As part of a research last year, Japanese scientists developed a new form of glass that is reportedly as strong as steel. This time around, however, a team from the University of Maryland has come up with an innovative technique of creating see-through wood that is at the same time remarkably durable and robust.
Although widely used as a construction material, regular wood is known to be susceptible to rotting as well as damage by insects. Glass, on the other hand, breaks easily, resulting in the leakage of heat into and out of a building. According to Liangbing Hu, the study’s leader, the newly-created material combines the best qualities of both wood and glass.
Recently published in the Advanced Energy Materials journal, the research talks about the amazing properties of the see-through wood. For instance, it boasts “high impact energy absorption that eliminates the safety issues often presented by glass”. Unlike glass, this new material actually remains unbroken even when whacked with a hammer.
While the exact process of developing the translucent wood has not yet been revealed, Martha Heil of the university’s Nanocenter stated that it involves treating wood with a combination of bleach and epoxy. Once the it has been soaked in a solution of sodium hydroxide (or lye), the wood is treated using a special chemical that removes all traces of the compound lignin, which is what lends wood most of its properties. These include its brown color, strength as well as resilience against annoying pests.
Using this method, a thin sheet of wood can be bleached in under 10 minutes, as compared to 24 hours in case of a bigger log. After this, the substance is soaked in what the scientists call “clear liquid”, which in turn makes the wood “very friable” and even “crunchy”. The following image shows how the see-through wood looks like if it hasn’t been bleached entirely.
Once the soaking is complete, the clarified wood is dipped into an epoxy solution, similar to glue. It is this step, the researchers claim, that makes the wood translucent and incredibly strong. This is because the epoxy causes the porous cellulose tubes present in wood to transform into efficient light diffusers. In addition to being see-through, the see-through wood is believed to be a much better thermal insulator than ordinary glass. Tian Li, a materials scientist at the university, explained:
You have a uniform consistent indoor lighting, which is … independent of where the sun is… Our transparent wood also has a much lower thermal conductivity compared with glass, making it a better thermally insulating building material with a lower carbon footprint.
Thanks to the breakthrough, wood could take the place of glass as a renewable building material that is also incredibly versatile. At present, the team is trying to scale up the manufacturing process to industrial level. The scientists added:
Making transparent wood requires using epoxy, so it’s not very environmentally friendly right now… [We are] experimenting with other types of clear stiffeners, which will include PVP (polyvinylphenol), which is recyclable.
Source: University of Maryland