Titanium alloys are perhaps one of the most durable materials on our planet. But they have two extremely unpleasant disadvantages: they are very heavy and very expensive. Scientists from the University of Maryland (UMD) came up with an alternative to expensive metals, which can literally "grow on trees." Using an innovative compaction process, the team of researchers managed to create an incredibly solid wood with the strength of metals.
Wood is an extremely versatile material that is used in our life everywhere. However, if you think about it, its properties can be expanded with the help of science, and then it will become even more useful in construction and in many other spheres. The head of the research group of the University of Maryland, Lianbin Hu, has achieved impressive results in recent years in terms of studying this material. Previously, he managed to create transparent wood, effective filters for cleaning water based on charcoal and even sodium-ion batteries based on wood and wood leaves. Of course, the scientist does not intend to stop at the achieved.
The new super wood has gained its strength due to the two-stage process developed by Hu's team. First, the researchers boil the samples of wood in a mixture of sodium hydroxide and sodium sulphite. This makes it possible to partially rid the tree of lignin and hemicellulose. After that, the wood is subjected to hot pressing, which destroys the cell walls and allows the formation of high-level nanofibers of cellulose inside the material. The end result of this process is compacted wood, much larger than usual in terms of strength.
"The new method of wood processing makes it 12 times stronger and 10 times more rigid. This metamaterial may well become a competitor of steel or even titanium alloys, because it is very durable, long-lasting, but at the same time significantly cheaper, "Liangbin Hu told reporters.
One of the tests for strength was the shooting of a sheet of super wood from weapons. While a regular bullet was pierced through with bullets, a sheet of new metamaterial held bullets inside. Scientists claim that the process developed by them can be applied to different types of wood, and it can be scaled on an industrial scale for the simultaneous production of a huge amount of super wood. By the way, during the first phase of production, wood can be given absolutely any shape. The results of the study were published in the journal