Materials

Look out, glass – Scientists develop "transparent wood"

Look out, glass – Scientists d...
A sample of the new material
A sample of the new material
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A sample of the new material
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A sample of the new material

Whether it's being used to make highrises, bicycles or foam insulation, wood is known for being a strong, plentiful, inexpensive and renewable alternative to conventional building materials. Soon, it may even find its way into windows and solar cells – as a cheaper substitute for traditional silica-based glass.

Led by Prof. Lars Berglund, researchers at Sweden's KTH Royal Institute of Technology started by chemically removing lignin from natural wood fibers – lignin is one component of wood cell walls. What was left was a material that was "beautifully white," but still not transparent.

In order to achieve that transparency, the material was mixed with prepolymerized methyl methacrylate (PMMA). This altered the refractive index of the resulting mixture, turning it transparent. Depending on the intended application, the finished product can also be made more translucent, by fine-tuning the wood-to-PMMA ratio.

This actually isn't the first time we've seen wood turned into a transparent material, as nanofibrillated cellulose has been used to create items such as the substrate for wood-based computer chips. According to KTH, however, the new process should be particularly well-suited to large-scale applications and mass production.

The researchers are now looking at increasing the material's transparency, scaling up the manufacturing process, and using a wider variety of woods.

"It's attractive that the material comes from renewable sources," says Berglund. "It also offers excellent mechanical properties, including strength, toughness, low density and low thermal conductivity."

A paper on the research was recently published in the journal Biomacromolecules.

Source: KTH

12 comments
Mr T
So it's not wood, but a heavily chemically treated wood/acrylic composite. Interesting, but not really better than just plain acrylic sheet (or polycarbonate sheet, if you need greater strength), at least not optically. But the low density and greater insulation values may make it attractive, depending on the price. To say it comes from renewable resources is a bit of a stretch, a good proportion of it is still plastic, and the removal of lignin is not exactly a benign process.
noteugene
Always with the naysayers, what's up with these guys? So....now were going to start building transparent houses, high rises & tree houses? ok, cool.
piperTom
So, "the material comes from renewable sources"... unlike, you know, SAND!
Captain Obvious
So, what's the UV resistance of this plastic "wood"?
James.Witte
@Mr. T From what I read, they used the same knowledge/technology used to GMO-ify other plants. As long as it is able to be planted, pollinated and produce seeds that then make new "trees" from those seeds without the lignin, that sounds renewable to me. Personally, if "we" are going to start GMO-ifying "our" trees, I would like to see us produce a tree that can pull more carbon out of the atmosphere. Who knows, maybe if we can find a way to reverse the greenhouse effect at the level it currently exists on Venus, Climate Change will not be as much an issue. @noteugene I vote no to transparent houses. I like my privacy. :-)
MarylandUSA
In 1992, I attended a "science fair" showcasing the work of researchers at America's National Institute of Standards and Technology (NIST). A Soviet-born metallurgist had developed a kind of transparent metal. I smiled and asked him, "Oh, like the transparent aluminum in the Star Trek movie?" My question visibly upset him. "Everyone keeps asking me that," he said indignantly. Then he explained how his approach differed, using terminology only a metallurgist could understand.
Takis
Very nice, but it probably burns. Not an ideal glazing material.
RasielSuarez
If you remove the lignin aren't you just left with cellulose? Cellulose is flammable but translucent (think old film stock). adding the acrylic makes it less flammable but at that point why not skip the cellulose altogether and just use the acrylic? In neither case is it wood anyway.
habakak
I pity the fool....I agree with you Mr T. This is NOT wood, but a tiny part of wood that is heavily treated. Highly misleading and not as renewable as the article would have one believe..
Douglas Bennett Rogers
Might be really good for HPVs and small electric vehicles. A lot like Japanese paper panels. Takes a lot less energy than glass to make. Probably degrades a lot faster. As concerns the anthropogenic greenhouse effect, more than half is due to dessert irrigation.