Transparent wood could be the window of the future | Hacker News Reader

Transparent wood could be the window of the future

usda.gov

111 pointsph0rque64 comments

"The wood is then penetrated with a synthetic polymer called polyvinyl alcohol (PVA), creating a product that is virtually transparent."

Not as exciting as the headline suggested ... plastics with wood fibers as mesh.

I wonder how it will handle direct sunlight for a prolonged period then

I think the trick might be outer pane of glass, inner pane of non-glass. Glass would cut UV and handle the elements. Wood would be safer and insulate better.

You'd want the inner pane to be actual glass, too, so you can clean it with water or handle humidity. But at that point, the gap in a double-paned glass will insulate better.

I wonder if you could sandwich this in to one piece, like automotive glass -- glass/wood/glass?

"Wood fibers" might as well be plastic anyway... See also rayon aka "bamboo" or PLA corn-based plastics, etc

It being a plastic raises a few questions:

- Is it petroleum-based? Looks like the answer is no. [1]

- What's the durability? PVA seems to be very water-soluble [2]

- How's the scratch resistance? I wasn't able to find a source.

[1] https://en.wikipedia.org/wiki/Polyvinyl_alcohol

[2] https://www.cfsanappsexternal.fda.gov/scripts/fdcc/?set=GRAS...

What's the durability? PVA seems to be very water-soluble

In section 4 "Experimental Section", which is oddly behind section 3 "Conclusions", you will find that unless protected by a layer of paint, the material is severely weakened by humidity and subject to swelling and deformation when soaked with water.

> Is it petroleum-based? Looks like the answer is no. [1]

Are you sure? From that link: "PVA is prepared by hydrolysis of polyvinyl acetate"

Follow that and you'll find: "Polyvinyl acetate is prepared by the polymerization of vinyl acetate monomer (free radical vinyl polymerization of the monomer vinyl acetate)."

Which leads to "The major industrial route involves the reaction of ethylene and acetic acid with oxygen in the presence of a palladium catalyst.[6]"

And finally: "Ethylene is produced by several methods in the petrochemical industry. A primary method is steam cracking (SC) where hydrocarbons and steam are heated to 750–950 °C."

PVA seems to be made from fossil fuels (oil, coal, or natural gas) when manufactured at industrial scale, though Wikipedia does a good job of obscuring this. The Wikipedia page mentions that North Korea produces it because it doesn't require oil but they make it with coal instead, which isn't mentioned on that page. The section on environmental considerations mentions only that it's nontoxic and biodegrades, nothing about where it comes from. (Do the fossil fuel / chemical industries have a history of misleading the public? Hmm..)

Honestly, being petroleum based would make me more likely to invest not less. Green energy is garbage unless you're either advantageously situated or enjoy rolling blackouts and meanwhile the developed world is going to fight the developing world mass adopting nuclear tech tooth and nail. So oil is going to be around awhile and by extension its presence is a good signal for supply chain reliability.

Can't you get ethylene from plants like corn?

NileRed on youtube has a cool video detailing the steps to create transparent wood. His result isn’t quite as clear as in the article but the process seems similar.

https://www.youtube.com/watch?v=x1H-323d838

Instead of comparing it to glass, it might be better to compare it to other plastic materials used for windows.

Here's a glass vs. plastic SE Q/A that might be worth reading for context:

https://engineering.stackexchange.com/questions/7408/why-do-...

tldr: PVA is the window of the future, and it turns out that in additional literally anything else, we can also use highly bleached balsa wood to the point where infusing it with PVA makes it transparent enough.

Slightly longer: also, PVA literally dissolves in water, so this is in fact an absolutely stupid idea unless you're also going to coat the resultant panes in chemicals that don't just act as water proofing but are also scratch proof. None of this is even remotely better than using actual glass.

A quick fix to many of the problems you point out would be to coat it on both sides with a thin shell of transparent silica and... uh... oh, never mind.

Glass however is extremely durable and requires no maintenance. When it is manufactured cleanly without any air or other materials intruding during production, it can withstand rain and ice for hundreds of years. I do not see this wood being able to achieve the same durability without intensive care and repainting which will probably cancel out the ecological effects quite soon.

