Graphene Oxide: Introduction and Market News - Page 40

Turkey's Grafen Chemical Industries has selected Angstron Materials to supply them with graphene materails for a polymer nanocomposite application for electromagnetic shielding material.

Grafen will buy both pristine and oxidized graphene products from Angstron and plans to commercialize the EMI product for full-scale production.

Researcher from Northwestern University developed a new way to amplify signals in hybrid graphene oxide and CNT electrochemical sensors. They use a process called Magneto-Electrochemical Immunoassay to achieve that.

The researchers designed the new hybrid material to correlate the available metal ions with analyte concentration. They used magnetic particles encapsulated in inert coating of silicon dioxide which were later coated with gold (gold is chemically inert and bio-compatible). This process is efficient, fast and cost-effective.

Researchers from Rice University and Lomonosov Moscow State University discovered that Graphene Oxide can quickly remove radioactive material from contaminated water. They found out that graphene oxide bind quickly to natural and human-made radionuclides and condense them into solids.

This discovery is obviously useful in contaminated site cleanups (such as the Fukushima nuclear plants), but is also useful in hydraulic fracturing (fracking) for oil and gas recovery and rare earth mineral mining.

Researchers from Monash University (Australia) have managed to grow 3D graphene "towers" that make graphene more elastic. The new 3D material supports 50,000 times its own weight, springs back into shape after being compressed by up to 80% and has a very low density. The material still retains graphene's conductivity.

To develop the new material, the researchers used ice crystal as templates to grow the graphene towers from graphene oxide flakes. The technique was adapted from freeze casting which involves growing layers of soluble graphene oxide between forming ice crystals. By partially stripping the oxygen coating before freeze casting, they could enhance the bonding between adjacent flakes in the network, producing much stronger materials then before. The individual graphene sheets are neatly aligned, forming an ordered network of hexagonal pores.

Unlike graphene, graphene-oxide (GO) has a bandgap, but has poor electronic properties (due to disorganized arrangement of atoms). Now researchers from the University of Wisconsin—Milwaukee have developed a method to make ordered GO. They hope that this method will enable "ideal bandgap" carbon based devices to be used as transistors, sensors and optoelectronic devices.

The researchers made a device made from layers of oxygen-poor graphene sandwiched between layers of GO, and then annealed (heated) it. The resulting device (shown on the right of the image above) has a more complex and ordered structure (you can see this as the extra rings in the image).

AZ Electronic Materials have entered into a licensing and sponsored research agreements with William Marsh Rice University in the field of graphene nanoribbons (GNRs) for application to electronic and advanced optical devices. AZ will gain exclusive world-wide rights to several patent families invented by Dr. James Tour and his working group at Rice, covering preparation methods and application of GNRs.

This technology could potentially enable low-cost functionalize GNR production from commercially available carbon sources such as CNTs. The method developed at Rice is reductively open CNTs to provide high quality, highly conductive GNRs. This method also provides an easy way to chemically functionalize them at their edges, which leads to greatly enhanced stability of coating formulations without deteriorating the performance. This allows the GNRs to be formulated in solvents common to electronic device manufacturing processes, which can be coated on substrates by industry-known methods. AZ also licensed Dr. Tour's high-yield approaches to graphene oxide.

Researchers from Northwestern University developed a new method to manufacture large-scale nanofluidic devices, using graphene-oxide. These devices feature thin channels that can transport ions (and so high electric current), and so are useful to make batteries and water purification systems.

The idea is to stack up graphene-oxide sheets to create a flexible paper-like material. Such a paper features tens of thousands of very useful channels as a gap forms naturally between neighboring sheets, and each gap is a channel through which ions can flow. Using simple, regular scissors the paper is cut into any shape you want (in the experiment they simple used rectangles). The paper shape is then incased in a polymer and holes are drilled to expose the ends. The holes are filled with electrolyte solution (a liquid containing ions) to complete the device.

Researchers from the Hebrew University of Jerusalem, Israel, developed a new coating technology a few years ago as part of their sol-gel chemistry in hydrogen-peroxide-rich solutions research. This technology uses nanometric metal oxide dots. Now this technology is used to synthesize graphene-tin oxide composites based Li-Ion battery anodes. This new application was developed in collaboration with Singapore's National Research Foundation under its CREATE program.

Graphene-tin oxide is attractive as an anode material due to its high charging capacity, thigh conductivity and the fact that the graphene oxide and tin oxide nanocrystals are in close contact. But synthesizing those composites is difficult because the only way to coat an ultra-thin layer of tin oxide nanocrystals on a sheet of graphene oxide is slow, expensive and needs a high temperature. But the new coating technology is done at room temperature and is simple and thus less expensive.

Graphenea has launched an online store, and the company now offers several graphene materials including CVD graphene films (on SiO₂, copper and any substrate that the customer provides), graphene oxide and reduced graphene oxide. The company is also building a distribution network in main graphene markets (such as the US, Japan and Korea).

Graphenea has a pilot line with a capacity of 50,000 cm²/year and they plan to expand it during 2013. Graphenea says that their customer list includes Nokia, Philips, Corning and ASML.

Researchers from the Rensselaer Polytechnic Institute have developed a new graphene based anode that can be charged or discharged 10 times faster than conventional graphite anodes currently used in today’s lithium-ion batteries. To create the new anode material, the researchers took a sheet of graphene-oxide paper and then introduced defects (using a laser or a camera flash) on the material.

The graphene paper, after being damaged, has expanded five-fold in thickness, which means that there were large voids between the graphene sheets. The lithium ions can use the cracks in the paper to quickly traverse the entire sheet - which means faster charges or discharges of the battery.