德国科学家制造出世界最轻材料
A network of porous(多孔渗水的) carbon tubes that is three-dimensionally interwoven(互相编织) at nano and micro level -- this is the lightest material in the world. It weights only 0.2 milligrams per cubic centimetre, and is therefore 75 times lighter than Styrofoam, but it is very strong nevertheless. Scientists of Kiel University (KU) and Hamburg University of Technology (TUHH) have named their joint creation "Aerographite." The scientific results were published in the scientific journal Advanced Materials on July, 3rd.
The properties
It is jet-black, remains stable, is electrically conductive, ductile(柔软的) and non-transparent. With these unique properties and its very low density the carbon-made material "Aerographite" clearly outperformes all similar materials. "Our work is causing great discussions in the scientific community. Aerographite weights four times less than world-record-holder up to now," says Matthias Mecklenburg, co-author and Ph.D. student at the TUHH. The hitherto lightest material of the world, a nickel material that was presented to the public about six months ago, is also constructed of tiny tubes. Only, nickel has a higher atomic mass than carbon. "Also, we are able to produce tubes with porous walls. That makes them extremely light," adds Arnim Schuchard, co-author and Ph.D. student at Kiel University. Professor Lorenz Kienle and Dr. Andriy Lotnyk were able to decode the material's atomic structure with the aid of a transmission electron microscope (TEM).
Despite of its low weight Aerographite is highly resilient. While lightweight materials normally withstand compression but not tension, Aerographite features both: an excellent compression and tension load. It is able to be compressed up to 95 percent and be pulled back to its original form without any damage, says professor Rainer Adelung of Kiel University. "Up to a certain point the Aerographite will become even more solid and therefore stronger than before," he points out. Other materials become weaker and less stable when exposed to such stress. "Also, the newly constructed material absorbs light rays almost completely. One could say it creates the blackest black," acknowledges Hamburg's Professor Karl Schulte.