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New material could replace plastic or glass ∈ construction of energy-efficient homes
Nicola Davis
In an era of glass and steel construction, wood may seem old-school. But now researchers say they have given wood a makeover to produce a material that is not only sturdy, but also transparent and able to store and release heat. The researchers say the material could be used ∈ the construction of energy-efficient homes, and that they hope to develop a biodegradable version soon to increase its eco-friendly credentials as an alternative to plastic, glass or even cement.
“We prepared a material that is multifunctional since it can transmit light very well and also it can store heat. We combined these two functions ∈a single material,” said Céline Montanari of the KTH Royal Institute of Technology ∈Stockholm. Montanari is presenting the work at the spring national meeting of the American Chemical Society ∈Orlando.
To produce the material, the team built on previous work ∈ which they took balsa wood and removed its lignin – a component of wood that gives it strength and colour. Acrylic, which is non-biodegradable and water-repellent, was introduced into the remaining tissues where it filled both the tiny pores \left by the removal of lignin and the hollow vessels that carried water ∈ the tree. That, said Montanari, not only helped maintain the wood’s structure but also restored its strength and improved its optical properties. The upshot was a frosted-looking wood-based material.
In the latest work, the acrylic was mixed with another substance called polyethylene glycol, which permeates wood well. Crucially, polyethylene glycol also has another feature: when it is heated it absorbs energy and melts, but when temperatures fall it hardens, releasing energy ∈ the process. The team say this property means their wood-based material, which goes from semi-transparent to transparent when warmed, could be used to make buildings more energy-efficient, with energy captured from the sun during the day released later into the interior.
However, Montanari said there was plenty of work still to do – including replacing the acrylic with a biodegradable alternative for some applications, scaling up production of the material, and carrying out computer models of buildings to see how transparent wood compares with glass.
(www.theguardian.com/environment/2019/apr/03/scientists-inventtransparent-wood-in-search-for-eco-friendly-building-material. Adaptado)
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