> Most surprisingly, Nxylon remains black even when coated with an alloy, such as the gold coating applied to the wood to make it electrically conductive enough to be viewed and studied using an electron microscope. This is because Nxylon’s structure inherently prevents light from escaping rather than depending on black pigments.
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?
I interpreted this along the lines of it not being a pigment, rather it's black because something about it's physical structure at a small scale causes light to not reflect back. Adding a thin coating of gold would not necessarily change that structure so it would continue not reflecting light.
I wonder if this pattern is considered similar to fractals? Or would that work even better? I recently learned that we have figured out how to produce fractal light from lasers as well which sounds quite interesting and useful.
Maybe the reason radio waves travel poorly through trees is due to the leaves having a fractal-like structure as well? And since light is also just electromagnetic radiation too, it makes sense that this phenomenon could also be used to absorb light itself, if I'm understanding correctly. I wonder if this is how stealth paint on aircraft works?
I'm way out of my depth here, but I think this comparison to the birds of paradise feathers makes the most sense in terms of me visualising what Nxylon would look like with a thin metallic coating
> Adding a thin coating of gold would not necessarily change that structure
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.
This part of the article confused me, because what does a black pigment do if not "inherently prevent light from escaping"? That's kind of just the definition of absorb.
You can see through it at least in part because of the tint/opacity effect, where there is more light on the outside than the inside. It's why you can't see through it the other way around (it's reflective, you don't see the astronauts' eyes).
That would imply the result of overlaying Nxylon with this would be gold-colored, not ultra-black..
Right, but less reflective than solid gold, since some of the light is going _though_ instead of bouncing off
So as you make the layer even thinner than the sun protection on those Apollo visors, you have even more light going through, and even less that can bounce off
What’s the chemistry at play here to achieve this?
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's probably a combination of the surface being black in colour (charcoal), plus a surface texture that absorbs light.
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.
Well they say it doesn't rely on pigments, so I'm inclined to think it uses some sort of nano-structures, like "improved" vantablack. Like a forest where light goes in, but just get's scattered long before it can make its way back out. Ben did a really nice video about that homemade stuff, including (of course) some electron microscope images.
Two things are at play, the lignin (light absorbing) is emphasized and the cellulose is burnt away (light reflecting), and it seems this combined pretty unique lattice system (they use a similar synthetic system when producing regular ultrablack paint but the natural one appears to be more complex) create the blackness.
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.
A room where all the walls, floor, and ceiling are made of this would be pretty disorienting, wouldn't it? Even with a light source that let you see all the people in the room, wouldn't it just look like you're all in a pocket dimension?
Sounds like a great way to build black body emission sources.
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.
Here [0] is the paper in question, it has a chart that shows the reflection rate of this one at around 0.3 - 2%; the paper itself has the following quote for the competitors:
> 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.
If my understanding is correct, Nxylon is lighter than Vantablack (in terms of weight) but reflects slightly more light. This means that it is less effective than Vantablack at absorbing light.
A pity they hadn't read Gene Wolf's _Book of the New Sun_ in which the main character wears robes of "the hue fuligin, which is darker than black, admirably erases all folds, bunchings and gatherings so far as the eye is concerned, showing only a featureless dark."[1] From the Latin for soot.[0]
I think combining Nyx (dark) + xylon (wood) makes perfect sense in a vacuum.
But these researchers have doomed themselves to forever explaining that no, they didn't misspell nylon, and yes, this is something completely different.
The name and the replies to parent remind me of why you should definitely check any name ending '-lon' that you think is a good idea to use: http://news.bbc.co.uk/1/hi/uk/2222783.stm
That particular regime appropriated and tainted a great many symbols which had long persisted with benign or positive connotations for centuries or millennia, let alone literal genocidal poison gas. 'Splainin' "just" is a heavy-lift attempt which is likely to fail for at least another few generations, if not longer.
Just like we can't use the words "agent" or "orange" now for fear of dredging up memories of other atrocities? Parts of the US may have salted the earth with propaganda, but the world kept turning.
From the article: "The team named and trademarked their discovery Nxylon (niks-uh-lon), after Nyx, the Greek goddess of the night, and xylon, the Greek word for wood."
"Professor Philip Evans and PhD student Kenny Cheng were experimenting with high-energy plasma to make wood more water-repellent. However, when they applied the technique to the cut ends of wood cells, the surfaces turned extremely black." -> Yes, usually when you burn wood, you get charcoal. Also surface burning of wood is a popular method of wood treatment in the construction industry.
This is such a HN comment. Every single time some new tech is posted, someone here will make a comment assuming that the group of professionals working on it for years have overlooked some incredibly obvious take that they in all their wisdom came up with after a 30s skim of an article about it.
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?