Graphene-Info: the graphene experts

A team of researchers from China has reported a novel strategy to 'stitch' together reduced graphene oxide (rGO) nanosheets into ultra-strong, tough, and highly conductive graphene films using only small amounts of cross-linker. They show that the bridging of long-chain π-π bonding agent between neighboring rGO nanosheets can provide substantial improvement in multiple properties including tensile strength, toughness, electrical conductivity, EMI shielding capability, and resistance to mechanical damage.

"Our graphene films not only demonstrate a record tensile strength of almost 1.1 GPa, but exceptional abilities to absorb mechanical energy, transport charge, and shield electromagnetic interference that are comparable to or even superior to graphene films annealed at much higher temperatures," says Qunfeng Cheng, a professor at Beihang University in Beijing. "Our process uses abundant natural graphite as a raw material at room temperature. This novel strategy can provide an inspiration for converting low-priced graphite powders into much higher performance macroscopic graphene films for diverse commercial uses in the future."

Researchers at the University of Cambridge and Jiangnan University in China have developed graphene-enhanced wearable electronic components incorporated directly into fabrics. The devices could be used for flexible circuits, healthcare monitoring, energy conversion, and other applications.

The researchers have shown how graphene and other related materials can be directly incorporated into fabrics to produce charge storage elements such as capacitors, paving the way to textile-based power supplies which are washable, flexible and comfortable to wear.

Researchers at Queen’s University in Kingston, Canada have developed a simple yet effective exfoliation process for producing few-layer graphene nanoplatelets (FL-GNPs). Utilizing this one-step, chemical and solvent-free process the researchers were able to convert graphite flakes (+100 mesh, purity >97%) into FL-GNPs at a high yield (90%) and to subsequently form thermoplastic/FL-GNPs composites with improved electrical and mechanical properties.

TEM image of isolated FL-GNP

The exfoliated graphene nanoplatelets had a high specific surface area (325 m²/g), an aspect ratio above 500 (approximate lateral dimensions of 2µm and thickness of 3.5 nm), and a Raman D/G ratio of 0.3; indicating a structure with few defects. The flexural modulus of polyamide/FL-GNP composites containing 15 volume % FL-GNPs improved from 1850 MPa to 5,080 MPa while the electrical conductivity rose from 5x10-14 S/m to 21 S/m. Surface-coating the FL-GNPs through the addition of a coating agent during the last stages of the exfoliation process rendered the FL-GNPs more hydrophilic, thus, forming stable dispersions in water.

Versarien has updated that it is now fully operational at its new U.S office and laboratory facility in Houston, Texas, which is designed to act as a hub for the Company’s activities in North America.

The establishment of this U.S hub has already enabled the Company to accelerate its progress in North America with various new partners, in addition to the work it has been undertaking with the US National Graphene Association and various existing collaboration partners in the region.

A research group at the University of Tartu in Estonia has been working on a graphene-enhanced sensor nose for five years and presented their latest prototype in February at the Barcelona World Mobile Congress in the Graphene Pavilion.

The prototype does not look anything like a mobile phone yet; it is quite big and would not fit in a pocket. But it already has a processor, Bluetooth, GPS and touchscreen. ‘We met many people there who really needed it and were a little disappointed that we didn’t have the product ready yet,’ says Raivo Jaaniso, head of the laboratory and a senior research fellow at the University of Tartu. But big breakthroughs always require time and the project is halfway complete, with plenty of work and experimenting ahead for the next four years.

Zen Graphene Solutions recently announced that it has been awarded a $1,000,000 CAD (around $742,600 USD) grant that will accelerate ZEN’s graphene-enhanced concrete research and development project.

According to Zen, the grant may potentially help achieve the goal to provide cement-based composite products to the Ontario market by possibly early 2020. The grantor will reimburse 50% up to a maximum of $1,000,000 spent by ZEN on relevant expenses directly related to graphite purification, graphene production research, concrete additive research and large-scale graphene-enhanced concrete testing.

Global Graphene Group, and its subsidiary Angstron Energy (AEC) has developed a new graphene/silicon composite anode material (GCA-II-N) which can increase the capacity of Li-Ion batteries while reducing the battery's size and weight. AEC current market focus is on electronic bikes and consumer electronics, but is also working with Tier-1 electric cars and trucks makers.

AEC tells us that by wrapping single-layer graphene (or r-GO) around silicon nanoparticles, the volume expansion/contraction of the Silicon during the battery's charge/discharge cycle can be cushioned by the flexibility and mechanical strength of the graphene. The graphene sheets also form a 3D conductive network which ensures good electrical contacts between the Silicon particles and the current collector.