Pure graphene in the form of few-layer graphene (FLG) - 1 to 6 layers - is biocompatible and non-cytotoxic. This makes FLG an ideal material to incorporate into dental polymers to increase their strength and durability. It is well known that graphene has high mechanical strength and has been shown to enhance the mechanical, physical and chemical properties of biomaterials. However, for commerci...

in the present study, the effect of various weight fractions of graphene nanoplatelet (gpl) on flexural fatigue behavior of epoxy polymer has been investigated at room temperature and generally the temperature was monitored on the surface of specimen during each test. the flexural stiffness of grapheme nano-platelet/epoxy nanocomposites at 0.1, 0.25 and 0.5 wt. % as a main effective parameter o...

The local interaction between graphene and a host substrate strongly determines the actual properties of the graphene layer. Here we show that scanning tunneling microscopy (STM) can selectively help to visualize either the graphene layer or the substrate underneath, or even both at the same time, providing a comprehensive picture of this coupling with atomic precision and high energy resolutio...

TiO(2)-based photocatalysis has been widely used to decompose various organic pollutants for the purpose of environmental protection. Such a "green" photochemical process can ultimately degrade organic compounds into CO(2) and H(2)O under ambient conditions. We demonstrate here its extended application on the engineering of single- or few-layer graphene. Using a patterned TiO(2) photomask, we h...

Recent dramatic progress in studying various two-dimensional (2D) atomic crystals and their heterostructures calls for better and more detailed understanding of their crystallography, reconstruction, stacking order, etc. For this, direct imaging and identification of each and every atom is essential. Transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) are...

Loose graphene sheets, one to a few atomic layers thick, are often observed on freshly cleaved HOPG surfaces. A straightforward technique using electrostatic attraction is demonstrated to transfer these graphene sheets to a selected substrate. Sheets from one to 22 layers thick have been transferred by this method. One sheet after initial deposition is measured by atomic force microscopy to be ...

High-energy collective electronic excitations (plasmons) in freestanding multilayer graphene are studied by momentum-resolved electron energy-loss spectroscopy (EELS). For normal incidence, only the high-energy plasmon band is excited and we measure a blueshift of the π -plasmon dispersion with increasing thickness. The observed transition between two-dimensional and three-dimensional behavior ...

Using a model of oscillating dipoles, we simulate the intensity of the G-band in the Raman signal from structures consisting of graphene, separated by an arbitrary buffer layer from a substrate. It is found that a structure with an optimized buffer layer refractive index and thickness exhibits a Raman signal which is nearly 50 times more intense than that from the same structure with a non-opti...

We investigate the use of perfluorodecyltrichlorosilane-based self-assembled monolayer as seeding layer for chemical vapour deposition of HfO2 on large area CVD graphene. The deposition and evolution of the FDTS-based seed layer is investigated by X-ray photoelectron spectroscopy, Auger electron spectroscopy, and transmission electron microscopy. Crystalline quality of graphene transferred from...

The sensitivity of graphene based devices to surface adsorbates and charge traps at the graphene/dielectric interface requires proper device passivation in order to operate them reproducibly under ambient conditions. Here we report on the use of atomic layer deposited aluminum oxide as passivation layer on graphene field effect devices (GFETs). We show that successful passivation produce hyster...