Guest_Jim_* Posted October 8, 2015 Posted October 8, 2015 Graphene is a very interesting material for a number of reasons, with a lot of focus is given to its electrical properties. It also has some curious physical properties, such as the ability to block many materials, even when the graphene is just a film. Now researchers at MIT have investigated how nanoscale pores in graphene behave and may have found ways to control this behavior. Graphene is an atom-thick sheet of carbon atoms, and ideally the sheet looks like chicken wire, but it often possesses defects. The researchers actually wanted these defects to make them the desired nanometer-sized holes. To isolate the pores the researchers used an ion beam to puncture a layer of silicon nitride, which the graphene sheet was then placed on top of. For an ion to pass through both layers, the researchers reasoned they would have to pass through the graphene pores. Next the researchers measured the flows of different salt ions through the setup by measuring changes in the current and voltage from pore to pore and ion to ion. They discovered that some pores were stable while others demonstrated a conductance that swung back and forth. The varying conductance indicates the pores were allowing many kinds of ions through, while the stable conductance suggests those pores were only allowing specific ions through. When the researchers got to work modeling the pore behavior to interpret the measurements they found that a pore's size, electrical charge, and position of the charge all affect its behavior. This suggests that it could be possible to control these pores to selectively allow through only specific ions. Potentially this could be used for sensors, trace metal mining, and water purification systems. Source: MIT Back to original news post Share this post Link to post Share on other sites More sharing options...
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