Tunnelling effect is a possible mechanism to explain the apparent large electric conductivity and nonlinear electric behavior of graphene-reinforced nanocomposites with polymer matrix. In this work, a numerical modeling framework is proposed to evaluate the effective electric conductivity in polymer composites reinforced with graphene sheets, taking into account the electrical tunnelling effect...

Flexible and ultratransparent conductors based on graphene sheets have been considered as one promising candidate for replacing currently used indium tin oxide films that are unlikely to satisfy future needs due to their increasing cost and losses in conductivity on bending. Here we demonstrate a simple and fast electrochemical method to exfoliate graphite into thin graphene sheets, mainly AB-s...

Graphene sheets offer extraordinary electronic, thermal and mechanical properties and are expected to find a variety of applications. A prerequisite for exploiting most proposed applications for graphene is the availability of processable graphene sheets in large quantities. The direct dispersion of hydrophobic graphite or graphene sheets in water without the assistance of dispersing agents has...

We report a new, simple, hydrazine-free, high-yield method for producing single-layer graphene sheets. Graphene sheets were formed from graphite oxide by reduction with simple deionized water at 95 °C under atmospheric pressure. Over 65% of the sheets are single graphene layers; the average sheet diameter is 300 nm. We speculate that dehydration of graphene oxide is the main mechanism for oxyge...

Nanoelectromechanical resonator sensors based on graphene sheets (GS) show ultrahigh sensitivity to vibration. However, many factors such as the layer number and dimension of the GSs will affect the sensor characteristics. In this study, an analytical model is proposed to investigate the vibration behavior of double-layered graphene sheets (DLGSs) with attached nanoparticles. Based on nonlocal ...

Pd-metal graphite (Pd-MG) has a layered structure, where each Pd sheet is sandwiched between adjacent graphene sheets. DC magnetization and AC magnetic susceptibility of Pd-MG have been measured using a SQUID magnetometer. Pd-MG undergoes a superconducting transition at Tc (= 3.63±0.04 K). The superconductivity occurs in Pd sheets. The relaxation of MZFC (aging), which is common to spin glass s...

Tunnel effect is a possible mechanism to explain the apparent large electric conductivity and nonlinear electric behavior of graphene-reinforced nanocomposites with polymer matrix. In this work, a numerical modeling framework is proposed to evaluate the effective electric conductivity in polymer composites reinforced with graphene sheets, taking into account the electrical tunneling effect, whi...

We use first-principles calculations to investigate the geometric, electronic and magnetic properties of metal adatoms on two typical graphene substrates (monolayer and bilayer). Firstly, we study the adsorption behaviors and the doping effects of metal atoms on pristine and defective bilayer graphene sheets (PBG and DBG). It is found that the metal doping in DBG sheets is more stable than that...

The buckling of graphene sheets on substrates can significantly degrade their performance in materials and devices. Therefore, a systematic investigation on the buckling behavior of monolayer graphene sheet/substrate systems is carried out in this paper by both molecular mechanics simulations and theoretical analysis. From 70 simulation cases of simple-supported graphene sheets with different s...