A group of scientists working with Airbus from the Department of Advanced Technology at the University of Surrey said they have created a multifunctional protective nanocoating for spacecraft. It refers to composite structures and allows not only to cool the surface of satellites from 120 ° C to 60 ° C, but also has the ability to collect energy from solar radiation for use on board to heat appliances or generate electricity.

As you know, the onboard equipment of satellites must not only be cooled, but also heated, depending on whether it is turned towards the Sun or is in the shade. The consequence of this is, as a rule, a cumbersome combined system of thermal protection and heat dissipation. This, in turn, forces the payload to be reduced, sending service systems for cooling and heating equipment into orbit instead.

The solution proposed by the British scientists is compact and largely resembles the painting procedure, although very complex with alternating high-tech operations, including the deposition of material in the presence of plasma. It is called a multifunctional nanobarrier structure (MFNS) and can even be applied to antennas, since it has dielectric properties. The multilayer protective nanobarrier consists of a buffer layer of poly-para-xylylene (p-xylylene) and a layer of diamond-like carbon superlattice, which gives it a mechanically and environmentally superstable structure.

MFNS is applied to the surface of satellite and equipment structures using Plasma Chemical Vapor Deposition (PECVD). This process takes place at room temperature and can be carried out on heat sensitive substrates. In addition, the parameters of the coating can be changed in one direction or another and, thereby, adjust the absorption capacity in the ultraviolet and visible parts of the spectrum while maintaining the emissivity in the infrared range (diffused cooling).

Interestingly, the coating self-reconfigures itself in orbit "due to the balanced effects of ultraviolet radiation and atomic oxygen." Atomic oxygen is formed from molecular oxygen in the upper atmosphere under the influence of ultraviolet radiation and it is there in excess for the desired reaction.

As for the collection of thermal energy by the coating, according to the developers, this can be achieved by creating highly absorbing structures with a photothermal conversion efficiency of up to 96.66%. This is facilitated by the deposition of a nitrogen-doped diamond-like carbon superlattice layer, which leads to improved optical absorption in a wide spectral range.

All together it is claimed to make MFNS a candidate for many thermal applications such as photodetectors, radiators, smart heatsinks and power harvesting used in satellite systems and beyond.