Graphene Oxide: Introduction and Market News - Page 32

The Spanish Graphenea, along with Russian and Spanish collaborators, have shown that adding graphene to alumina improves the ceramic's wear resistance and decreases friction. The result is expected to soon find uses in real products, as graphene and its derivatives seem to be biocompatible and in addition carry a low cost.

Alunima (an oxide of aluminium) has been long in use in biomedical applications such as load-bearing hip prostheses and dental implants, due to its high resistance to corrosion, low friction, high wear resistance and strength. This recent study describes the dry sliding behavior of a graphene/alumina composite material and compares it to regular alumina. The wear rate of the advanced composite was 50% lower than that of pure alumina, while the friction coefficient was reduced by 10%. This finding is made even more astonishing by the fact that the concentration of graphene in the final product is only 0.22% by weight. The type of graphene used for the study is Graphenea's standard graphene oxide. 

Back in 2013, Rice scientists developed a simple method to reduce coal into graphene quantum dots (GQDs). Now, these Rice researchers have found a way to engineer these GQDs for specific semiconducting properties in two separate processes.

The researchers' work demonstrates precise control over the graphene oxide dots' band gap, the very property that makes them semiconductors. By sorting the QDs through ultrafiltration, it was found possible to produce quantum dots with specific semiconducting properties. The second process involved direct control of the reaction temperature in the oxidation process that reduced coal to quantum dots. The researchers found hotter temperatures produced smaller dots that had different semiconducting properties. The dots in these experiments came from treatment of anthracite, a kind of coal. The processes produce batches in specific sizes between 4.5 and 70 nanometers in diameter.

Scientists at the Natural Science Foundation and the Hospital-Public Cross-Link Project of Shanghai Jiao Tong University discovered that graphene oxide might be helpful in eliminating antibiotic-resistant bacteria that causes tooth decay and gum disease.

Graphene oxide is able to inhibit the growth of certain bacterial strains with minimal harm to cells. The researchers tested it against three different species of bacteria that are also linked to tooth decay and gum disease. Findings showed that graphene oxide effectively slowed the growth of the pathogens.

Researchers from the Bourns College of Engineering at the University of California, Riverside investigated a strategy to improve lithium-sulfur batteries' performance by creating nano-sized sulfur particles, and coating them in glass.

Lithium-sulfur batteries have been attracting attention thanks to their ability to produce up to 10 times more energy than conventional batteries, but one of the main roadblocks to implementing them is a the tendency for lithium and sulfur reaction products (called lithium polysulfides) to dissolve in the battery’s electrolyte and travel to the opposite electrode permanently, which causes the battery’s capacity to decrease over its lifetime. The scientists designed a cathode material in which silica (glass) cages trap polysulfides.. The team used an organic precursor to construct the trapping barrier.

Scientists at the University of Manchester found that graphene oxide may act as an anti-cancer agent that selectively targets cancer stem cells (CSCs). In combination with existing treatments, this could eventually lead to tumor shrinkage as well as preventing the spread of cancer and its recurrence after treatment.

The team prepared a variety of graphene oxide formulations for testing against six different cancer types - breast, pancreatic, lung, brain, ovarian and prostate. The flakes inhibited the formation of tumor sphere formation in all six types, suggesting that graphene oxide can be effective across a large number of different cancers, by blocking processes which take place at the surface of the cells. The researchers suggest that this may deliver a better overall clinical outcome when used in combination with conventional cancer treatments.

A recent study performed at Rice University explored the toxicity of different nanomaterials. A major difficulty in assessing nanomaterial toxicity is that there are many different varieties of nanomaterials and it is too costly to test all of them using traditional methods. The goal of the study was to develop a low-cost, high-throughput method to solve this problem.

The scientists achieved this goal by testing nanomaterials on a worm called Nematode C. Elegans. They designed assays that can test hundreds of nanomaterials in a week. These assays test the effects of each nanomaterial on thousands of worms. The material cost for each assay is only about 50 cents. As a demonstration, they applied their technology to test 20 nanomaterials and found that most of them showed some degree of toxicity. This method can serve effectively as a rapid initial screen to prioritize a few nanomaterials for more expensive, dedicated toxicology testing.

University of Central Florida spin-off Garmor will take part in the NPE2015 Startup Garage and showcase its low-cost graphene oxide and reduced graphene oxide in addition to products made with graphene oxide polymer and fiberglass composites that can be used in a variety of applications ranging from automotive, aerospace, and military to consumer electronics, medical, and construction.

The company will also share the methods developed for the smooth dispersion of graphene into both polar and non-polar plastics. According to Garmor, the company’s partnership with the University of Central Florida (UCF) has played an integral role in perfecting a method to optimize the incorporation of graphene in various polymers, composite materials and coating.

Researchers at the Indian Banaras Hindu University (BHU) designed a sensitive and specific graphene oxide-based electrochemical biosensor for detection of specific micro-particles in blood samples and predict the risk of heart attack or brain stroke.

The scientists explain that certain processes that take place in the body prior to brain stroke or cardiac arrest cause the release of microparticles to the blood, which can be detected by the sensor to predict an imminent stroke or heart attack.

A simple way of cleaning water of various contaminants (from lead and mercury to dye and antibiotics) was shown in a proof-of-concept study at Monash University (that also involved MIT and Bristol University), using graphene oxide and magnets.

The method relies on strong magnets that draw charged particles out of water as it flows through a pipe. The particles are attached to tiny sheets of graphene oxide, which attract a huge range of toxins. Graphene oxide's ability to sponge metal ions made the new system a promising way of treating mine tailing dams.

Researchers at the Centre for Advanced Structural Ceramics at Imperial College London (ICL) cooperated with teams from the University of Warwick, the University of Bath, and the Universidad de Santiago de Compostela to use graphene oxide (GO) and reduced graphene oxide (rGO) together with small amounts of a responsive polymer (a polymer that changes upon activation of a 'chemical switch'), to formulate water based ink or pastes for 3D printing applications.

The scientists say that their formulations sport the required flow and physical properties for 3D printing (namely, the ability to flow through miniature nozzles but set immediately after that), for a technique called direct ink writing (DIW), robocasting or direct write assembly (DWA). This technique is based on the continuous deposition of a filament following a computer design.