Graphene with aroma

New production method broadens the perspectives for an improved use of the 'magic material' -- many different forms are possible

2013-10-02

(Press-News.org) This news release is available in German.

Graphene, a crystal composed of only one layer of carbon atoms arranged in a regular hexagon, is regarded as a material which is believed to be capable of performing miracles, in particular in the fields of electronics, sensor technology and display technology, but also in metrology. Only four years after the first successful preparation of graphene, its discoverers Geim and Novoselov were therefore awarded a Nobel Prize. As the original preparation method (flaking of single atomic layers of graphite) does not offer a good perspective for broad technological use, many groups of researchers are concentrating very strongly on the development of alternative manufacturing procedures. A completely new and very flexible variant has now been developed by the group of Andrey Turchanin from the University of Bielefeld in cooperation with the University of Ulm and three departments of the Physikalisch-Technische Bundesanstalt (PTB) and this has been published in the scientific journal "Advanced Materials".

In contrast to the conventional methods where graphene is manufactured, for example, by precipitation of carbon atoms from the gas phase or by thermal graphitization of silicon carbide, the scientists selected aromatic molecules as a starting point in this work. As substrates, both copper single-crystals and inexpensive polycrystalline copper foils were used. By irradiation with low-energy electrons and subsequent thermal annealing, it was then possible to convert a self-organized single-layer of the molecule biphenyl thiol, which had precipitated on the copper surface, into graphene.

To investigate the chemical and physical properties of the graphene manufactured in this way, different characterization methods from Ulm and Bielefeld universities and from PTB were applied, for example, scanning tunnelling microscopy, transmission electron microscopy, Raman spectroscopy as well as electric transport measurements at low temperatures and high magnetic fields. All these measurements confirm that graphene of excellent crystalline and electronic quality had actually been manufactured from the aromatic molecule.

The flexibility of the electron irradiation, which is possible both over large areas and also with excellent spatial resolution at small, well-defined places, now allows graphene structures of basically any form to be manufactured, e.g. quantum dots, nanoribbons or other nano-geometries with specific functionality. The selection of the temperature in the thermal conversion step also allows the degree of crystallinity and the characteristics of the graphene depending on it to be adjusted.

Additional advantages result from the versatility of the method of self-organized coating. It can be performed with different aromatic molecules which could, for example, also contain doping atoms for electronic doping of the final product. Applied in multiple layers, so-called bi-layer or multi-layer graphene could be manufactured, whose changed electronic band structure expands the potential applications of single-layer graphene. Likewise, other substrates than the copper used here (for example other metals, semiconductors, isolators) can be used. In addition, it should also be possible to manufacture graphene on any three-dimensional surfaces, as molecular self-organization also takes place on curved surfaces. The new manufacturing method broadens the perspectives for an improved use of the "magic material" in such an impressive way that the respective publication was emphasized on the cover sheet of the August issue of the scientific journal "Advanced Materials".

INFORMATION:

Contact:

Franz Josef Ahlers, PTB Department 2.6 Electric Quantum Metrology, phone +49(531) 592-2600, e-mail: franz.ahlers@ptb.de

PD Dr. Andrey Turchanin, University of Bielefeld, Faculty of Physics, Physics of Super-molecular Systems and Surfaces, Bielefeld Institute for Biophysics and Nanoscience (BINAS), Universitätsstr. 25, 33615 Bielefeld, phone: +49(521) 106-5376, e-mail: turchanin@physik.uni-bielefeld.de

Original publication:

D. G. Matei, N.-E. Weber, S. Kurasch, S. Wundrack, M. Woszczyna, M. Grothe, T. Weimann, F.-J. Ahlers, R. Stosch, U. Kaiser, A. Turchanin: Functional single-layer graphene sheets from aromatic monolayers. Advanced Materials, 25 (2013), 30, 4146-4151, dx.doi.org/10.1002/adma.201300651 [article], dx.doi.org/10.1002/adma.201370195 [frontispiece]; Wiley-VCH. ISSN 1521-4095

ELSE PRESS RELEASES FROM THIS DATE:

Early mammal varieties declined as flowering plants radiated

2013-10-02

BLOOMINGTON, Ind. -- The dramatic explosion of flowering plant species that occurred about 100 million years ago was thought to have been good news for evolving mammals, providing them with new options for food and habitat. But research by geologists at Indiana University Bloomington suggests that wasn't necessarily the case. In a study published in the journal Proceedings of the Royal Society B, David Grossnickle and P. David Polly present evidence that mammal varieties declined during the great angiosperm radiation of the mid-Cretaceous, a time when a great diversity ...

