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What is graphene?

Graphene is a material made of carbon atoms that are bonded together in a repeating pattern of hexagons. Graphene is so thin that it is considered two dimensional. Graphene's flat honeycomb pattern gives it many extraordinary characteristics, such as being the strongest material in the world, as well as one of the lightest, most conductive and transparent. Graphene has endless potential applications, in almost every industry (like electronics, medicine, aviation and much more).

An ideal graphene sheet image

The single layers of carbon atoms provide the basis for many other materials. Graphite, like the substance found in pencil lead, is formed by stacked graphene. Carbon nanotubes are made of rolled graphene and are used in many emerging applications from sports gear to biomedicine.

What is graphene oxide?

As graphene is expensive and relatively hard to produce, great efforts are made to find effective yet inexpensive ways to make and use graphene derivatives or related materials. Graphene oxide (GO) is one of those materials - it is a single-atomic layered material, made by the powerful oxidation of graphite, which is cheap and abundant. Graphene oxide is an oxidized form of graphene, laced with oxygen-containing groups. It is considered easy to process since it is dispersible in water (and other solvents), and it can even be used to make graphene. Graphene oxide is not a good conductor, but processes exist to augment its properties. It is commonly sold in powder form, dispersed, or as a coating on substrates.

Graphene Oxide structure

Graphene oxide is synthesized using four basic methods: Staudenmaier, Hofmann, Brodie and Hummers. Many variations of these methods exist, with improvements constantly being explored to achieve better results and cheaper processes. The effectiveness of an oxidation process is often evaluated by the carbon/oxygen ratios of the graphene oxide.

Graphene oxide uses

Graphene Oxide films can be deposited on essentially any substrate, and later converted into a conductor. This is why GO is especially fit for use in the production of transparent conductive films, like the ones used for flexible electronics, solar cells, chemical sensors and more. GO is even studied as a tin-oxide (ITO) replacement in batteries and touch screens.

Graphene Oxide has a high surface area, and so it can be fit for use as electrode material for batteries, capacitors and solar cells. Graphene Oxide is cheaper and easier to manufacture than graphene, and so may enter mass production and use sooner.

GO can easily be mixed with different polymers and other materials, and enhance properties of composite materials like tensile strength, elasticity, conductivity and more. In solid form, Graphene Oxide flakes attach one to another to form thin and stable flat structures that can be folded, wrinkled, and stretched. Such Graphene Oxide structures can be used for applications like hydrogen storage, ion conductors and nanofiltration membranes.

Graphene oxide is fluorescent, which makes it especially appropriate for various medical applications. bio-sensing and disease detection, drug-carriers and antibacterial materials are just some of the possibilities GO holds for the biomedical field.

Buy Graphene Oxide

Graphene oxide is relatively affordable and easy to find, with many companies that sell it. It does, however, get confusing since different companies offer products that vary in quality, price, form and more - making the choice of a specific product challenging. If you are interested in buying GO, contact Graphene-Info for advisement on the right GO for your exact needs!

Further reading

Latest Graphene Oxide news

Graphene oxide-based biofoam uses sunlight to clean water

Oct 12, 2016

A team of scientists at Washington University has developed a technique for using sheets of graphene oxide to obtain drinkable water using sunlight; The technique involves heating dirty water to a boil - creating purified steam that can be collected and safely consumed.

Water treatment method using rGO image

The team has devised a method of heat localization using bilayered biofoam composed of bacterial nanocellulose (BNC) and reduced graphene oxide (RGO). The bilayer structure was created by growing Gluconacetobacter hansenii bacteria in the presence of graphene oxide flakes.

Graphene, GO and rGO grown onto silicon chips could pave way to biosensors and electronics

Sep 19, 2016

Researchers at North Carolina State University have developed a technique that enables the integration of graphene, graphene oxide (GO) and reduced graphene oxide (rGO) onto silicon substrates at room temperature by using nanosecond pulsed laser annealing. The advance may open the door to the possibility of creating new electronic devices, such as smart biomedical sensors.

New technique integrates graphene, graphene oxide and reduced graphene oxide onto silicon chips at room temperature

In this new technique, the researchers start with a silicon substrate. They top that with a layer of single-crystal titanium nitride, using domain matching epitaxy to ensure the crystalline structure of the titanium nitride is aligned with the structure of the silicon. They then place a layer of copper-carbon alloy on top of the titanium nitride, again using domain matching epitaxy. Finally, the researchers melt the surface of the alloy with nanosecond laser pulses, which pulls carbon to the surface.

Graphene Handbook

Graphene oxide flakes welded together to create tough, porous material suitable for bone implants

Sep 11, 2016

Researchers at Rice University, along with colleagues in Texas, Brazil and India, have found that flakes of graphene oxide, welded together into a solid material, could be advantageous for bone implants. The team used used spark plasma sintering to weld flakes of graphene oxide into porous solids that compare favorably with the mechanical properties and biocompatibility of titanium, a standard bone-replacement material.

GO flakes welded together for bone implants imageA focused ion beam microscope image shows 3-D graphene layers welded together in a block

The researchers stated that their technique will give them the ability to create highly complex shapes out of graphene in minutes using graphite molds, which they believe would be easier to process than specialty metals. They also said that spark plasma sintering is being used in industry to make complex parts, generally with ceramics. "The technique uses a high pulse current that welds the flakes together instantly. You only need high voltage, not high pressure or temperatures". The material they made is nearly 50% porous, with a density half that of graphite and a quarter of titanium metal. But it has enough compressive strength—40 megapascals—to qualify it for bone implants. The strength of the bonds between sheets keeps it from disintegrating in water.

Graphene oxide enables thermoacoustic speakers

Sep 11, 2016

Researchers at Korea Advanced Institute of Science and Technology (KAIST) have developed a new graphene oxide-based speaker design said to be specifically targeted for the mobile audio market. The speaker does not require an acoustic box to produce sound.

The researchers used graphene in a relatively simple, two-step process that yielded a thermoacoustic speaker. Thermoacoustics is based on the idea that sound can be produced by the rapid heating and cooling of a material instead of through vibrations.

Microwave process produces high-quality graphene

Sep 05, 2016

Researchers at Rutgers University have demonstrated a simple microwave-based method for producing high-quality graphene, that can be used in next-gen electronic and energy devices. The proposed microwave treatment is said to produce exceptionally high quality graphene with properties approaching those of pristine graphene.

The team found that heating exfoliated graphene oxide for one second in a 1,000-watt microwave oven (like those used in households across the world) can eliminate virtually all of the oxygen from graphene oxide, yielding graphene in a simple and cost-effective way.