[HN Gopher] Nxylon: New super-black material made from wood
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Nxylon: New super-black material made from wood
Author : throwaway2562
Score : 160 points
Date : 2024-08-03 16:06 UTC (4 days ago)
(HTM) web link (news.ubc.ca)
(TXT) w3m dump (news.ubc.ca)
| oniony wrote:
| This, different article, https://www.earth.com/news/new-super-
| black-wonder-wood-calle..., suggests the process is high-energy
| plasma affecting the cut ends of the basswood fibres.
| bradrn wrote:
| That article has a paper link:
| https://doi.org/10.1002/adsu.202400184
| hoseja wrote:
| How does it compare to the other super-black materials, the
| Vantablacks and the like?
| HPsquared wrote:
| Probably less carcinogenic.
| Cthulhu_ wrote:
| I dunno, it looks like they're creating carbon
| nanostructures; while wood carbon / soot seems fairly benign,
| I still wouldn't want to breathe it.
| cenamus wrote:
| And tar/pitch is definitely carcinogenic
| tetris11 wrote:
| that's what a lot people with wood burners _used_ to say...
| throwanem wrote:
| Yeah, but everybody chain-smoked from age 3 in those days,
| so it's not easy to tell.
| Cthulhu_ wrote:
| 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.
|
| [0] https://onlinelibrary.wiley.com/doi/10.1002/adsu.202400184
| shibbidybop wrote:
| From your numbers Vantablack is 0.035%, whereas the new
| process bottoms out at 0.3%. So they're within 10x of
| Vantablack, but not on the same level.
| Alifatisk wrote:
| 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.
| dbacar wrote:
| "The researchers have developed prototype watches and jewelry"
| What kind of a research team is this, fashion? :)
| tetris11 wrote:
| Also, the black parts there really didn't look that dark.
| swiftcoder wrote:
| They are also all watch designs that I get served instagram
| ads for, coincidentally
| nvalis wrote:
| I recognized the right watch immediately to be this one
| [0]. But i guess they just replaced parts of the watchfaces
| with their material?
|
| [0]: https://www.holzwerk-uhren.de/en/products/holzwerk-
| eifel
| MisterBastahrd wrote:
| Those watches have crystals on them.
| kingkongjaffa wrote:
| 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.
| cenamus wrote:
| 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.
|
| https://www.youtube.com/watch?v=Xr1AiExSAnU
| flir wrote:
| Maybe the cut cell acts like a hemispherical shell coated in
| carbon. Light enters, bounces around inside a couple of
| times, gets absorbed?
| neom wrote:
| 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.
| HPsquared wrote:
| 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.
|
| 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
| Scaevolus wrote:
| Check the paper, especially figure 5:
| https://doi.org/10.1002/adsu.202400184
|
| Burning the end-grain wood makes a particularly complex porous
| structure that minimizes the chance of reflected light escaping
| ("velvety").
| barrenko wrote:
| Hopefully the writers of Parks & Recreation will be aware of this
| research when writing the second reunion show.
|
| https://youtu.be/pTme7k5sV-o?si=sbAYH5FAg4n4G4LS
| parpfish wrote:
| How much more black could it be? None. None more black.
| Hnrobert42 wrote:
| The ceiling and wall tiles mentioned at the very end of the
| article sound really cool.
| pmcarlton wrote:
| 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?
| digging wrote:
| > 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?
| vczf wrote:
| A layer of very thin gold can be transparent.
| digging wrote:
| I see, thanks for filling that in.
| wlesieutre wrote:
| Famously seen on the Apollo space suit sun visors. Their
| gold layer is thick enough to look gold, but thin enough
| that you can see through it:
|
| http://heroicrelics.org/apollo-wwwttm/apollo-
| suit-a7l-leva-v...
|
| http://heroicrelics.org/apollo-wwwttm/apollo-
| suit-a7l-leva-v...
| ComputerGuru wrote:
| 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..
| loaph wrote:
| 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.
|
| ^ pure conjecture
| pb060 wrote:
| I believe it's something called "structural absorption",
| similar to what happens on birds of paradise feathers [1]
|
| [1] https://www.nature.com/articles/s41467-017-02088-w
| digging wrote:
| > 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.
| xelamonster wrote:
| 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.
| peter_d_sherman wrote:
| https://www.youtube.com/watch?v=pAgnJDJN4VA
| ted_dunning wrote:
| 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.
| ComputerGuru wrote:
| > Nxylon (niks-uh-lon), after Nyx
|
| 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.
| YeGoblynQueenne wrote:
| I read it as "N-xylon", where "xulon" is wood in Greek.
| groby_b wrote:
| Looking at the watch photographies, how is this "super-black"?
| fernly wrote:
| 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]
|
| [0] https://www.merriam-webster.com/dictionary/fuliginous
|
| [1] http://www.technovelgy.com/ct/content.asp?Bnum=1495
| ljsprague wrote:
| Does it rub off?
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