Le graphène ouvre la voie à un laser impossible auparavant. Les électrons au sein de la couche de graphèneDes chercheurs du centre de recherche allemand Helmholtz-Zentrum Dresden-Rossendorf ont montré dans la revue Nature Physics que les propriétés du graphène dans un champ magnétique ouvraient la voie à la création d’un laser unique en son genre. Les travaux ont été menés en partenariat avec le Laboratoire National des Champs Magnétiques Intenses de Grenoble, entre autres. Lorsqu’ils ont exposé une couche de graphène à un champ magnétique de quatre Tesla, soit un champ quarante fois plus important qu’un aimant fer à cheval, les scientifiques ont remarqué que les électrons traversant le graphène occupaient seulement certains états et lorsqu’ils ont utilisé un laser à électrons libres pour examiner ces états, ils se sont rendu compte que les électrons prenaient à leur tour des états bien précis.
Cela signifie qu’en changeant le champ magnétique, il est possible de changer la façon dont les électrons traversent le graphène. Blackest is the new black: Scientists have developed a material so dark that you can't see it... - Science - News. Puritans, Goths, avant-garde artists, hell-raising poets and fashion icon Coco Chanel all saw something special in it. Now black, that most enigmatic of colours, has become even darker and more mysterious. A British company has produced a "strange, alien" material so black that it absorbs all but 0.035 per cent of visual light, setting a new world record. To stare at the "super black" coating made of carbon nanotubes – each 10,000 times thinner than a human hair – is an odd experience.
It is so dark that the human eye cannot understand what it is seeing. Shapes and contours are lost, leaving nothing but an apparent abyss. If it was used to make one of Chanel's little black dresses, the wearer's head and limbs might appear to float incorporeally around a dress-shaped hole. Actual applications are more serious, enabling astronomical cameras, telescopes and infrared scanning systems to function more effectively. A sample of the new material.
"You would lose all features of the dress. News Archives • Graphene Tracker. Graphenea names Grafen Co. as the Middle East distributor By Marko Spasenovic on April 21, 2014 Grafen Co. and Graphenea S.A. have entered into an agreement for the distribution of Graphenea’s products in Turkey and Middle Eastern Countries. The product line includes all CVD based graphene sheets, graphene oxide dispersions, reduced graphene oxide powders and related services.
“We look forward to servicing the Middle Eastern region with the Graphenea product line”, […] Click for more… planarTECH licenses MoS2 process from Columbia University & delivers first MoS2-capable CVD system to the University of Oxford By Marko Spasenovic on April 14, 2014 planarTECH announced that it has licensed an a process for production of MoS2 from Columbia University, and delivered its first MoS2-capable CVD system to the University of Oxford. planarTECH has recently branched out into process and equipment for other 2D materials that are complementary to its activities in the graphene market. Click for more… Graphene-based mesh to stop bleeding and disinfect wounds - Graphene Tracker. 32 Flares Filament.io 32 Flares × DETROIT, May 10, 2013 (GLOBE NEWSWIRE) — Nano Labs Corp. (OTCQB:CTLE) is pleased to announce today it has developed an innovative hemostatic material which it has filed for provisional patent and is currently presenting to the biomedical industry.
The new innovation includes a nano biotechnology hemostatic mesh, which creates a mechanical barrier stopping blood flow in wounds and integrates both physical and chemical protection, and antibacterial properties. The proprietary nano material is made with polyvinyl nanofibers, graphene oxide sheets and plate nanoparticles which combine to produce a water-soluble synthetic polymer which has excellent film forming quality, a high tensile strength and flexibility, and allows for emulsifying of additional biomedical enhancing materials that would otherwise not be able to be blended together. “There have been a number of patented hemostatic materials that are based on the use of nanofibers. Source: Nano Labs. [1106.4460] Total light absorption in graphene. Layer-by-Layer Assembly of Ultrathin Composite Films from Micron-Sized Graphite Oxide Sheets and Polycations - Chemistry of Materials.
Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 31, Pr. Nauky, 252022 Kyiv, Ukraine; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802; Metal−Polymer Research Institute, 32A Kirov Street, Gomel, 246652, Belarus; and National T. Shevchenko University, 64, Vladimirskaya Str., 252033 Kyiv, Ukraine Chem. Mater. , 1999 , 11 (3), pp 771–778 DOI: 10.1021/cm981085u Publication Date (Web): January 28, 1999 Copyright © 1999 American Chemical Society Section: Abstract Unilamellar colloids of graphite oxide (GO) were prepared from natural graphite and were grown as monolayer and multilayer thin films on cationic surfaces by electrostatic self-assembly. Citing Articles View all 241 citing articles Citation data is made available by participants in CrossRef's Cited-by Linking service.
This article has been cited by 145 ACS Journal articles (5 most recent appear below). Ideas on RepRap Printing Graphene - RepRapPro. A recent paper on laying down graphene for making capacitors by El Cady et al. is very interesting. They coated DVD-sized discs with a colloid of graphene oxide (GO). They then used a LightScribe DVD writer (the type that lets you create your own labels on a photo-sensitised DVD) to zap the GO with the writer's 780nm infrared laser. This converted the GO to conducting graphene. You can make your own GO (the recipie is here ), or you can buy it online ( for example here ). And it should be straightforward to form a sol/colloid of it using sonication (possibly in an ultrasonic cleaner like this one ).
It could then be deposited on conventionally reprapped 3D prints from a specially designed head (for example like this single-drop inkjet or this one ) then zapped with an IR laser on the head like this one to convert the GO to graphene. Our researches continue... New Form of Carbon Synthesized: Grossly Warped 'Nanographene' Chemists at Boston College and Nagoya University have together synthesized the first example of a new form of carbon, the team reports in the most recent edition of the journal Nature Chemistry. This new material consists of many identical piece of grossly warped graphene, each containing exactly 80 carbon atoms joined together in a network of 26 rings, with 30 hydrogen atoms decorating the rim. These individual molecules, because they measure somewhat more than a nanometer across, are referred to generically as “nanocarbons,” or more specifically in this case as “grossly warped nanographenes.” Until recently, scientist had identified only two forms of pure carbon, namely: diamonds and graphite.
Then in 1985, chemists were stunned by the discovery that carbon atoms could also join together to form hollow balls, known as fullerenes. Graphene has been highly touted as a revolutionary material for nanoscale electronics. Graphene Enables Femtosecond Range Response Rates in Optoelectronic Components. First Posted: Jul 15, 2013 06:38 PM EDT The use of graphene in telecommunications could dramatically accelerate internet speeds by up to a hundred times, according to new research. Like Us on Facebook In a paper published in Physical Review Letters, researchers from the Centre for Graphene Science at the Universities of Bath and Exeter have demonstrated for the first time incredibly short optical response rates using graphene, which could pave the way for a revolution in telecommunications.
Every day large amounts of information is transmitted and processed through optoelectronic devices such as optical fibres, photodetectors and lasers. Ordinarily optical switches respond at rate of a few picoseconds – around a trillionth of a second. (Photo : Mitchell Ong, Stanford School ) Graphene is just one atom thick, but remarkably strong. In the long term this research could also lead to the development of quantum cascade lasers based on graphene. La pile du futur est née, ultra-puissante et biodégradable. Charger un téléphone en 30 secondes, une voiture électrique en l’espace de quelques minutes, c’est pour bientôt ! Deux scientifiques de l’université de Californie à Los Angeles ont créé par hasard une pile super-puissante et biodégradable lors de leurs travaux sur le graphène, rapporte le site Co.Design.
Les résultats de leur recherche ont été publiés dans la revue Nature. Le graphène est un matériau révolutionnaire découvert en 2004 qui a permis à ses inventeurs de remporter le Nobel de physique en 2010. Composé d’atomes de carbone, il est transparent, très résistant, et pour l’instant le meilleur conducteur électrique connu à ce jour. C’est en cherchant une manière plus pratique de fabriquer du graphène que Richard Kaner et Maher El-Kady ont mis au point le «super-condensateur»: une nouvelle pile flexible, superpuissante et biodégradable qui pourrait bien être la potentielle alimentation des gadgets ou systèmes électroniques de nouvelle génération. Like this: J'aime chargement… La pile du futur est née, ultra-puissante et biodégradable.