Graphene Essay

While this research is very highly regarded, the quality of the graphene produced will still be the limiting factor in technological applications. Once graphene can be produced on very thin pieces of metal or other arbitrary surfaces (of tens of nanometres thick) using chemical vapour disposition at low temperatures and then separated in a way that can control such impurities as ripples, doping levels and domain size whilst also controlling the number and relative crystallographic orientation of the graphene layers, then we will start to see graphene become more widely utilized as production

Graphene is a form of carbon which has recently been receiving a great deal of attention. Some have come to call it “the wonder material” due to its many extraordinary properties. Although isolated in 2004, graphene's properties had been calculated decades earlier. It consists of a single layer of carbon atoms arranged in a hexagonal lattice. A single sheet of graphene is stronger than steel and yet remains very flexible, retaining all of its properties despite being bent and unbent multiple times. It is able to sustain extremely high electric current densities, is impermeable to all gasses, has a thermal conductivity double that of diamond and a very high electron mobility at room temperature. It is also easily chemically functionalized,

Graphene is the cutting edge material in the field of nanotechnology materials. In recent years, the single layer hexagonal shaped carbon has rocked the world of modern physics and material engineering with its unique electronic properties and manufacturing cost. As a result, extensive researches have been conducted over years in order to discover the new potentials of graphene. In this review, the production method of graphene and the general properties are mentioned briefly. In addition, the applications and drawbacks of the graphene are discussed below. Generally speaking, graphene will be the most suitable candidate to replace silicon in all manners in manufacturing electronic devices as now we are going beyond silicon ages.

Here we report the fabrication of a flexible all carbon field effect transistor (FET) using a low cost, recyclable and biodegradable cellulose paper as both substrate as well as dielectric and pencil graphite as source, drain, channel and gate without using any other expensive, toxic or non-biodegradable materials. The electron and hole mobility’s of FET are observed to be 180 and 200 cm2v-1s-1 respectively which are comparable to the recently reported values of paper FET with polymer dielectric and cellulose composite dielectrics. The FET was utilized as a strain sensor which shows good sensitivity for low strains of both tensile and compressive type. The mobility of the FET increases with increase in compressive strain and decreases with increase in tensile strain. The sensitivity of the FET sensor increases with the increase in the gate voltage.

Rao et al. (2009) discussed that graphene is a fascinating new nanocarbon possessing, single-, bi- or few layers of carbon atoms forming six-membered rings which were investigated by X-ray diffraction, atomic force microscopy, transmission electron microscopy, scanning tunneling microscopy and Raman spectroscopy. The extraordinary electronic, magnetic and electrochemical properties of single and bi layer graphene are unique and unexpected.

The second underlying scattering mode (G-), responsible for the asymmetry, also exhibits a much more significant decrease in width of ~35% G-G (G) from ~20cm-1 to~13cm-1 as we go from the suspended graphene to where the graphene sits on the cavity waveguide structure. Asymmetry in the graphene Raman G-peak has previously been attributed to highly localised charge inhomogeneity within the laser probe area [26], i.e. on the sub-micron scale and it has also already been observed when comparing Raman spectra of suspended graphene with that supported by a substrate [22]. Recent studies of graphene supported by nanostructured surfaces [27] have also revealed a multi-peak fine-structure in the G-band, which was interpreted as being the result of extreme curvature or ‘wrinkling’, similar to what is observed in single wall carbon nanotubes. In this case, the doubly degenerate in-plane E2g optical mode can be split between phonons along the nanotube axis, and those that are perpendicular to it, with the degree of splitting, being a strong function of the nanotube size (i.e. degree of curvature), even in the absence of any externally applied strain [28]. G-peak splitting has also been observed in graphene under uniaxial strain [5] and in isolated Carbon nanotube’s under hydrostatic pressure [29] where the curvature-sensitive lower

The mechanical properties of graphene sheet can be tailored with the help of topological defects. In this research article, the effects of Stone-Thrower-Wales (STW) defects on the mechanical properties of graphene sheet was investigated with the help of molecular dynamics (MD) based simulations. Authors has made an attempt to analyse the stress field developed in and around the vicinity of defect due to bond reorientation and further systematic evaluation has been carried out to study the effect of these stress fields against the applied axial compressive load. The results obtained with the pristine graphene were made to compare with the available open literature and the results were reported to be in good agreement with theoretical and experimental data. It was predicted that graphene with STW defect cannot able to bear compressive strength in zigzag direction, whereas on the other hand it was predicted that graphene sheet containing STW defect can bear higher compressive load in armchair direction, which shows an anisotropic response of STW defects in graphene. From the obtained results it can be observed that orientation of STW defects and the loading direction plays an important role to alter the strength of

