How is graphene created

Graphene and its related materials exhibit excellent mechanical properties. Graphene is strongest material, because of superior mechanical properties of graphene. It is important note that mechanical properties are depends on purity of graphene sheets.

Optical properties of graphene are highly related to the electronics properties. As mentioned earlier that graphene exhibits excellent electronics properties and this phenomenon indicates graphene possesses better optical properties.

Graphene is at can most full transparent materials as it can absorb 2. Because of graphene materials exhibits behaviour which enable graphene to extraordinary optical properties. One can get more information related optical properties of graphene from literature [ 36 ]. Thermal conductivity of graphene is depending on the diffusive and ballistic conditions at higher and lower temperature ranges respectively. Better thermal conductivity of graphene materials is highly depending on quality of graphene sheets.

More details of thermal properties of graphene are available from literature [ 37 ]. In chemical reaction point of view pure form of graphene is mostly not reactive. Chemical properties of graphene are critically influenced by its surface characteristics and thickness of graphene layers. Single layer graphene materials are highly chemically reactive then the multi-layer graphene materials.

Reactiveness of graphene materials are controlled by nitrene chemistry methodology [ 38 , 39 ]. Graphene is intelligent material which exhibits excellent properties used for various industrial applications. Some of the notable applications where graphene started using to create the parts are given as follows. One can found the importance of electronics in most of the industrial applications from medical to mechanical to optical to energy.

Conductivity property of electronics need to high for making electronics devices efficient and effective for usage in real world applications. Graphene is one of the advanced materials that exhibits high conductivity which considered as ideal for high speed electronics.

However, commercial applications of graphene have in initial stages only. Graphene is zero band gap material, more studies needed for of usage industrial applications. Research groups indicating that graphene field is advancing fast to create high speed graphene transistors for applying consumer electronic devices very soon. Data storage is one of the important areas of research. Investigators are developing the powerful small size hard drives to store higher capacity of data.

Researchers suggested that replacing indium tin oxide electrodes with polymers and graphene oxide exhibit write-read-read-rewrite features. Graphene based storage devices are 10 times more powerful than the currently available storage drives. Making small size storage devices is not an issue but increasing capacity levels of storage devices is much importance task.

With applications of graphene oxide devices will create big difference in modern industrial environments. Liquid crystal display LCD smart window is flexible device which consist of a layer of liquid crystals sandwiched between two flexible electrodes made of flexible polymer and graphene. These materials are brittle in nature and limited availability in the world. Usage of graphene in producing flexible smart devices like mobiles and tablet devices is an important research area due to its excellent properties.

Present days electronics are occupying almost every industrial application. Energy storage devices are highly required in every electronics to delivering high electric currents within short time. Supercapacitor is one of the important energy storage devices which utilizes high internal surface area to store charge to delivers higher currents compared to normal capacitors.

Graphene can be highly suitable for making supercapacitors due to its higher internal area property. More research attempts are performing to create graphene-based supercapacitors for many advanced applications. Solar energy is one of the alternatives, and usage is increasing due to shortage of fusil fuels. Solar cell is important element in solar device which plays critical role to absorb energy from sun light. Presently, platinum-based electronics are using to produce solar cells or photovoltaic cells.

In this method, a mixture of gases - in which at least one gas contains carbon — is heated until a plasma has formed. Mass flow meters and controllers are used in CVD processes to dose gases and liquids accurately. By using Chemical Vapour Deposition large sheets of graphene can be produced.

Some of the precursors are liquids that need to be evaporated first, to be used in the CVD process in its gaseous form. This can be achieved by using highly accurate flow instruments. A deviation in the plasma can cause defects in the graphene layer. Defects can be impurities in the 2D structure that can change the unique properties of the material.

Research for high quality graphene by using atmospheric pressure plasma-based techniques Our Spanish distributor, Iberfluid Instruments S. A, recently cooperated with the University of Cordoba in a research to investigate the opportunities regarding graphene production on a large scale by using a plasma based technique under atmospheric pressure.

In this research ethanol was evaporated with the use of Bronkhorst evaporation system, the so-called Controlled Evaporation and Mixing CEM system, to form a plasma. With the use of an evaporation system liquids are being evaporated directly to create the right gas for the plasma. A possible setup of such an evaporation system can consist of a CEM system with an additional liquid flow meter i.

An evaporation system like the Bronkhorst CEM system can deliver excellent performance in terms of stability and accuracy. This resulting material is called reduced graphene oxide, or RGO for short.

In this case, hydrazine is a reducing agent, which is oxidized by its reaction with the graphene oxide. For all its high-tech capacities, graphene is surprisingly easy to make at home—in very small quantities.

The only raw materials needed are graphite for instance, the broken-off point of a standard Number 2 pencil and some fairly robust adhesive tape. Sticking the tape onto the surface of the graphite and pulling sharply will peel off a flake of carbon, and successive rounds of flaking will reduce the thickness of the flake until it is down to a single-atom layer. Methane, a carbon-rich gaseous compound with which we humans are very familiar, can be reacted with copper at high temperatures to produce graphene.

Simply heat the copper to about 1, degrees Celsius and expose it to the methane gas. There are two big problems with this method: It takes a long time to make even a little graphene, and the quality of the graphene produced is not very good. David Boyd at the California Institute of Technology, along with his research collaborators, has found a way to improve on the CVD approach so that it will work with lower temperatures and produce a higher quality graphene.

