Graphene Oxide: Introduction and Market News - Page 31

Researchers from the VIT University in India managed to synthesize and characterize unique graphene oxide reinforced composites (prepared by colloidal blending), with potential for benefiting applications like electronics with desired dielectric properties, such as embedded capacitors. The composite's excellent stability and anti-corrosive properties make it suitable for marine and naval applications.

The composite, referred to as PEDOT-TMA/PMMA/GO, were examined by various means, namely UVVis spectroscopy, X-ray diffraction, thermogravimetric analysis, Fourier transforms infrared spectroscopy, FT-Raman spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy. It was demonstrated that the GO was homogeneously dispersed in the polymer matrix. An increase in surface roughness as a function of GO loading was also found, as well as a significant improvement in the thermal stability of composites. The composites show high values of dielectric constant and low values of dielectric loss.

Brown University researchers developed a simple method of creating environments on which to culture cells using graphene, that relies on a technique that makes small wrinkles in graphene sheets. These textured surfaces for culturing cells in the lab manage to copy the intricate environment in which cells grow in the body.

Cell culture is usually done in the lab in petri dishes and on other flat surfaces. The body, however, creates much more complex environments for cells to grow. Research has shown that a cell’s physical surroundings can influence its shape, physiology, and even the expression of its genes, so scientists are looking for ways of culturing cells in lab conditions that are a bit more complex and close to body-made environments. The surfaces might also be used to test drugs in the lab, or perhaps as biomimetic surfaces for implantable tissue scaffolds or neural implants.

Researchers at the Lawrence Livermore National Laboratory created graphene aerogel microlattices with an engineered architecture using a 3D printing technique known as direct ink writing. These lightweight aerogels have high surface area, excellent electrical conductivity, mechanical stiffness and exhibit supercompressibility (up to 90% compressive strain). In addition, the researchers claim that these 3D printed graphene aerogel microlattices show great improvement over bulk graphene materials and much better mass transport.

A common problem in creating bulk graphene aerogels is the occurrence of a largely random pore structure, thus excluding the ability to tailor transport and additional mechanical properties of the material for specific applications such as batteries and sensors. Making graphene aerogels with engineered architectures is greatly assisted by 3D printing, which allows to design the pore structure of the aerogel, permitting control over many properties. This development, as per the scientists, could open up the design space for using aerogels in novel and creative applications.

Researchers at Australia's Swinburn University of Technology designed a graphene-based technique to create a 3D pop-up floating display. The scientists created nanoscale pixels of refractive index (the measure of the bending of light as it passes through a medium) made of reduced graphene oxide in a process that does not involve heat, which they say is important for the subsequent recording of the individual pixels for holograms and naked-eye 3D viewing.

The team explains that by changing the refractive index, it is possible to create many optical effects. This new technique can be leveraged to achieve compact and versatile optical components for controlling light and can create the wide-angle display necessary for mobile phones and tablets. The scientists believe that this new generation digital holographic 3D display technology could also have applications for military devices, entertainment, remote education, and medical diagnosis as well as lay foundation for future flexible and wearable display devices and transform them for 3D display.

Ionic Industries, a subsidiary of Strategic Energy Resources, announced the completion of an independent marketing report on the potential of its graphene-based SuperSand product. This product is meant to be a potential substitute for activated carbon and can offer equal or better performance at a lower (or at least comparable) cost.

The report yielded positive findings that support the company's decision to make SuperSand the first of its products to be produced by its planned graphene oxide manufacturing pilot plant, for which an engineering study is almost complete (with commencement of construction of the pilot plant planned for later in 2015).

Researchers at the Massachusetts Institute of Technology and Harvard Medical School studied the extent to which graphene oxide is biocompatible, and discovered that it is not toxic to cells (up to a certain concentration). Graphene oxide may thus be suitable for use in medical devices and implants for next-generation biosensors, implantable electronics or even tissue engineering scaffolds.

In their tests, the scientists found that reducing the degree of graphene oxidation resulted in the material infiltrating and clearing cells faster. They also observed that after injection, the graphene oxide particles coalesced to form an implant-like material in the tested mice. The scientists' study showed that over the short term, the body responds to graphene oxide in much the same way it does to other biomaterial implants that are known to be safe.

NanoXplore announced that it is producing Graphene Oxide in industrial quantities. The Graphene Oxide is being produced in the same 3 metric tonne per year facility used to manufacture NanoXplore's standard graphene grades and derivative products such as a unique graphite-graphene composite suitable for anodes in Li-ion batteries.

Graphene Oxide (GO) is similar to graphene but with significant amounts of oxygen introduced into the graphene structure. GO, unlike graphene, can be readily mixed in water which has led people to use GO in thin films, water-based paints and inks, and biomedical applications. GO is relatively simple to synthesize on a lab scale using a modified Hummers' method, but scale-up to industrial production is quite challenging and dangerous. This is because the Hummers' method uses strong oxidizing agents in a highly exothermic reaction which produces toxic and explosive gas. NanoXplore has developed a completely new and different approach to producing GO based upon its proprietary graphene production platform. This novel production process is completely safe and environmentally friendly and produces GO in volumes ranging from kilogram to tonne quantities.

Scientists at the Indian Institute of Engineering Science and Technology (IIEST) discovered that reduced graphene oxide (rGO) can be used in a unique sensor to detect a deadly cancer-causing food toxin with high sensitivity.

The toxin, Aflatoxin B1, is a common contaminant in peanuts, chillies, cottonseed meal, corn, rice and other grains. Produced by a fungus, it is a potent liver carcinogen that damages the immune system in humans and animals.

Researchers at the Amrita Institute of Medical Sciences and Research Centre in India demonstrated that graphene oxide nanoflakes can enhance the properties of artificial composites to provide supportive scaffolds that encourage bone repair.

According to the scientists, a great challenge is to design a biomaterial that should match the properties of native healthy bone, Properties like biocompatibility, chemical composition, porosity, degradation and mechanical stability that are critical in determining the success of the biomaterial. Traditional treatments for bone fractures that fail to heal spontaneously are bone grafts taken from elsewhere in the patient's body, causing pain and potential damage to the harvested site.

Researchers at China's Tsinghua University used ion-selective membranes of ultrathin graphene oxide (GO) to develop a novel, ion-selective but highly permeable separator for significantly improving both the energy density and power density of lithium-sulfur batteries. This resulted in a highly-stable and anti-self-discharge lithium-sulfur cell.

Polysulfides are materials generated at the cathode side, diffuse through the membrane, react with lithium anode, and shuttle back. During the process, polysulfides dissolve and irreversibly react with metal lithium and organic components, inducing the destruction of the cathode structure, depletion of the lithium anode, and loss of active sulfur materials. Commonly used separators in battery systems are porous polymer membranes, which separate the two electrodes while having little impact on the transportation of ions through the membrane. The researchers' design was of a GO membrane, sandwiched between cathode and anode electrodes, which efficiently prohibited the shuttle of polysulfides through the membrane.