A new insulating material has been developed by engineers from the University of Maryland. This material is capable of blocking at least 10 degrees more heat than styrofoam or silica aerogel. The team calls it nanowood and it is 30 times stronger than styrofoam and appears much more environmentally friendly.
Nanowood is produced by taking certain cuts of regular wood and chemically removing all the lignin from it. The lignin is responsible for the brown colour and hardness normally associated with wood. This is removed completely to make white paper that does not yellow with age.
The process to make nanowood is somewhat similar to making paper. The wood is cut while paying attention to its grain and then it is boiled in sodium hydroxide and sodium sulfite. It is then treated with hydrogen peroxide to remove lignin and most of the hemicellulose. It is finally freeze-dried to maintain the structure of the wood rather than mashing it up as in the case of paper.
When the lignin is taken out of the block of wood, you are left with a lightweight, white bundle of cellulose fibres. These fibres act as effective insulators and are better at blocking heat than silica-based materials. They also have anisotropic properties dues their tubular shape.
This means they can conduct in line with the fibres but block the flew in any other direction. Designers can use this property to channel heat around the house as they see fit by changing the orientation of the nanowood. It naturally reflects sunlight and can be produced in a number of sizes depending on the use.
There still need to be a lot of improvements before it can be used commercially. It is wood-based so it is a fire hazard and the time it takes as well as the cost of the freeze-drying process will also play a huge role in its acceptance or rejection from the industry.
If the costs can be brought down, we might see it being commercially used in the not so distant future.