They, too, use copper and methane, but they add a bit of nitrogen to improve the layering of the graphene on the copper. In this method, energy still needs to be added, but not nearly as much. Global industry has considerable experience with CVD, so it should be possible to eventually automate the process on a large scale; the goal is to produce centimeters or even meters of high-quality graphene at a time.

For the remarkable wonders of graphene to be realized, it must be produced in massive amounts—cheaply. Are dangerous chemicals, complex machines, and multistep chemical reactions and processes too complex for your tastes? Then consider this approach, discovered at Kansas State University, where they produced graphene by creating an explosion.

Have you ever built a spud gun? Basically, if you take a one- to two-meter-long PVC pipe, create a combustion chamber at one end using a spark plug and a quick-sealing endcap, stuff a potato in the other end, and fill the now sealed combustion chamber with a flammable vapor hair spray is good , then you have a spud gun.

Once the potato is in place, the chamber fueled with hair spray and then sealed, you can point the far end of the PVC pipe toward your target and discharge your battery to cause the spark plug to spark.

The resulting small explosion creates a pressure wave that dislodges the potato from the end of the combustion chamber, moving it up the nozzle of the PVC pipe, and into the air—often launching it tens of meters into the distance. The physics of what happens in the combustion chamber is very similar to the method that scientists at Kansas State University used to create graphene, in what may become a scalable process that could be a step toward mass production.

Instead, they were trying to make something called a carbon soot aerosol gel for use in insulation and water purification systems. And not just a little bit of graphene. Granted, nothing is ever that simple, but this approach sounds like a good one to pursue in conjunction with other methods.

Instead of PVC pipe, the scientists used a more robust chamber for their combustion event. They replaced the hair spray with acetylene or ethylene gas mixed with oxygen. They did use a spark plug to create the combustion, just as we did with our spud gun. The fuel, the acetylene or ethylene gas, was turned into graphene and some other carbon detritus.

This method calls for heating the oil to break it down into its constituent carbon atoms, and then quickly cooling the carbon in thin layers on nickel foil. Besides being less costly, the soybean-oil technique is safer than methods that use vacuum processing or explosive compressed gas. Then there is the soybean oil method—as in, the same stuff you can use at home when you cook. A research team in Australia found a way to use everyday soybeans to produce single-layer graphene sheets on top of a nickel substrate—potentially making sheets with large areas all at one time.

The process is a variation of the CVD process described previously, but with a significant difference: This one is done in ambient air no specialized vacuum chambers, etc.

The secret is in the nickel foil catalyst used and in carefully controlling the temperature of the process to prevent, as much as possible, the formation of carbon dioxide. It is worth mentioning that the team investigated other metal foils, including copper, and no others promoted the formation of graphene. Only nickel did. When all else fails, why not just go home and use your blender to make the wonder material of the 21st century?

With only a little more processing required to separate the newly formed graphene sheets, Coleman and his colleagues found that they could produce several hundred grams per hour using a fairly modest set of mixing equipment in a 10,liter vat. A search of the scientific literature reveals a myriad of techniques that can produce graphene of varying quality.

What they have in common is complexity, energy, and the fact that they can only achieve the production of small quantities of graphene, which then needs to be separated out from the other reaction products. To date, there is no simple production technique that results in large quantities of high-quality graphene.

For the truly remarkable wonders of graphene to be realized, it must be produced in massive amounts—cheaply. Would you like to buy a 10 millimeter x 10 millimeter monolayer of graphene flakes on a silicon substrate? How about a 60 millimeter x 40 millimeter piece of monolayer graphene on copper?

There are companies specializing in graphene that will sell individual users samples at very reasonable prices. Making graphene, though, is not trivial. The best mass-market graphene comes from chemically exfoliated, natural, mined graphite, and companies that own interests in graphite mines are already establishing themselves as players in this graphene revolution, leveraging their preferential access to raw materials in order to increase share prices.

But without agreement in the market or regulation, how would buyers determine which so-called graphene product would be best for their needs? Unfortunately, only a few of these tests are within the reach of a typical company laboratory; the others require expensive equipment that needs to be run and maintained by specially trained technicians. The three cheapest tests to perform determine the size of a particular flake, the degree of defects within a given sample, and the elemental makeup of a sample.

Clusters of silicon atoms embedded in a graphene sheet appear as yellow shapes in the center of this colored scanning transmission electron micrograph. The hexagonal, latticelike arrangement of graphene atoms holds the silicon atoms in place so they can be imaged.

This measurement is made with what is called Raman spectroscopy, which measures vibrational patterns in the sample. Oxidation of the carbon-carbon bonds in graphene by oxygen opens up graphene to environmental degradation, and the introduction of other atoms onto the graphene surface causes various properties to change dramatically. For example, adding even a single hydrogen atom to the graphene structure causes the graphene to become magnetic. Mined graphite would contain residues of the formerly living matter from which it was created, and these elements would ultimately detract from the quality of the graphene through one mechanism or another.

Facebook facebook Twitter twitter Reddit reddit Comment. James Maynard , Tech Times 21 June , pm. Do not reproduce without permission.

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