向黑色更近一步:超吸光材料诞生
不知辐射率是不是也很高?导热好,辐射率高,绝佳的散热材料。
近日,NASA发明了一种新型材料,其可吸收99%的可见光,并且不受光线角度影响,导热性是铜的7倍,比钢结实10倍。由于它的这些特性,该材料可被用于采集光能和制作新型望远镜等。该材料通过纳米棒和纳米求制成,其灵感源于一种东南亚超白鳞甲虫。
Black just got blacker: Scientists create the darkest material ever made using microscopic rods and spheres By VICTORIA WOOLLASTON FOR MAILONLINE
Just when you thought scientists had created the blackest material known to man, a group of researchers have gone a step darker.Inspired by the body of an Asian beetle, experts from Saudia Arabia have used the structure of the insect's scales to create an ultra-black material made of a nanorod attached to a nanosphere.This material absorbs 26 per cent more light than the current blackest material made from carbon nanotubes and it could help develop sensitive telescopes that will show the universe more clearly.Absorbent material typically pulls in ultraviolet and visible light but Nasa's material proved it could also capture infrared and far infrared light in the minuscule gaps between the tubes.
During tests, it absorbed more than 99 per cent of the light that hit.Only a small fraction of light reflects off the coating meaning the human eye and sensitive detectors see the material as black.Nasa is hoping that the material will dramatically slash light reflected off deep space equipment that is already straining to detect the faintest and farthest light sources.The material could also be used as a coolant because the blacker the material, the more heat it radiates away.This means the coating could be used on devices that remove heat from instruments and radiate it away to deep space.Last year, researchers from Surrey NanoSystems took this breakthrough a step further with its Vantablack material.It absorbs all but 0.035 per cent of light and is so dark the human eye struggles to discern its shape and dimension, giving the appearance of a black hole.Most of the light is then absorbed as it bounces around creating the illusion of a black hole.
It also conducts heat seven and half times more effectively than copper, and is 10 times stronger than steel.However, these materials rely on organising the carbon nanotubes into thin layers, which means their effectiveness changes based on the angle of the irradiation.By comparison, the latest blackest material, developed by Andrea Fratalocchi and her colleagues at the King Abdullah University of Science and Technology (KAUST) is what's known as a composite nanomaterial made from placing a nanorod onto a nanosphere.This changes the structure meaning there are disordered gaps in the material and it can absorb light at various angles.The researchers were inspired by the ultra-white scales on the Cyphochilus beetle, native to southeast Asia.This level of whiteness is due to the microscopic photonic crystal structure of the scales.
With its nanomaterial, the team inverted this ultra-white property so they could design a material that would be as black, if not blacker, than those materials are white.In particular, the surface of the nanomaterial is so disordered it creates a random network of 'pores' made of long, metallic waveguides.