Electrochemical interfacial capacitance in multilayer graphene sheets: Dependence on number of stacking layers

2009 ◽  
Vol 11 (9) ◽  
pp. 1729-1732 ◽  
Author(s):  
Da-Wei Wang ◽  
Feng Li ◽  
Zhong-Shuai Wu ◽  
Wencai Ren ◽  
Hui-Ming Cheng
Keyword(s):  
Graphene Sheets ◽  
Multilayer Graphene ◽  
Interfacial Capacitance

Meso-origami: Folding multilayer graphene sheets

2009 ◽  
Vol 95 (12) ◽  
pp. 123121 ◽  
Author(s):  
Steven Cranford ◽  
Dipanjan Sen ◽  
Markus J. Buehler
Keyword(s):  
Graphene Sheets ◽  
Multilayer Graphene

Molecular dynamics calculation of the thermal conductivity coefficient of single-layer and multilayer graphene sheets

2013 ◽  
Vol 55 (4) ◽  
pp. 889-894 ◽  
Author(s):  
A. A. Selezenev ◽  
A. Yu. Aleinikov ◽  
N. S. Ganchuk ◽  
S. N. Ganchuk ◽  
R. E. Jones ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Thermal Conductivity Coefficient ◽  
Single Layer ◽  
Graphene Sheets ◽  
Multilayer Graphene ◽  
Dynamics Calculation

Buckling of Multilayer Graphene Sheets Subjected to Axial Compression Based on a Continuum Mechanics Model

2018 ◽  
Vol 85 (6) ◽  
Author(s):  
Moonhong Kim ◽  
Seyoung Im
Keyword(s):  
Axial Length ◽  
Md Simulations ◽  
Buckling Load ◽  
Single Layer Graphene ◽  
Graphene Sheets ◽  
Multilayer Graphene ◽  
Beam Model ◽  
Shear Rigidity ◽  
Buckling Loads ◽  
Number Of Layers

Buckling of multilayer graphene sheets (MLGSs) subjected to an axial compressive load in plane-strain condition is studied. Closed-form solutions for buckling load of MLGSs are obtained based on a continuum model for MLGSs. Two different kinematic assumptions, which lead to MLGS beam, which was recently proposed by the authors, and the Euler beam, are used to obtain the buckling loads. The obtained solutions yield significantly different buckling loads when the axial length is small. To validate obtained results, molecular dynamics (MD) simulations are conducted, and they show that the MLGS beam model well captures the buckling load of MLGSs. The buckling solution of MLGS beam model provides two interesting facts. First, the buckling load of MLGSs coincides with the Euler buckling load when the length is large. Second, when the number of layers is large, the buckling strain converges to a finite value, and could be expressed as a linear combination of the buckling strain of single-layer graphene and the ratio between the shear rigidity of interlayer and the tensile rigidity of graphene layer. We validate the asymptotic behavior of buckling strain through MD simulations and show that buckling occurs even when the overall thickness is larger than the axial length. Finally, we present a diagram that contains buckling strain of MLGSs according to the boundary conditions, the number of layers, and the axial length.

Graphene Production With Stirred Media Mills

2010 ◽  
Vol 1259 ◽  
Author(s):  
Catharina Knieke ◽  
Angela Berger ◽  
Wolfgang Peukert
Keyword(s):  
Large Scale ◽  
Chemical Properties ◽  
Single Layer ◽  
Single Layer Graphene ◽  
High Yield ◽  
Graphene Sheets ◽  
Multilayer Graphene ◽  
Scale Production ◽  
Graphite Particles ◽  
Media Milling

AbstractSince the discovery of stable graphene sheets by Novoselov und Geim in 2004 the one atom thick carbon material has been attracted great interest because of its outstanding physical, mechanical and chemical properties. Although there had been intensive research to find new ways in the preparation of single-layer graphene sheets in the last few years, especially the large-scale production of graphene still remains challenging. In this paper we present a new approach, which allows the high-yield production of graphene sheets in a simple stirred media milling process. Under mild milling conditions single- and multilayer graphene sheets have been successfully produced from commercial graphite powder in a liquid medium. During the delamination procedure, the graphite particles were stressed between the milling beads. Shear and compressive normal forces can lead under mild milling conditions, i.e. low stress energies, to a continuous mechanical peeling of graphene sheets from the graphite surface. By means of Atomic Force Microscopy a high yield of single- and multilayer graphene sheets was detected. A concentration of exfoliated sheets of 2 wt% starting from a 5 wt% suspension of coarse graphite particles could be determined after a milling time of only 3 h. This concentration is much higher than those, which were reached by most of the known chemical methods. Since stirred media milling can be realized as large-scale process, a high-yield and low-cost production of graphene flakes becomes possible at ambient temperature.

