In an era of glbad and steel construction, wood may seem old. But now researchers say they have given the wood a makeover to produce a material that is not only resistant, but also transparent and capable of storing and releasing heat.
Researchers say the material could be used in the construction of energy efficient homes and that they hope to develop a biodegradable version to increase their ecological credentials as an alternative to plastic, glbad or even cement.
"We prepare a material that is multifunctional: it can transmit light very well and it can also store heat. We combine these two functions into one material, "said Céline Montanari of the Royal KTH Institute of Technology in Stockholm, Montanari is presenting the work at the American National Society's spring meeting in Orlando.
To produce the material, the team relied on previous work in which they took balsa wood and removed its lignin, a component of the wood that gives it strength and color. The acrylic, which is not biodegradable and water repellent, was introduced into the remaining tissues where the small pores left by lignin removal and the hollow vessels carrying water in the tree were filled. That, said Montanari, not only helped maintain the structure of the wood but also restored its strength and improved its optical properties. The result was a frosted-looking wood-based material.
In the last work, the acrylic was mixed with another substance called polyethylene glycol, which impregnates the wood well. Crucially, polyethylene glycol also has another feature: when heated, it absorbs energy and melts, but when temperatures fall it hardens, releasing energy in the process. The team says that this property means that its wood-based material, which goes from being semi-transparent to transparent when heated, could be used to make buildings more energy efficient, with the energy captured by the sun during the day. launched inside.
"If you take 100g of this transparent wood material with the [polyethylene glycol] Inside, it can absorb up to 8,000 J of heat, which corresponds basically to what a 1W [bulb] could produce in two hours, "said Montanari, adding that different types of polyethylene glycol are melted at different temperatures so that the team can modify the properties of transparent wood for its application.
Materials that contain substances that can store and release heat in this way are not a new idea in the construction industry, since several types are offered as a new form of insulation to reduce energy consumption. But the team says its approach is different because it uses a natural material that reduces the need for oil-based materials and related CO.two emissions.
However, Montanari said there is still much work to be done, which includes replacing the acrylic with a biodegradable alternative for some applications, increasing the production of the material and carrying out computer models of buildings to see how transparent wood compares with glbad .
Mark Miodownik, professor of materials and society at University College London, who was not involved in the research, warned against engineering that the material is biodegradable, and said it would make the wood less sustainable for the environment, not more.
"We need the construction materials to be carbon sinks and, therefore, they must be recyclable and reusable, not biodegradable," he said, adding that one possibility would be for the new type of wood to recover from buildings and be used in new projects. To the way in which steel is used in "modular construction".
While Miodownik added that the material appeared to be a "solution in search of a problem," he said such an approach has precedents, and noted that it is "how many materials have been invented in the past."