Exfoliation - Page 2

Graphene platform, Cambridge Graphene Platform (CGP) and Nissha Printing will co-develop new electronic devices based on CGP s graphene ink technology. This alliance is expected to last three years.

Nissha will contribute its own printing technology to help develop CGP's inks. The company hopes to apply those new inks in the field of printed electronics. CGP and Graphene Platform will develop the inks themselves (graphene inks and other nanomaterials too) and will provide advice and consulting to Nissha.

Turkey's Grafen reports first results from their graphene liquid-phased exfoliation research (conducted with help from Ukraine's National Academy of Sciences - BPCI). The new method uses direct liquid-phase exfoliation of graphite to create graphene sheets and it creates unique product crystallinity and lower environmental footprint.

Grafen reports that initial atomic force microscopy (AFM) data shows multilayered graphene sheets, 10-15 nm in thickness and about 0.5 um in diameter proving great potential of the process. Hopefully we'll hear more from Grafen about this new process and more results soon.

Researchers from Sweden demonstrated a simple and mature technology for inkjet printing of high quality few-layer graphene.

The researchers exfoliate graphene from graphite flakes in dimethylformamide (DMF), and then DMF is exchanged by terpineol through distillation (there is a large difference between DMF's and terpineol's boiling points). Terpineol is of much lower volume than DMF and so the graphene is significantly concentrated. Terpineol is also non-toxic and features high-viscosity.

The UK Technology Strategy Board launched a new collaborative R&D project called NanoSynth with a budget of almost a million GBP ($1.5 million USD) - to develop a synthesis platform for the industry-scale production of graphene-filled epoxy resins for advanced composite applications.

According to the NetComposites, the project coordinator, those graphene epoxy resins will improve current resins and will feature better strength, stiffness, toughness, electrical conductivity and thermal performance. The new resins may prove to have a significant impact on a wide range of markets, including the aerospace and automotive ones. The worldwide yearly market of epoxy resins is estimated at over $15 billion.

Researchers from the University of Alberta developed a new low-cost process to turn hemp bast fibers into graphene-like materials that can be used in energy storage electronics.

They use a part of the hemp plant called the bast, which is usually thrown away during industrial hemp production - it's a waste product. It is a nanocomposite made up of layers of lignin, hemicellulose, and crystalline cellulose. If you process it the right way, it separates into sheets similar to graphene.

Researchers from Australia discovered that molybdenum oxides can be used to improve graphene’s charge-carrying capabilities. This can results in devices that are smaller and/or enable faster data transfer.

The researchers created new sheets of this hybrid material using exfoliation. Those sheets are 11 nanometers thick and can be turned into a semiconductor (to fabricate transistors for example). The final device features an electron mobility greater than 1,100 cm²/Vs - higher than the current standard for low dimensional silicon.

The European NanoMaster project (a EC Seventh Framework funded project which started on December 2011 and is being led by NetComposites, UK, and involves 12 other project partners including Philips) has developed new grades of expanded graphite - used to produce high-quality graphene. The project aims to develop up-scale processing methods for production of graphene and expanded graphite reinforced thermoplastic masterbatches and compounds.

The new expanded graphite and nano-graphite materials are designed to be easier to exfoliate in both chemical and mechanical processes and are also useful when trying to tailor the properties of the final composite for different applications. As part of the project, high quality graphene has been produced from those new graphite materials via a multiple-stage chemical exfoliation process involving oxidative treatment, washing, filtration and reduction.

Angstron Materials have been awarded a new patent (US #8,114,373) for its next-step method that effectively exfoliates layered graphene and offers several key advantages. Using this method one can produce nano graphene platelets (NGPs) with a thickness thinner than 100nm and in many cases thinner than 10 nm or as thin as 0.34 nm to 1.02 nm.

Angstron's process does not use undesirable chemicals, time-intensive wash steps or require high exfoliation temperatures. In addition, the method does not produce contaminated waste water and its associated disposal costs.

This is a guest post by Thanasis Georgiou, the Director of MoS2 Crystals, a Manchester based MoS2 Crystals and flakes provider.

Graphene has mesmerized the labs of hundreds of research groups worldwide. With its exceptional set of properties it is widely expected that it would find applications in a variety of areas. However, looking back on the work of the Nobel Laureates, their highly cited PNAS publication was entitled Two-dimensional atomic crystals(Novoselov et al., 2005). Indeed, graphene was just the first of many different crystalline materials that can be exfoliated and investigated. Graphene justifiably attracted such intense research due to its exotic Dirac-cone nature of its electronic spectrum.

Nobel Prize-winner (together with Andre Geim) Professor and Kostya Novoselov Professor Volodya Falko from Lancaster University have released a graphene roadmap. The roadmap discusses the different possible applications for graphene and also the different ways to produce the material.

The authors says that the first key application is conductors for touch-screen displays (replacing ITO), where they expect can be commercialized within 3-5 years. They also see rollable e-paper displays soon - prototypes could appear in 2015. Come 2020, we can expect graphene-based devices such as photo-detectors, wireless communications and THz generators. Replacing silicon and delivering anti-cancer drugs are interesting applications too - but these will only be possible at around 2030.