. | . |
Graphene is 3D as well as 2D by Staff Writers London, UK (SPX) Sep 24, 2019
Graphene is actually a 3D material as well as a 2D material, according to a new study from Queen Mary University of London. Realising that it is a 3D material is important for understanding its mechanical properties and for developing novel graphene-based devices. Often hailed as a 'wonder material', graphene has the highest known thermal and electrical conductivity, is stronger than steel, light, flexible and transparent. Its uses are wide-ranging and recently it has been shown it could even act as a barrier against mosquito bites. In this study, published in the journal Physical Review Letters, the researchers asked two fundamental questions: to what extent is graphene graphite, and what is the true thickness of graphene? To their surprise, they found that 2D graphene, which is a flat single layer of carbon atoms arranged in a honeycomb structure, has many of the same mechanical properties as 3D graphite, which is a naturally occurring form of carbon made up from a very weak stack of many layers of graphene. They show that graphene shares a similar resistance to compression as graphite and that it is significantly thicker than is widely believed. If the thickness of a block of graphite 100 layers thick is measured, the thickness of a single graphene layer is simply the thickness of the graphene block divided by 100. Therefore, it is reasonable to consider the thickness of graphene as 0.34 nm. Dr Yiwei Sun, lead author of the study from Queen Mary University of London, said: "Graphene owes its thickness to an array of chemical bonds sticking out above and below the 2D plane of carbon atoms. Hence graphene is really a 3D material, albeit with a very small thickness. "By applying conventional 3D theory, which has been used for around 400 years, to 2D materials such as graphene, which have been known for 15 years, we show that similar arguments apply to other so-called 2D materials, such as boron nitride and molybdenum disulphide. In that sense, 2D materials are actually all 3D." Graphene is often called the world's first two-dimensional material. It was discovered in 2004 by peeling off graphene flakes from bulk graphite (used in pencil leads and lubricants) using sticky tape. It is regarded as part of a new class of 2D materials and it is currently modelled by scientists as a sheet of atoms with very little depth, hence the name 2D material.
Research Report: '3D strain in 2D materials: to what extent is monolayer graphene graphite?'
Scientists predict new forms of superhard carbon Buffalo NY (SPX) Sep 12, 2019 Superhard materials can slice, drill and polish other objects. They also hold potential for creating scratch-resistant coatings that could help keep expensive equipment safe from damage. Now, science is opening the door to the development of new materials with these seductive qualities. Researchers have used computational techniques to identify 43 previously unknown forms of carbon that are thought to be stable and superhard - including several predicted to be slightly harder than or nearly ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |