Researchers at Queen's University develop a novel, scalable and low-cost process to produce defect-free graphene nanoplatelets

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.

Queens University FL-Graphene TEM photo 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.

The EU NanoMaster project report exciting mid results with enhanced graphene capacity

NanoMaster project logoIn December 2011 the EU launched a graphene project called NanoMaster with an aim to develop up-scale processing methods for production of graphene and expanded graphite reinforced thermoplastic masterbatches and compounds. Today the project partners announced that the project is entering its final phase, and is reporting exciting results.

Recently, the project team focused on optimizing and up-scaling the processes for graphene and expanded graphite production, and their subsequent compounding with a range of thermoplastics. They have now achieved a graphene production capacity increase from 50 grams to 2.5 Kg.

KAIST researchers develop new way to make defect-free graphene

Researchers at from Korea's KAIST institute developed a new method to fabricate defect-free graphene. Using this graphene, they developed a promising high-performance anode for Li-Ion batteries.

The method starts with a Pyrex tube and fill it with graphite powder. The open-ended tube is placed in another, larger tube and potassium is added to the gap between the tubes. The tubes are sealed and heated - which causes the potassium to move inside the micropores in the graphite powder - creating a potassium-graphite compound. This is placed in a pyridine solution, which expands the layer and separates them to form graphene nanosheets - which are then exfoliated to create a single graphene sheet.

The original scotch-tape exfoliation process finally fully understood

The recent years interest in graphene started when Andre Geim and Konstantin Novoselov first managed to isolate the material by using the 'scotch-tape' method. This simply and "primitive" method eventually led to their Nobel-Prize in 2010, and the graphene boom started.

But atomic processes behind the micromechanical cleavage in this method have never been really understood - until now. A research team from Russia, the USA and Finland researched the physics, kinetics and energetics behind the regarded this method, using molybdenum disulphide (MoS2) as the model material.

New method turns graphene oxide into the world's strongest carbon fibers

Researchers from Penn State University and Japan's Shinshu University developed a simple and scalable process to make strong, stretchable graphene oxide fibers. Those fibers can easily be scrolled into yarns that have strengths approaching that of Kevlar.

The new GO fiber is the strongest carbon fiber ever. The researchers believe that pockets of air inside the fiber keep it from being brittle. But those fibers can also be altered to make other useful materials. For example, removing the oxygen results in a fiber with high electrical conductivity, while adding silver nanorods increases the conductivity (to the same level as copper, while being much lighter than copper).