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EXPLAIN IT WITH MOLECULES-- WHAT IS THE STRUCTURE OF GRAPHENE?
 


Graphene is a one-atom-thick planar sheet of sp2-bonded carbon atoms. The arrangement forms a densely packed honeycomb that can be visualized as an atomic-scale chicken wire made of carbon atoms and their bonds. The carbon-carbon bond length in graphene is about 1.42 Ĺ (angstroms) which compares to a bond length of 1.50 Ĺ for C-C single bond as found in the ethane molecule. (Note: The angstrom (Ĺ) is an internationally recognized unit of length equal to 0.1 nanometre or 1 × 10 -10 meters.

Graphene is the basic structural element of some carbon allotropes including graphite, carbon nanotubes, and fullerenes. The Nobel Prize in Physics for 2010 was awarded to Andre Geim and Konstantin Novoselov "for groundbreaking experiments regarding the two-dimensional material graphene".

Graphene structure shown using Jsmol -The Graphene Molecule shown above was created using ArgusLab

Note about 3D molecules -- Our files on this page now use Jsmol instead of Jmol. These files make use of Javascript which permits viewing of molecules on tablets, phones and easier use on Macs. For the graphene_jmol file. -- Jsmol is best viewed with the Chrome browser.

Rotate the Graphene molecule

(Hold the left mouse button down over the image and move the mouse to rotate the graphene molecule -- you can easily see that graphene is only ONE molecule thick).

Notice that each carbon atom is the same distance to each of its neighboring carbon atom.

What is the bond length for a Carbon-Carbon bond in Graphene Molecule?

Click right mouse button-->Style -->Scheme--> Ball and Stick

Double click left mouse bottom on any carbon atom, then drag + to nearby carbon atom and double click again to get distance.

View other 3-D allotropes of Carbon:

Graphite molecule
Diamond molecule
Fullerene
Carbon Nanotube

 

 

Potential applications

New Materials

As of 2009, graphene appears to be one of the strongest materials ever tested. Measurements have shown that graphene has a breaking strength 200 times greater than steel.[1]

Graphene transistors

In 2008 Dr Kostya Novoselov and Professor Andre Geim from The School of Physics and Astronomy at The University of Manchester reported in the journal Science that graphene can be carved into tiny electronic circuits with individual transistors having a size not much larger than that of a molecule. [2]

Single molecule gas detection --Graphene makes an excellent sensor due to its 2D structure. The fact that its entire volume is exposed to its surrounding makes it very efficient to detect adsorbed molecules. Researchers at the University of Manchester --Centre for Mesoscience and Nanotechnology-- have used the world's thinnest material to create sensors that can detect just a single molecule of a toxic gas. [3] The operational principle of such sensors is based on changes in electrical conductance of a number of base materials when gas molecules are adsorbed on their surface. The existing sensors can detect gases in concentrations as small as 1 part per million or less.

Integrated circuits --The unique properties of thin layers of graphite make the material attractive for a wide range of potential electronic devices. Researchers have experimentally demonstrated the potential to replace copper for interconnects in future generations of integrated circuits. Because graphene can be patterned using conventional microelectronics processes, the transition from copper could be made without integrating a new manufacturing technique into circuit fabrication.

Graphene biodevices -Graphene's modifiable chemistry, large surface area, atomic thickness and molecularly-gatable structure make them excellent candidates for mammalian and microbial detection and diagnosis devices [5]

One of the most ambitious biological application of graphene is for rapid, inexpensive DNA sequencing. [6]

References and Readings

1 Lee, C. et al. (2008). "Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene". Science 321 (5887): 385. doi:10.1126/science.1157996.Abstract: http://www.sciencemag.org/cgi/content/abstract/321/5887/385.

2 L. A. Ponomarenko, F. Schedin,1 M. I. Katsnelson, R. Yang, E. W. Hill, K. S. Novoselov,A. K. Geim "Chaotic Dirac Billiard in Graphene Quantum Dots" Science 18 April 2008: Vol. 320. no. 5874, pp. 356 - 358. Abstract: http://www.sciencemag.org/cgi/content/abstract/320/5874/356

3 Schedin, F. et al. (2007). "Detection of individual gas molecules adsorbed on graphene". Nature Mater 6 (9): 652–655. Abstract: http://www.nature.com/nmat/journal/v6/n9/full/nmat1967.html

4 Murali, R. Brenner, K. Yang, Y. Beck, T. Meindl, J. D. Resistivity of Graphene Nanoribbon Interconnects. Electron Device Letters, IEEE, June 2009 Volume: 30, Issue: 6: 611-613 Abstract: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4968006

5 Mohanty, Nihar; Vikas Berry (2008). "Graphene-based Single-Bacterium Resolution Biodevice and DNA-Transistor— Interfacing Graphene-Derivatives with Nano and Micro Scale Biocomponents". Nano Letters 8: 4469–76. Abstract: http://pubs.acs.org/doi/abs/10.1021/nl802412n

6 Xu, M. S. Xu; D. Fujita and N. Hanagata (2009). "Perspectives and Challenges of Emerging Single-Molecule DNA Sequencing Technologies". Small 5 (23): 2638–49. Abstract: http://www.ncbi.nlm.nih.gov/pubmed/19904762

Carbon Activities
Carbon Home Page
Carbon Molecule
Carbon 3-D
Chime Tutorial
Graphene Molecule
More on Carbon Fullerenes
Simple Carbon Compounds
Carbon *.pdb Files
Carbon atoms in methane
Diamond -- Carbon
Graphite -- Carbon
graphene vs. carbyne
carbyne 3-D

 


 

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