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A Chemical Bath and a Hot-press Can Transform Wood Into a Material That is Stronger Than Steel, Researchers Find (nature.com)
The process, and others like it, could make the humble material an eco-friendly alternative to using plastics and metals in the manufacture of cars and buildings, Nature reported this week. From the report: "It's a new class of materials with great potential," says Li Teng, a mechanics specialist at the University of Maryland in College Park and a co-author of the study published on 7 February in Nature. Attempts to strengthen wood go back decades. Some efforts have focused on synthesizing new materials by extracting the nanofibres in cellulose -- the hard natural polymer in the tubular cells that funnel water through plant tissue. Li's team took a different approach: the researchers focused on modifying the porous structure of natural wood. First, they boiled different wood types, including oak, in a solution of sodium hydroxide and sodium sulfite for seven hours. That treatment left the starchy cellulose mostly intact, but created more hollow space in the wood structure by removing some of the surrounding compounds. These included lignin, a polymer that binds the cellulose. Then the team pressed the block -- like a panini sandwich -- at 100C (212F) for a day. The result: a wooden plank one-fifth the thickness, but three times the density of natural wood -- and 11.5 times stronger. Previous attempts to densify wood have improved the strength by a factor of about three to four.
Generally solid wood is a good choice for many projects due to three key reasons:
1. Cost
2. Workability; can be worked with hand tools and power tools, glues easily and strong
3. Water safe for years with no significant prep work
Steel is a lot stronger per pound, but to join it you either need to use mechanical fasteners or weld it. This requires expensive ($300+) specialized equipment like a welder and/or drill press. Wooden boats are generally good from 15-20 years without major renovations, and are serviceable with major repairs every 10-15 years up to 60-75 years after initial construction. Steel needs to be galvanized, or painted, or sanded and resurfaced every 2-5 years, especially in a saltwater environment (most of the things in your house arrived from asia in a big steel boat).
Super dense wood that's lost most of it's lignin likely is hyper brittle and doesn't machine well. Also, I can only imagine what happens when it's immersed in water. There's a non-zero chance it swells up like a dry sponge when it comes in contact with water or even regular humidity.
moox. for a new generation.
just recycling an infinitely renewable inorganic compound or metal?
I never followed that "logic".
Trees grow ridiculously slowly. And no, you can't just plant a few fast-growers (in a mono-culture even) and call it the same as an ancient complex forest eco system that sustained tens of thousands of species in an elegant balance of cycles!
Meanwhile, metals and generally crystals and materials made from ore are easily recycled in a single day, with some smelting and forging, using only solar energy from places where nothing lives anyway.
"Stronger than steel" is silly anyway. Steel is not very strong. And what do you mean with that word anyway? There's half dozen things that that can mean, and in none is steel quite the best we have. Steel is only popular, because it is very abundant and very cheap, with acceptable properties.
Using trees for building things (apart from decorative furniture and the likes) is as stupid as using fields to grow crops to then turn them into gasoline instead of food.
You're right in that wood does not bend and collapse the way steel does. But what it does do is **feed the fire**. Even wood treated to be less flammable still burns more easily than steel does. (and gives off toxic smoke once the fire overwhelms the chemical resistance. When the wood studs and joists in a home are burned to more than something like 15% of their cross section, they can no longer be expected to carry the load. Wood framed structures collapse more readily than the equivalently steel framed structure. (Note: I am not referring to the thin steel wall studs used to build partition walls, those are never intended to carry any load beyond the weight of the drywall mounted on it. Even a small twist caused by the collapse of an adjoining area totally destroys any load bearing capacity the studs have)
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Oh, it gets much better than that. From Wikipedia:
Similar to fiberglass, Duroplast has limited possibilities for efficient disposal. As discarded Trabants began to fill junkyards, disposing of the bodies inspired creative solutions. One of these was developed by a Berlin biotechnology company, who experimented with a bacterium that would consume the body in 20 days.[2][3] Urban legends, depicted in the movie Black Cat White Cat and described in a song by the Serbian band Atheist Rap, described recycling Duroplast by
feeding the cars to pigs, sheep and other farm animals.
Duroplast flavored bacon? Yum, yum!
After the Berlin Wall fell, Germans voted with their wallets on how they felt about Duraplast cars. Although, the Trabi was overall a crappy car, so it wasn't just the Duroplast. It's amusing that just across the border, the West Germans were building BMWs and Porsches.
That shows you how bad communism is. Under communism, you can take take a nation of Germans, and only make crappy cars with them.
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!