I don't follow this at all. If it's coated with an alloy, Nxylon isn't on the surface of the object anymore, the alloy is. So the alloy should be reflecting light. What am I missing?
^ pure conjecture
My confusion is that I would normally expect a layer of gold not to permit any light to pass through. The underlying structure wouldn't be receiving any light, so there would be no photons to trap. Apparently a layer of gold can be applied thinly enough to transmit appreciable light, though.
> Far lower reflectance values have been achieved with materials containing aligned carbon nanotubes (CNT), for example a low-density CNT array (0.045%),[11] the coating Vantablack (0.035%)[7] and a CNT-metal foil (0.005%).[12] The current holder of the “record” for a low reflectivity material (<0.0002%) is an ion-track micro-textured polymer with anti-backscatter matrix.[13]
So they're arguing that it's on-par with Vantablack but not the newer materials.
[0] https://onlinelibrary.wiley.com/doi/10.1002/adsu.202400184
Does it burn “lighter” compounds away to leave dark ones behind? Does it cause a reaction to turn lighter compounds darker? I couldn’t see details of the mechanism. Which is important since presumably some mechanisms would give a hint that the process can be tried on other materials or types of wood.
The article mentions it works on other types of wood but doesn’t explain why, or if it works on all woods.
It brings to mind the way feathers and insects often have brightly-coloured parts that aren't due to pigment but rather the microstructure preferentially absorbing/reflecting specific wavelengths, giving a colour.
https://en.wikipedia.org/wiki/Structural_coloration
Similarly, I wouldn't be surprised if the microstructure is tuned to work best (lowest reflectance) in the visible light range.
EDIT: limited wavelength range also applies to other "super-black" materials https://en.wikipedia.org/wiki/Super_black#Technology
Burning the end-grain wood makes a particularly complex porous structure that minimizes the chance of reflected light escaping ("velvety").
It seems the most straightforward spelling (and easier to pronounce by looking at it if you are taking any kind of cues from the rest of loan words in the language) would have been Nyxlon.
Just panel the interior of a box with this stuff and put a hole in one wall.
It does depend on the spectral properties a lot. Figure 3 in https://onlinelibrary.wiley.com/doi/10.1002/adsu.202400184 seems to indicate that the behavior in the very near infrared will be pretty good. It stands to reason that this behavior could be optimized by process improvements.
Making this at home will be quiet interesting.
