GRAFENSKA UČIONICA
Priča o grafenu počinje 2004. godine kada su ga Konstantin Novoselov i Andre Gejm, ruski fizičari na Univerzitetu u Mančesteru, u Velikoj Britaniji izdvojili iz parčeta grafita. Grafen je jednomolekulski sloj grafita i dvodimenzionalna mreža ugljenikovih atoma u strukturi pčelinjeg saća. Za izdvajanje, koristili su lepljivu traku i tako prvi put dobili minijaturne flekice tog materijala. Grafit debljine jednog milimetra sadrži tri miliona slojeva grafena. Na sobnoj temeperaturi elektroni u grafenu su vrlo mobilni i pokazuju svojstvo balističkog transporta na mikrometarskim udanjenostima. Ta svojstva daju osnovu za buduću grafensku elektroniku, s mogućim ogromnim pozitivnim uticajem na tehnologiju. Grafen je skoro u potpunosti providan, ali istovremene i toliko gust da ni najmanji atomi gasa ne mogu da prođu kroz njega. Elektricitet provodi jednako dobro kao i bakar. Sto puta je jači od čelika a može se rastegnuti i do 20 %.Istovremeno i najjači i najtanji materijal poznat svetu, grafen nalazi primenu u brojnim oblastima, od kvantne fizike do elektronike. Podesan je za izradu ekrana osetljivih na dodir, svetlosnih panela i solarnih ćelija. Kada bi se pomešao sa plastikom, omogućio bi izradu materijala za sledeću generaciju aviona, satelita i automobila. Grafen je u stanju da od slane vode pravi vodu za piće. Naučnici veruju da bi, ukoliko se slana voda propusti kroz sićušne pore ovog materijala, molekuli tečnosti prošli, dok bi se so na njemu zadržavala kao na rešetki. Trenutno je grafen ipak daleko od primene i postoji nekoliko velikih prepreka koje treba prevladati pre pojave u komercijalnim uređajima. Na prvom mestu postoji nerešen problem pouzdane proizvodnje grafena. Poznati postupci, poput mehaničke eksfoliacije iz grafita, daju uzorke čiju veličinu i kvalitet nije moguće predvideti. Jedan od ciljeva u trenutnim istraživanjima je kontrolisanje krojenje elektronskih osobina grafena, posebno otvaranjem energijskog procepa na Fermijevom nivou. Pretpostavlja se da bi zbog svoje specifične strukture mogao da zameni silikonske čipove koji se koriste za funkcionisanje skoro svih elektronskih uređaja , posebno za izradu računara.
Vrhunski teniseri, Novak Đoković i Endi Mari koriste rekete izrađene od ovog materijala.



GRAPHENE CLASSROOM

The story about graphene started in 2004, when Konstantin Novoselov and Andre Geim, Russian physicists at the University of Manchester, Great Britain, isolated it from a larger part of graphite. Graphene is an allotrope of carbon, atomic scale graphite layer in the form of a two-dimensional hexagonal lattice in which one atom forms each vertex. To isolate it, the scientists used duct tape and thus obtained miniature particles of the material for the first time. One millimetre “thick” graphite contains three million layers of graphene. At room temperature, electrons in graphene are very mobile and they show properties of ballistic transport at micrometer distances. These properties are the base of future graphene electronics, with possible tremendous positive influence on technology. Graphene is almost completely transparent, but at the same time so dense that even the smallest atoms of gas cannot penetrate it. It can conduct electricity equally well as copper. It is one hundred times stronger than steel, and it can be stretched up to 20%. Being both the strongest and the thinnest material known to the world, graphene can be applied in many fields, from quantum physics to electronics. It is suitable for production of touch screens, light panels and solar cells. If we mixed it with plastic, it would enable the production of material for the next generation of aircraft, satellites and automobiles. Graphene can be used in production of drinking water out of salty water. Scientists believe that, if we filter salty water through minute pores of this material, molecules of liquid would pass, while salt would stay as if it were kept by the grid. Nowadays graphene is still far from its application and there are several major obstacles to pass before its appearance in commercial devices. Firstly, there is an unsolved problem of the reliable production of graphene. Known procedures, such as mechanical exfoliation from graphite, provide samples the size and quality of which cannot be predicted. One of goals of today’s research is control of designing of electronic properties of graphene, especially by opening the energy gap on the Fermi level. It is assumed that, because of its specific structure, it could replace silicon chips used for functioning of almost all electronic devices, especially for making computers.

Elite tennis players, Novak Đoković and Andy Murray, use rackets made of this material