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Researchers Submit Patent Application, "Crystalline Graphene and Method of Making Crystalline Graphene", for Approval

July 31, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Hosmane, Narayan S. (Dekalb, IL); Chakrabarti, Amartya (Hoffman Estates, IL), filed on December 6, 2011, was made available online on July 17, 2014.

The patent's assignee is Board of Trustees of Northern Illinois University.

News editors obtained the following quote from the background information supplied by the inventors: "Within the last few years, graphene has received special attention from the scientific world due to its unique mechanical, and electrical properties..sup.1-3 The widespread application of graphene is not just limited to the fields of sensors.sup.4-6 nanoelectronics.sup.6 composites.sup.7-8 hydrogen storage.sup.9 lithium-ion batteries.sup.10 but also shown promises in medicine as antibacterial materials..sup.11 The diversity of the technological applications of graphene materials drives the search for facile routes to produce graphenes in high yields. Recent research for synthesis of such materials involved either chemical or electrochemical reduction of exfoliated graphite oxide..sup.12,13 Most of these techniques require use of strong oxidizing agents, for example, H.sub.2SO.sub.4/KMnO.sub.4. A recent report described the production of graphene via reduction of CO using Al.sub.2S.sub.3..sup.14 Nonetheless, a well-controlled large scale production protocol for graphene structures is still in a great demand.

"Another disadvantage of syntheses of graphene is that the product produced is of low crystallinity. Most syntheses of graphene begin with graphite, then exfoliate the graphite by oxidation to graphite oxide, followed by reduction..sup.24 These 'top-down' processes introduce extensive defects into each layer of graphene. A 'bottom-up' synthesis of few-layer graphene also produced graphene showing poor crystallinity, as indicated by broad lines in the X-ray diffraction pattern..sup.25"

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "In a first aspect, the present invention is a method of producing graphene, comprising forming a composition comprising magnesium and carbon, and isolating graphene from the composition.

"In a second aspect, the present invention is a method of producing isolated graphene, comprising isolating graphene from a composition comprising graphene and magnesium.

"In a third aspect, the present invention is isolated crystalline graphene.

"In a fourth aspect, the present invention is a method of forming a graphene ink, comprising dispersing or suspending the isolated crystalline graphene into a liquid.

"In a fifth aspect, the present invention is a graphene ink comprising crystalline graphene and a liquid.

"In a sixth aspect, the present invention is a method of preparing an electronic device, comprising preparing the electronic device from the isolated crystalline graphene.

"In a seventh aspect, the present invention is an electronic device, comprising the isolated crystalline graphene.

"Definitions

"The term 'graphene' includes single-layer graphene and few-layer graphene. The term 'few-layer' graphene includes graphene have 2-10 layers, preferably 3-7 layers. The term 'graphene nanosheets' refers to graphene particles or crystallites having individual widths and lengths of at most 999 nm, more preferably at most 500 nm, most preferably at most 300 nm, including 450, 400, 350, 300, 250, 200, 150, 100 and 50 nm.

"The terms 'crystalline graphene' and 'crystalline few-layer graphene' refers to graphene and few-layer graphene, respectively, which has an X-ray diffraction pattern under Cu.sub.K.alpha. radiation having a (100) peak with a full-width at half-maximum intensity which is at most 200% of the full-width at half-maximum intensity of the (100) peak illustrated in FIG. 7, more preferably at most 150% of the full-width at half-maximum intensity of the (100) peak illustrated in FIG. 7, most preferably 125% of the full-width at half-maximum intensity of the (100) peak illustrated in FIG. 7, including 130%, 125%, 120%, 115%, 110%, 105% and 100%. The graphene described in Herron et al. (ref. 25) is not crystalline graphene.

"The term 'isolated' means substantially freed from impurities, by-products and contaminants; the term 'isolating' means to substantially free from impurities, by-products and contaminants.

"The term 'particle size' means the average diameter of the image of the particle as viewed by electron microscopy, unless otherwise slated. The term 'average particle size' means the average of the particle sizes of a collection of particles.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1. Dry ice chamber with holes at both ends.

"FIG. 2. Quartz-Glass Reaction Chamber for Ignition of Mg Spirals.

"FIG. 3. Isolation of Graphene Using AAO Template.

"FIG. 4. 633 nm Raman Spectrum of the carbon species exhibiting the G'-band at 2645 cm.sup.-1, G-band at 1570 cm.sup.-1 and a D-band at 1325 cm.sup.-1. Inset: the expanded view of the G'-band showing the splitting pattern of the peak.

"FIG. 5. TEM images of few-layer graphene. (a) Graphenes with an average length of 50-100 nm. (b) Crystalline graphenes with an average length of 200 nm.

"FIG. 6. High resolution TEM image of few-layer graphene exhibiting the number of layers to be between three and seven.

"FIG. 7. XRD pattern of the carbon species.

"FIG. 8. EDX spectra of the graphene nanosheets, C 90.32 (Atm. Wt. %); Mg 2.38 (Atm. Wt. %); 0 7.30 (Atm. Wt. %)."

For additional information on this patent application, see: Hosmane, Narayan S.; Chakrabarti, Amartya. Crystalline Graphene and Method of Making Crystalline Graphene. Filed December 6, 2011 and posted July 17, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=2611&p=53&f=G&l=50&d=PG01&S1=20140710.PD.&OS=PD/20140710&RS=PD/20140710

Keywords for this news article include: Board of Trustees of Northern Illinois University, Carbon, Emerging Technologies, Graphite, Minerals, Nanosheets, Nanotechnology.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Politics & Government Week


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