Mechanical properties of graphene papers

Abstract

Graphene-based papers attract particular interests recently owing to their outstanding properties, the key of which is their layer-by-layer hierarchical structures similar to the biomaterials such as bone, teeth and nacre, combining intralayer strong sp 2 bonds and interlayer crosslinks for efficient load transfer. Here we firstly study the mechanical properties of various interlayer and intralayer crosslinks via first-principles calculations and then perform continuum model analysis for the overall mechanical properties of graphene-based papers. We find that there is a characteristic length scale l 0 , defined as 0 / 4 Dh G , where D is the stiffness of the graphene sheet, h 0 and G are the height of interlayer crosslink and shear modulus respectively. When the size of the graphene sheets exceeds 3l 0 , the tension-shear (TS) chain model that are widely used for nanocomposites fails to predict the overall mechanical properties of the graphene-based papers. Instead we proposed here a deformable tension-shear (DTS) model by considering the elastic deformation of the graphene sheets, also the interlayer and intralayer crosslinks. The DTS is then applied to predict the mechanics of graphene-based paper materials under tensile loading. According to the results we thus obtain, optimal design strategies are provided for designing graphene papers with ultrahigh stiffness, strength and toughness.

Mechanics of metal-catecholate complexes: The roles of coordination state and metal types

“…Our affine network model suggests the tunability of network mechanics by controlling either the crosslink ( k , k ′) or polymer ( K ). In experiments, change from k to k ′ could be established by modulate the metal-coordination state, and the effective stiffness K could be elevated from entropy-controlled value ~ k B T / L 2 for a flexible polymer chain ( L is its size), to much higher values in semiflexible nanostructures, e.g carbon nanotubes and graphene16394041. By integrating these thoughts, high-performance responsive materials could be accomplished.…”

Traction–separation laws and stick–slip shear phenomenon of interfaces between cellulose nanocrystals

“…Using composite theories such as the shear-lag model (Liu et al, 2012;Liu and Xu, 2014;Wei et al, 2012), one can predict the mechanical performance of CNC thin films based on the interlayer shear modulus, G and Young's modulus of the CNCs, E. The models developed for the traction potentials are particularly useful as they can be used to obtain values of G as shown in Figure 7A. Using experimentally reported values of the elastic modulus of CNCs in literature (Moon et al, 2011), the shear-lag model (Liu et al, 2012;Liu and Xu, 2014;Wei et al, 2012) can be employed to estimate the effective elastic modulus, E eff , of a CNC thin film.…”

“…Using experimentally reported values of the elastic modulus of CNCs in literature (Moon et al, 2011), the shear-lag model (Liu et al, 2012;Liu and Xu, 2014;Wei et al, 2012) can be employed to estimate the effective elastic modulus, E eff , of a CNC thin film. Using specific values of the interlayer shear modulus as reported in the SI, an effective elastic modulus can be estimated for an aligned, CNC thin film as illustrated in Figure 7B.…”

Static and dynamic response of sector-shaped graphene sheets

“…Nano or micron scaled plates and graphene of arbitrary shapes have been widely used in modern industries such as biomedical devices, nano electro mechanical applications, biochemical purpose, mechanical actuators and nano sensors [1][2][3][4][5][6][7]. Nano scaled structures such as beams and plates have been also widely used in micro-electro mechanical systems (MEMS) for high frequency and high sensitive purposes due to their ultra mechanical, thermal and electrical properties.…”