Graphene Oxide: Introduction and Market News - Page 25

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.

A 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.

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.

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.

Last month we launched a new feature - Experts Roundup. In this feature we ask graphene professionals to answer a short graphene related question. Last month's question was "will CVD ever be a viable commercial way to produce graphene?" and we got great response to that. Hopefully this month feature will be just as good.

In the growing field of graphene-enhanced composites, especially plastics, how does graphene oxide fit in? Does it have any significant advantages over graphene?

Ian Fuller, VP business development & engineering, Angstron Materials : I would classify graphene oxide as a functionalized graphene nanomaterial. Functionalization, in general, allows for tailored nanomaterials for applications such as polymer nanocomposites. The oxygen-based groups on the surface of graphene oxide often promote coupling between the polymer and the nanomaterial leading to enhanced properties such as strength and quality of dispersion (however, electrical and thermal conductivity are often reduced). Similarly, other functional groups can be added to the surface of a graphene platelet to customize it for a range of applications and polymers.

The Korean Grapheneall recently started to produce graphene oxide and reduced GO, in a low price that is enabled by the company's new oxidation and purification process that helps to decrease acidic waste. The company set up a factory and started production of GO and rGO in ton scale per month.

Grapheneall's SEM image of GO

The unique purification process is said to be simple and take just one hour, as opposed to many other purification processes that are more time consuming. Grapheneall's production line is an automated system that is able to check and save real-time conditions, which assists the company in controlling the progress of production.

Graphene 3D Lab announced that it will be selling a new single-layer graphene oxide material under the trade name of ORG-GO.

The new material can reportedly be easily dissolved in a variety of organic solvents to achieve ultrahigh concentrations. ORG-GO also boasts outstanding thermal stability. G3L expects that the ORG-GO product line will find numerous applications such as being a reinforcement for polymers and nanocomposites as well as for the preparation of high-performance graphene inks and coatings.

Researchers at A*STAR have designed a low-cost, stable and ultrafast graphene oxide-based responsive humidity sensor that is said to be easy to manufacture, overcoming the challenge of producing a simple, fast and highly sensitive version. The ability to monitor and control humidity levels using accurate and reliable sensors is essential for efficient manufacturing and storage practices as well as everyday life.

Unlike most humidity sensors, which are electronic and require a power supply, GO-based colorimetric sensors respond to humidity levels by changing color that can be easily observed. For greater accuracy, the change in color can be quantitatively measured by analyzing the reflection spectra of the sensor. Because the GO sensor operates at the atomic level, it can rapidly respond to moisture changes.

The Sixth Element Materials Technology is a Chengzhou, China based company that develops and produces graphene and graphene oxide materials. The company recently opened a sales office in Europe, and appointed Bernhard Münzing as sales director.

Bernhard was kind enough to participate in an interview with graphene-info. Bernhard is an industrial engineer with a focus on chemistry, who has held different positions in sales, materials management, marketing and business development in big as well as medium sized chemical companies.

Q: We understand that The Sixth Element (T6E) currently produces graphene flakes and graphene oxide, in a 100 ton/year plant in Chengzhou. Is that correct? Can you tell us anything regarding the current production plant?

Researchers at Washington University have managed to use graphene oxide sheets to create a biofoam that can transform dirty water into drinking water. Their hope is that in countries where there is a lot of sunlight, it'll be possible to take dirty water, evaporate it using this material, and collect fresh water.

This new method combines bacteria-produced cellulose and graphene oxide to form a bi-layered biofoam. The production process is said to be extremely simple, and the nanoscale cellulose fiber network produced by bacteria has excellent ability to move the water from the bulk to the evaporative surface while minimizing the heat coming down. The material is a bi-layered structure with light-absorbing graphene oxide filled nanocellulose at the top and pristine nanocellulose at the bottom. When suspended this on water, the water is actually able to reach the top surface where evaporation happens.

William Blythe, Uk-based chemicals manufacturer, has announced the addition of graphene oxide to its portfolio of innovative products. According to the company, this step was made possible when the company moved graphene oxide to large lab scale manufacture and reached kilogram capacity production.

William Blythe is currently able to offer graphene oxide as a dispersion in deionised water. The percentage dispersions are agreed upon with customers on an individual basis. WB's current capabilities allow the manufacture of up to 20 kg of powdered graphene oxide equivalent per annum with the intention of increasing to tonnage scale in the next 6 12 months.