Monthly Archives: July 2011
Graphene, the strongest material on earth, now produced from cookies, roaches and dog feces
Graphene is a material made of carbon. It is a particularly interesting material because in graphene, carbon manages to arrange itself in a sheet just one atom thick (see pic on the left). The material is so thin, that three million sheets of graphene on top of each other would be just 1mm thick. This one-atom thick sheet, densely packed in a honeycomb lattice, has excellent electrical, mechanical and thermal properties that make it the strongest material on earth, an improvement upon and a possible replacement for silicon, and the most conductive material known to man.
In 2004, physicists at the University of Manchester and the Institute for Microelectronics Technology, Chernogolovka, Russia, first isolated individual graphene planes by exfoliating graphite (i.e. the material used for pencils) using adhesive tape. Since 2009 it has been described as the strongest material on earth, 200 times stronger than steel. In 2010, the Nobel Prize in Physics was awarded to Andre Geim and Konstantin Novoselov, “for groundbreaking experiments regarding the two-dimensional material graphene”.
It would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap.
said Professor James Hone of Columbia University in a statement.
As for uses? It can be used for making up new materials and electronic devices. Sort of like plastics are used nowadays but with an extra touch of technology. It could be used for transparent electronics that are stronger, cheaper, and more flexible such as shown on the right. Professor Tour of Rice University said teasingly:
You could theoretically roll up your iPhone and stick it behind your ear like a pencil.
Graphene is usually made up from graphite. But as the demand for cheap and fast large-scale graphene production becomes imminent, it quickly became clear that making graphene by splitting graphite crystals using adhesive tape, had no future.
Now a team of researchers led by Prof Tour, managed at to grow graphene directly on the backside of a copper foil at 1050°C, using six easily obtained, low or negatively valued raw carbon-containing materials used without pre-purification (cookies, chocolate, grass, plastics, roaches, and dog feces). Read the full paper here. Thanks to Anastassia for the story!
Worst comes to worst you just might end up using up that pizza from last night to get a new rollable iPhone. And think twice before you scold your dog again for doing a #2 on the carpet!
Chemistry never sounded this good!
I just heard from a professor friend at UCLA about a fabulous approach to teaching by her colleague, organic chemistry Professor Neil Garg. According to a UCLA press release:
Undergraduates in Neil Garg’s organic chemistry course produce clever, creative music videos as an extra-credit assignment. The bigger secret may be just how much chemistry they learn by doing so, as none of them are chemistry majors and most admit they didn’t like chemistry when the class started.
Basically, students are asked to produce a music video with a theme from organic chemistry. Sounds geeky? Ha. You will be amazed by how cool it is:
SN2 electrophiles: primary carbon not tertiaryLone pairs show nucleophilicityUse polar aprotic solventTosylates and halides, they will leaveInversion of stereochemistry
So students are able to learn chemistry in a fun way. You can read the full article and get some more videos here and in Garg’s website, including a Lady Gaga-ish gig called “Bond this way“.
Why is the sky blue?
A question that I get very often is why did I ever return to Greece to do science. It is indeed hard to explain why would a young scientist leave an educational and technological paradise such as Yale University to seek a better future in a country on the verge of default. So, I usually start by explaining the ties to my family, my friends, the ease to speak my own language, etc. But then again only one picture could actually summarize it 🙂
In a country with such blue skies, I often get bombarded with questions from my non-scientist friends such as: “Why is the sky blue? Why is the sunset red?”. So here it is in very simple words:
Light looks white, but it is actually a combination of colors (you’ve all see a rainbow right?). These colors are in order: red, orange, yellow, green, blue, indigo and violet. These colors all have different energies, violet has the highest energy and red the lowest. Light travels in a straight line when it is undisturbed, such as in space. What happens when light enters the atmosphere?
Atmoshpere – Blue Sky
The atmosphere is composed by particles such as dust and water that can be seen with the naked eye, but also smaller particles such as oxygen and nitrogen that are so small that we cannot see them. When light enters the atmosphere it hits these small molecules such as oxygen (21%) and nitrogen (78%) (gases). Gases then tend to absorb not all of the light but only part of it. By “part of the light” I mean that they absorb only one out of 7 colors. It so happens that this color is blue. After a while, the gas molecules give off this blue light in all different directions in the atmosphere. The blue light is scattered everywhere you look in the atmosphere. This is why the sky is blue. This is also why the sun looks yellow (remember light is white). Because if you take off blue from the rainbow, all the remaining colors together look yellow.
Atmosphere – Red Sunset
So why isn’t the sky blue also at sunset? At sunset, the sun is close to the horizon and light needs to pass through a much longer path through the atmosphere to reach you than at noon. Close to the horizon different particles (such as aerosols) are concentrated. It so happens that these aerosols absorb the red light instead of the blue for a while and then give off this red light at all possible directions such as oxygen and nitrogen did for the blue light. Therefore we can enjoy red sunsets and blue skies…
To leave or not to leave?
A few days ago, I was part of a very interesting debate organized by “Intelligence Squared Greece“. The question was: should young Greeks, who pursue professional and intellectual advancement as well as better quality of life, stay in Greece and persevere through the financial crisis (and whatever it brings about) or leave and seek a better future outside their homeland? http://www.intelligencesquared.com/greece/events/2011/spring/brain-drain
Three panelists defended the proposal to leave the country and three more advocated for staying. You can find the full debate here. One of the panelists was a Greek computer scientist from Berkeley, who (obviously) spoke for leaving the country and seeking the scientific and technological scene somewhere else. I could sense a tinge of bitterness in his voice as he mentioned that he had also taught at the Greek University, but felt that the lack of meritocracy and organization pushed him out of the country. Let’s face it, Greece is still very far behind in whatever has the words “research” and “development” in a sentence. However, as the speaker continued with his thesis, I could feel his nostalgia for the motherland and that he still has not given up on Greece. He mentioned that China is becoming a superpower because it invested in bringing back the Chinese scientists from abroad and spending huge amounts in R&D and building university and technological infrastructure. Greece has the opportunity to advance through the crisis and the answer is hidden in research, development, and education.
As for me? I have no doubts that coming back to Greece was the best decision. For me opportunities might be less prominent within a crisis, but they may also have the biggest reward. Moreover, the scientific future of Greece will be determined by the scientists who stayed an the ones who returned (or continue to return), not the ones who left.
Thank you, Intelligence Squared Greece, for providing the grounds for such interesting contemplations!
10 years in science – was it worth it?
It was a blast!! (and still is…:)) People who love science know that the joy behind any, even an infinitesimal scientific discovery is enormous – and there is little out there to compete with that feeling. Science has given me the opportunity to work in three different countries (Greece, Germany, and the US) and to meet so many important and different people and cultures. But most importantly, it has given me the opportunity to add my very own small contribution to making this world better, not only with new scientific discoveries but also by teaching the love to science to aspiring scientists.
Going back to Heidelberg for the 625th anniversary of the University I was proud to see my profile put up as part of the celebrations. An English version is coming up soon…