VANTABLACK (TM) - 'DARK MATERIALS'

Heralded as the darkest material ever - Surrey Nanosystems showcases vantablack and its mind bending optical properties.

Properties:

as described above vantablack's most notable property is its ability to absorb light, it is able to absorb 99.965% of all incident light. The name "V-A-N-T-A" is in fact an acronym which stands for: "vertically aligned nanotube array" and it is exactly that. The material consists of row after row of upward facing carbon nanotubes:

Up close the array resembles a stack of drain pipes! These nanotubes act like traps - incident light is refelected off the inside of the tubes many times. Each time it is reflected some of the light is converted to heat, this results in the almost total absorbtion of light.

Production:

there are many different ways of producing CNTs. The majority work by vapourising some form of carbon (usually graphite) and allowing it to solidify under specific conditions often with a catalyst to produce the desired form of carbon. The most widely used method currently is 'chemical vapour deposition':

a specific substrate (surface for nanotubes to grow on) is prepared by adding metal catalyst particles. The size of these metal catalyst particles will affect the diameter of the nanotubes which are produced allowing the tube widths to be tailored for optimum absorbtion. The substrate is then heated to high temperatures and a carbon containing gas with a process gas is fed into the reactor. The nanotubes form specifically at the metal catalyst sites to create a structure like the one above. The producers of vantablack (surreynano systems) have also patented a number of techniques for CNT growth which involve stimulating growth in specific regions and tailor making metal catalyst for better control over the density and diameter of the nanotube array.

Applications:

vantablack has interesting potential use in optical sensors such as telescopes and cameras as it is able to eliminate stray light. This is of particular use as stray light is a limiting factor on the effectiveness of such equipment as it decreases the signal to noise ratio. If stray light were reduced in telescopes for instance this would increase their sensitivity and allow even fainter astronmical bodies to be viewed.

Another interesting potential use of vantablack is in thermal camouflage. It's absorbance of light frequencies such as infrared mean it could be used for instance to shield the IR given out by the engine of a tank or aircraft making it less susceptible to tracking / detection systems:

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