In recent years, polymer composites with dielectric constant have been prepared by two routes. The more traditional route is introducing high dielectric constant ceramic fillers, such as BaTiO3, Pb(Zr,Ti)O3, and CaCu3Ti4O12 into the polymer matrix. However, the high loading (usually over 50 vol%) of ceramic fillers required for enhancing dielectric constant inevitably raises the issues of inhomogeneity and aggregation of the ceramic fillers in the polymer matrix, deteriorating the characteristics resulting in poor mechanical properties such as high dielectric loss. Furthermore, the dielectric enhancement is usually low. Another route focuses on dispersing conductive fillers such as graphene, carbon nanotubes (CNTs), conductive fibers, and metal particles into the polymer matrix to achieve percolative systems. As the volume fraction of the conductive fillers increases in the vicinity of the percolation threshold, where the conductive fillers connect with each other to form a continuous conducting path, the

Nanoparticles show different and distinctive properties from the bulk materials and they can be incorporated in different fields such as, biomedicine, catalysis, and energy conversion, so they have gained significant considerations from the researchers in the last two decades. For example, biologist and scientists have just started to apply nano-pattering techniques to create detection systems for genomic studies. On the other hand, engineers and physicists are aiming to shrink the size of transistors and MEMS components by using the method of nanofabrication in order to make high performance electronic devices. In general, material properties are completely dependent on the structure, so changing the macroscopic bulk properties, such as

In the article “A Preliminary Study on the Effect of Macro Cavities Formation on Properties of Carbon Nanotube Bucky-Paper Composites” by Ludovic Dumée, a researcher at Dreakin University’s institute for Frontier Materials, “over the last decade carbon nanotubes have attracted a lot of interest and efforts were made to incorporate them efficiently into composite material structures (Dumée 558). Dumée substantiates this statement by providing a number of data from research that has been conducted in the last few decades. He provides charts and diagrams from some of his own tests that show that carbon nanotubes can be easily processed as bucky-papers, which are entangled meshes of nanotubes (Dumée 628). Researchers and engineers are currently studying bucky papers and investigating their properties. Current research shows that bucky papers exhibit auspicious properties and they are strong and flexible structures to engineer and examine (Bahr 6537).

Due to outstanding properties, graphene got more attention by the scientific community; all its exceptional properties are owing to hexagonal monolayer of honeycomb lattice packed with carbon atoms. The mechanical properties of graphene have been investigated using various experimental, theoretical and computational approaches. By experimental based work, Lee et al. [1] estimated the mechanical properties of graphene such as Young’s modulus of about 1.0 ± 0.1 TPa and fracture strength of 130 ± 10 GPa. Frank et al. [2] estimated Young’s modulus of 0.5 TPa for 2 to 8nm thickness of graphene sheets. Zhang et al. [3] measured Young’s modulus of 0.89 TPa for single layer graphene sheet. Besides experimental work, numerous theoretical and computational studies have been carried out to investigate mechanical properties of graphene. By orthogonal tight-binding method Zhao et al. [4] estimated Young’s modulus of 1.01 ± 0.03 and fracture strength and strain of 107 GPa and 0.20 in zigzag direction and 90 GPa and 0.13 in armchair direction respectively. By Ab initio calculation Liu et al. [5] estimated young’s modulus of 1.05 TPa and also estimated uniaxial tensile stress of 121

It should be noted that some materials exhibit more than one of the above properties and It is

First, Nano Development in Mexico is on the rise – it’s unregulated and risks spinning out of control

Although graphite is a form of carbon, and carbon itself cannot conduct electricity, graphite is able to conduct electricity. This is because graphite contains electrons that are able to detach and move around the graphite, therefore carrying a charge that can allow electricity to be conducted. Graphite is a great material used for pencils because it is a soft material that has strong bonds between the carbon atoms but weak bonds between the layers of these strong bonds as shown in the diagram. These layers slide off easily on to the paper which is how something shows up on the paper. Lead pencils are made from a combination of clay and graphite, and the hardness of these pencils are identified by using letters as codes.

In recent years, studies on the electrical and dielectric properties of metal-polymer nanocomposites have attracted much attention in view of their application in electronic and electrical devices. Electrical conduction in polymers has been studied