechanisms and mechanical properties of graphene nanosheet-reinforced alumina

“…The combination of these actions allowed the GNS to stretch to a substantial extent during crack opening stage. Depending on its elasticity, an extensibility of 20% strain has been reported for graphene [42,43]. This analysis highlights the direct role of GNS towards arresting the crack progression and stress dissipation through crack-bridging toughening mechanism (Fig.…”

2D-nanomaterials for controlling friction and wear at interfaces

“…Some of the most recent work in this area is reviewed here and more thorough reviews, specifically on graphene, can be found elsewhere [52][53][54].…”