Pressure treating—which involves putting lumber inside a pressurized watertight tank and forcing chemicals into the boards—has been used for more than a century to help stave off the fungus that causes wood rot in wet environments.
Now researchers at the Georgia Institute of Technology have developed a new method that could one day replace conventional pressure treating as a way to make lumber not only fungal-resistant but also nearly impervious to water—and more thermally insulating.
The new method, which will be reported February 13 in the journal Langmuir and jointly sponsored by the Department of Defense, the Gulf Research Program, and the Westendorf Undergraduate Research Fund, involves applying a protective coating of metal oxide that is only a few atoms thick throughout the entire cellular structure of the wood.
This process, known as atomic layer deposition, is already frequently used in manufacturing microelectronics for computers and cell phones but now is being explored for new applications in commodity products such as wood. Like pressure treatments, the process is performed in an airtight chamber, but in this case the chamber is at low pressures to help the gas molecules permeate the entire wood structure.
“It was really important that this coating be applied throughout the interior of the wood and not just on the surface,” said Mark Losego, an assistant professor in the School of Materials Science and Engineering. “Wood has pores that are about the width of a human hair or a little smaller, and we used these holes as our pathways for the gases to travel throughout the wood’s structure.”
As the gas molecules travel down those pathways, they react with the pore’s surfaces to deposit a conformal, atomic-scale coating of metal oxide throughout the interior of the wood. The result is wood that sheds water off its surface and resists absorbing water even when submerged.
Read the rest of the story at Phys.Org
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