Nitpicking the 25000 metric tons of CO2 quoted in glass manufacturing is essentially inconsequential. Whereas according to [1] aviation produced 915 million metric tonnes of CO2 in 2019 and estimates globally 43 billion tonnes of CO2 produced. Basically, the carbon offset from glass manufacturing by using transparent wood is a rounding error in the grand scheme of things and doesn't even mention the carbon cost of the procedure to create transparent wood, which likely negates the aforementioned offset. Smells like a classic academic attempt to hype the importance of their research. The far more compelling case for this transparent wood seems like the improved insulation. What kind of carbon savings would we see in terms of heating / cooling if we weatherized homes using it? Now you're talking about year after year carbon savings! That's the kind of numbers I would have liked to see in this article, not some paltry appeal to 0.00005% emission savings in glass manufacturing.

[1] https://www.atag.org/facts-figures.html

So because glass manufacturing isn't the biggest source of pollution, we shouldn't do anything about it?

That's like saying we shouldn't bother doing anything about the toxic waste in your local lake because the oceans are still a mess.

And let's not save endangered wildflowers until we get the pandas sorted out.

To quote an internet cliché: Why not both?

This is a less-than-compelling retort. The point isn't "don't do it", the point is "well, why?". OP even admits the more compelling thing here would be to talk about how it's an improvement on glass thermally. The pollution savings are indeed unimportant, but make for good clickbait. That's the annoying part.

Premature optimization is the root of all evil.

—Donald Knuth

It's a waste of time and mental bandwidth to even think about this. The impact is just too small. Better to focus finite energy, attention and political capital on things that actually move the dial.

Exactly, and this is just pragmatism at work.

Sometimes I think people who blindly continue their enviro-rituals are somehow worshipping — it’s more about what it costs them than how much it actually moves the needle.

Caring for the environment is not a religion, and the earth is not a god who demands sacrifice. But it is a precious resource worth protecting.

I was tempted to say this, but am conflicted because I still think it's important for individuals to be conscientious about their actions. Individual actions accumulate to potentially large impacts. However, in general, I agree with you. A large scale, wide impact change motivated by a 0.00005% emissions reduction that is potentially negated by the oxidizing bath and synthetic polymer is simply a distraction. Essentially, emissions from the manufacturing are a red herring and the article almost completely missed the big picture impact this could have.

It's 5 times more thermally efficient than glass. So while the process of making glass may not produce much C02. The process of heating and cooling does.

> unlike glass, it bends or splinters instead of shattering.

That sounds incredibly dangerous. Shattering is a safety feature of modern glass, so you don't have huge jagged chunks to cut an artery if you break it.

https://en.wikipedia.org/wiki/Safety_glass

Also this:

> Could looking through trees be the view to a greener future?

No. The opposite. It means more harvesting of the trees to yield the raw materials that is wood to produce such a glass.

Eh. Forestry can be sustainably harvested. If incentives are set up correctly, I could see this being a net win.

Eh, no. That's exactly what the advocates of pulping industry would like you to believe.

Leaving aside the pollution of the rivers and the land and the air over the years, replacing a forest like the Amazon (example) and the ecosystem within cannot be measured in terms dollar incentives to an industry.

Sustainable harvesting is much like clean coal. The math doesn't actually work, but the advocacy sure does. ;-)

You can have wood without cutting down the Amazon. Besides, I'm not sure if any of the wood I use comes from the Amazon and I think soybeans (and other crops/livestock), lax laws, and lack of enforcement is a much bigger threat to such areas.

Responsible wood farming is quite possible, and it can be forced by strong regulation with the ability to enforce some rules and stop imports of things not meeting rules.

> …I'm not sure if any of the wood I use comes from the Amazon.

Wood comes from a place where a forest (like Amazon) once stood.

> …can be forced by strong regulation with the ability to enforce some rules and stop imports of things not meeting.

I doubt that any of the above is possible. Businesses can always weasel their way out and do what they need to do to make money.

Forestry competes with soy and beef for Amazon land use. Prohibitions of forestry lead to clearing the land for cattle.

CITES has been effective at sustaining forests through maintaining their economic value while reducing production to sustainable levels. Shannon Rogers podcast on the lumber industry has several episodes dedicated to this if you want to learn more.

If we can convert current pastureland into forests and use the forestry products for building materials, you have effectively created an economically incentivized carbon capture system. Pulp plantations are not forests in the ecological sense, but pulp plantations are not the entirety of modern forestry. Current forestry practices lead to a new increase in tree counts (and eventual carbon capture...) and due to these practices the amount of trees in the USA has been trending upwards since we stopped using trees for charcoal.

Where I live, sustainable harvesting includes spraying with glyphosate-based herbicide to control Aspen growth, and then replanting with GMO pines. This creates conditions for massive forest fires since Aspen is a natural firebreak species.

I'd rather see us planting more trees to make glass than building bigger strip mines in the forest to dig up sand for glass.

Strip mines in the forest for sand?

