If you think of wood as a material, you might describe it with many different adjectives. Sturdy, warm, flexible, maybe pretty, depending on the quality. Transparent is not usually one of them, but researchers have now developed a method to make semi-transparent wood a reality, and it could have interesting applications in the future.
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There is already a component of wood that is transparent: cellulose. However, two other components in wood are not, which are hemicellulose and lignin. It is possible to remove these two, leaving behind just the cellulose, but this would also remove the sturdiness of the material.
A slab of just cellulose is colorless but porous, and in the past, attempts at making transparent wood have used plastics to fill in the pores and provide rigidity. To avoid the plastic aspect, Professor Bharat Baruah took inspiration from a construction technique used in the northeastern Indian state of Assam, where he grew up. Ancient cement in the area was made by mixing sand with rice and egg whites.
“In the modern day, plastic is everywhere, including the devices that we carry around. And it’s a problem when we reach the end of that device’s life. It’s not biodegradable,” Baruah, who’s a professor of chemistry at Kennesaw State University, said in a statement. “So, I asked, what if we can create something that’s natural and biodegradable instead?”
Together with undergraduate Ridham Raval, Baruah placed balsa wood pieces in a vacuum chamber and removed lignin and hemicellulose using a combination of chemicals that included sodium sulfite, sodium hydroxide, and diluted bleach. The material was then soaked in an egg white and rice mixture, and finally, cured with diethylenetriamine, a colorless liquid. That’s how you make a semi-transparent piece of wood – and cheaply, too.
“I want to send a message to my undergraduate students that you can do interesting research without spending thousands of dollars,” Baruah continued.
Testing the wood showed that windows made of the material could be better at insulating a house than glass. The experimental setup involved a birdhouse converted into a tiny home with a single window made out of either the semi-transparent wood or regular glass. When placed under a heat lamp, the wood version kept the temperature inside 5 to 6 °C (9 to 11 °F) cooler compared to the glass version.
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They also installed silver nanowires into certain samples, which allowed the wood to conduct electricity; this was in view of potential electronic applications. Silver is non-biodegradable, so Baruah is investigating materials that could still transmit electricity, but would leave no part behind.
The research was presented at the spring meeting of the American Chemical Society (ACS) in San Diego.
Source Link: All-Natural, Semi-Transparent, And Electrically Conductive Wood Is Now A Reality