scholarly journals Silicon micro-levers and a multilayer graphene membrane studied via laser photoacoustic detection

2015 ◽  
Vol 4 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Z. Zelinger ◽  
P. Janda ◽  
J. Suchánek ◽  
M. Dostál ◽  
P. Kubát ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Pressure Sensors ◽  
Graphene Sheets ◽  
Multilayer Graphene ◽  
Sensitivity Testing ◽  
Photoacoustic Detection ◽  
Position Sensing ◽  
Graphene Membrane ◽  
Electret Microphone ◽  
Silicon Cantilever

Abstract. Laser photoacoustic spectroscopy (PAS) is a method that utilizes the sensing of the pressure waves that emerge upon the absorption of radiation by absorbing species. The use of the conventional electret microphone as a pressure sensor has already reached its limit, and a new type of microphone – an optical microphone – has been suggested to increase the sensitivity of this method. The movement of a micro-lever or a membrane is sensed via a reflected beam of light, which falls onto a position-sensing detector. The use of one micro-lever as a pressure sensor in the form of a silicon cantilever has already enhanced the sensitivity of laser PAS. Herein, we test two types of home-made sensing elements – four coupled silicon micro-levers and a multilayer graphene membrane – which have the potential to enhance this sensitivity further. Graphene sheets possess outstanding electromechanical properties and demonstrate impressive sensitivity as mass detectors. Their mechanical properties make them suitable for use as micro-/nano-levers or membranes, which could function as extremely sensitive pressure sensors. Graphene sheets were prepared from multilayer graphene through the micromechanical cleavage of basal plane highly ordered pyrolytic graphite. Multilayer graphene sheets (thickness ∼102 nm) were then mounted on an additional glass window in a cuvette for PAS. The movements of the sheets induced by acoustic waves were measured using an He–Ne laser beam reflected from the sheets onto a quadrant detector. A discretely tunable CO2 laser was used as the source of radiation energy for the laser PAS experiments. Sensitivity testing of the investigated sensing elements was performed with the aid of concentration standards and a mixing arrangement in a flow regime. The combination of sensitive microphones and micromechanical/nanomechanical elements with laser techniques offers a method for the study and development of new, reliable and highly sensitive chemical sensing systems. To our knowledge, we have produced the first demonstration of the feasibility of using four coupled silicon micro-levers and graphene membranes in an optical microphone for PAS. Although the sensitivity thus far remains inferior to that of the commercial electret microphone (with an S / N ratio that is 5 times lower), further improvement is expected to be achieved by adjusting the micro-levers and membrane elements, the photoacoustic system and the position detector.

Observation of multilayer graphene sheets using terahertz phase contrast microscopy

Pramana ◽  
2016 ◽  
Vol 88 (1) ◽  
Author(s):  
ZHIKUN LIU ◽  
YANAN XIE ◽  
LI GENG ◽  
DENGKE PAN ◽  
PAN SONG
Keyword(s):  
Phase Contrast ◽  
Graphene Sheets ◽  
Multilayer Graphene ◽  
Phase Contrast Microscopy ◽  
Contrast Microscopy

MULTILAYER GRAPHENE CHLORINE ISOBUTYL ISOPRENE RUBBER NANOCOMPOSITES: INFLUENCE OF THE MULTILAYER GRAPHENE CONCENTRATION ON PHYSICAL AND FLAME-RETARDANT PROPERTIES

2016 ◽  
Vol 89 (2) ◽  
pp. 316-334 ◽  
Author(s):  
D. Frasca ◽  
D. Schulze ◽  
M. Böhning ◽  
B. Krafft ◽  
B. Schartel
Keyword(s):  
Flame Retardant ◽  
Barrier Properties ◽  
Graphene Sheets ◽  
Multilayer Graphene ◽  
Gas Barrier ◽  
Low Concentrations ◽  
Rubber Nanocomposites ◽  
Flame Retardant Properties ◽  
Gas Barrier Properties ◽  
Isoprene Rubber

ABSTRACT In recent years, different nanoparticles have been proposed and successfully introduced as nanofillers in rubber nanocomposites. In this study, multilayer graphene (MLG) is proposed as a nanoparticle that functions efficiently at low concentrations. MLG consists of just 10 or so graphene sheets. Chlorine isobutyl isoprene rubber (CIIR)/MLG nanocomposites with different MLG loadings were prepared using an ultrasonically assisted solution mixing procedure followed by two-roll milling. The incorporation of MLG provides a clear improvement in the rheological, mechanical, curing, and gas barrier properties of the nanocomposites. Adding only 3 phr of MLG to CIIR increased the Young's modulus by more than two times and reduced the permeability of O2 and CO2 by 30%. Higher nanofiller concentrations yielded further improvement in the properties of the nanocomposites. Moreover, CIIR/MLG nanocomposites showed reduced flammability.

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