Discovery of charged droplets could lead to more efficient power plants

2013-10-02

CAMBRIDGE, Mass-- In a completely unexpected finding, MIT researchers have discovered that tiny water droplets that form on a superhydrophobic surface, and then "jump" away from that surface, carry an electric charge. The finding could lead to more efficient power plants and a new way of drawing power from the atmosphere, they say. The finding is reported in a paper in the journal Nature Communications written by MIT postdoc Nenad Miljkovic, mechanical engineering professor Evelyn Wang, and two others. Miljkovic says this was an extension of previous work by the MIT ...

Research shows genetic anti-inflammatory defect predisposes children to lymphoma

2013-10-02

(WASHINGTON, October 2, 2013) – New research shows that children with an inherited genetic defect in a critical anti-inflammatory pathway have a genetic predisposition to lymphoma. Results of the study, published online today in Blood, the Journal of the American Society of Hematology (ASH), reveal an important association between the genetic defect, which causes chronic intestinal inflammation and early onset inflammatory bowel disease, and its role in cancer development in infants and children. Among the hundreds of signaling pathways in the human immune system that ...

New method allows quantitative nanoscopic imaging through silicon

2013-10-02

A team of scientists from The University of Texas at Arlington and MIT has figured out how to quantitatively observe cellular processes taking place on so-called "lab on a chip" devices in a silicon environment. The new technology will be useful in drug development as well as disease diagnosis, researchers say. In a paper published in Nature's online journal Scientific Reports, the team said it overcame past limitations on quantitative microscopy through an opaque media by working with a new combination of near infrared light and a technique called quantitative phase ...

New imaging system can help diagnose disease, monitor hazardous substances

2013-10-02

WASHINGTON, Oct. 2, 2013—For hundreds of years, optical devices like telescopes and microscopes have relied on solid lenses that slide up and down to magnify and to focus. To tune how much light is received, conventional devices use mechanical contraptions like the blades that form the adjustable aperture in cameras. To meet demands for ever smaller imaging systems, researchers are working to create entirely unconventional ways of focusing light. In pursuit of this vision, engineers from the University of Freiburg in Germany have built a novel type of imaging system inspired ...

How one transportation business survived hurricane sandy

2013-10-02

COLUMBUS, Ohio -- In a year-long case study of a major American transportation company, researchers at The Ohio State University have uncovered the strategies that helped the company maintain safety and meet customer demand during 2012's Hurricane Sandy. One key to the company's effective response was its setup of a weather event management team, an ad hoc group that set planning priorities as the storm approached the United States, ensuring the protection of personnel and equipment in hurricane's path. More surprisingly, as landfall was imminent, the company's schedulers ...

Measuring height by connecting clocks

2013-10-02

This news release is available in German. How far above sea level is a place located? And where exactly is "sea level"? It is one objective of the geodesists to answer these questions with 1 cm accuracy. Conventional measurement procedures or GPS technologies via satellites, however, reach their limits here. Now optical atomic clocks offer a new approach, because the tick rate of a clock is influenced by gravity. This well-known, but tiny effect was measured with unprecedented precision in 2010 using two optical clocks – however, they were located at the same institute. ...

Radioactive materials and contaminants found at fracking wastewater disposal site

2013-10-02

A new study has found that liquid wastes from hydraulic fracturing, or "fracking," that was treated and released into local streams in Pennsylvania still contained elevated levels of salts and other contaminants, which could be dangerous to aquatic life and human health. The study also reports high levels of radioactive materials in stream sediments at the disposal site. Published in the ACS journal Environmental Science & Technology, it states that the scientists recommend use of advanced treatment technologies to further remove the potentially harmful material. Avner ...

Toward understanding the dangers of the fake marijuana called 'Spice' or 'K2'

2013-10-02

The harmful effects of increasingly popular designer cannabis products called "Spice" or "K2" have puzzled scientists for years, but now a group of researchers is reporting progress toward understanding what makes them so toxic. The study, published in the ACS journal Analytical Chemistry, describes development of a method that could someday help physicians diagnose and treat the thousands of young adults and teens who end up in emergency rooms after taking the drugs. Jeffery Moran and colleagues note that synthetic marijuana, often marketed as "natural incense," "potpourri," ...

Recruiting E. coli to combat hard-to-treat bacterial infections

2013-10-02

The notorious bacteria E. coli is best known for making people sick, but scientists have reprogrammed the microbe — which also comes in harmless varieties — to make it seek out and fight other disease-causing pathogens. The researchers' report appears in the journal ACS Synthetic Biology and describes development of this new type of E. coli that can even kill off slimy groups of bacteria called biofilms that are responsible for many hard-to-treat infections, such as those that take hold in the lungs, the bladder and on implanted medical devices. Matthew Wook Chang and ...

Prioritise vaccine boosters for vulnerable immunocompromised patients and prevent emergence of new COVID variants, say scientists

[Press-News.org] Graphene with aroma
New production method broadens the perspectives for an improved use of the 'magic material' -- many different forms are possible

Graphene with aroma

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: