Researchers at the KTH Royal Institute of Technology in Sweden have developed a wood cellulose aerogel which offers superior thermal performance to typical plastic-based insulation materials.
Developed at the Institute’s Wallenberg Wood Science Centre, the aerogel has been developed through the use of a new method that represents a breakthrough in controlled creation of insulating nanostructures in the pores of wood.
“Biobased strong aerogels could be used to replace current fossil-based aerogels for super thermal insulation, contributing to energy efficiency, bioeconomy, and sustainable society development,” says KTH Assistant Professor Yuanyuan Li.
The process begins with removing the lignin within the wood, which gives the wood its colour and strength. This leaves behind empty pores, called lumen. An ionic mixture is then added to dissolve the cell walls before water is added, which generates nanofibril networks that render the lumen nanoporous.
Thanks to high levels of controls developed throughout the precipitation process, the researchers have been able to create the precise level of nanoporosity to achieve ideal thermal conductivity.
Li says the structure can be used for energy story and conversion, as well as building insulation.
“In packaging, for example, plastic foam such as polystyrene helps prevent heat transfer between objects and the surrounding environment, so it can keep goods cool during the shipment,” she says.
“But in situ formation of nanofibril networks inside wood’s empty spaces can result in wood being highly thermal insulating.”