Yes. I've seen plenty of sand mines, and not one of them was on a beach. Too much water. The mining happens inland.

Compared to glassmaking though. At least trees are renewable. We can grow more. We do this now with wood, and it isn't always necessary to cut down virgin forests to get more. Responsible countries have laws about planting more for each tree you cut, and responsible suppliers check up to make sure they get their materials from upstanding companies.

Glass is made from sand - and we have a finite supply. It is definitely not a renewable resource. This isn't getting into the additives and stuff, just the base material (easier to compare).

Glass may not be renewable, but it is very recyclable.

Most window glass is not safety glass.

Regardless, "breaking into splinters rather than shattering" isn't a desirable property of a window material. Safety glass isn't used everywhere because it's more expensive, not because builders want windows to break into larger chunks.

I can pull a splinter out of my finger. I can't pull anything out of a finger that's been lopped off my a shattered pane.

In this context a splinter doesn't have to be tiny, it can be a pointy shard that's 8 inches wide and 2 feet tall. Shattered glass pieces are too small to "lop off" anything. See this image for an illustration of the contrast:

https://www.karseyglass.com/single-post/2019/06/24/Tempered-...

Why would it be bad property for a window material in particular? The bad thing about glass is that it’s sharp, fragile and heavy. If this transparent wood behaves mostly like regular wood, it sounds like an excellent building material.

This is made of balsa wood. If the final result has remotely similar properties to balsa, it is not going to be able to come anywhere near cutting you - balsa's a very soft wood.

Of course if the final result has remotely similar properties to balsa it would also mean that you could just about break it with a hard enough sneeze. Balsa's a very soft wood.

(Though now that I look at the actual abstract it's probably stronger than the chunks of balsa wood I learnt to carve as a kid: "high toughness (3.03 MJ m-3) that is 3 orders of magnitude higher than standard glass (0.003 MJ m-3)" - so maybe you could indeed do some serious damage with shards of clear balsa.)

I'm still holding out for Star Trek's transparent aluminum.

That line always bothered me, because that's pretty much all sapphires are.

Also, gorilla glass. Fancy, but also way less fancy sounding than transparent aluminum.

That's like saying charcoal is pretty much diamonds.

In terms of fundamental ingredients, yes, but it's not quite that simple.

There you go https://www.youtube.com/watch?v=DduO1fNzV4w

But what is wrong with glass? I think we have no shortage of sand.

Hmm... Bringing this up because seeing your comment rung a bell about something I read a year or so ago now...

Google "world sand shortage"

Maybe there's more to it than what immediately meets the eye, but it does seem like there's a bit of a shortage.

I think that is the special* type of sand required for concrete production.

* Concrete requires coarse grains, which are found in river beds and beaches. A lot of the worlds sand is in deserts, which has fine grains due to its age / years of tumbling.

1) use fine sand to make tempered glass

2) break it

3) Now use those small pieces of broken glass as if they were coarse sand to make concrete. Or even better recicle all those old cracked car panes lying in the dumpster.

Problem solved.

Maybe you could even obtain cool semitransparent concrete, if you polish the finished stuff. I dunno. Would be cool stuff in any case.

Also, it is perfectly possible to make the necessary qualities of sand from coarser rocks. It is just more expensive. So the great sand shortage is just a shortage of cheap sand.

Wind blown sand you find in the Sahara is fine for glassmaking. The shortage is really about a specific type of sand useful for it’s mechanical not chemical properties.

The article makes a pretty clear comparison as to why this material is better than glass.

No. They don't say a word about PVA production. They are bringing number of emissions for glass production, but they aren't trying to predict numbers for this technology.

Also, comparison of materials is done without any numbers. Very low-quality article.

> Switching to transparent wood could prove to be cost efficient as well. It is approximately five times more thermally efficient than glass, cutting energy costs.

This is the most exciting part to me. If you’ve ever done a Manual J (load calculation) for an HVAC system, it’s amazing how much energy is lost through windows. Energy.gov says 25-30%.

Doesn’t triple glazing largely address that?

No mention of sound transmission on this or the stackexchange link someone posted.

Why do we need a replacement for glass? Seems to me like a very good material other than the energy required to make it and somewhat limited supply of sand.

Anybody know of any studies or details on how it handles uv a/b/c transmission? mainly uvb vs glass.

PLA is opaque for UV: https://www.researchgate.net/figure/UV-and-visible-light-tra...

So should be similar to window glass in that respect.

But is it rigid enough so it wouldn't warp in sunlight etc? And give a rippled image through the window?

Oh my goodness. The splinters will be horrible.

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