A block of wood before (left) and after treatment to become transparent.
Wood has always been associated with warmth and strength, and is viewed as a material that can be used to make wonderful furniture. It is also synonymous with various shades of brown.
But scientists have now changed all that. Using a two-step process, in a mind-blowing development, researchers at the University of Maryland, College Park, stripped away the plank’s tan and brown colour and made it clear and transparent!
The see-through wood, which the scientists say is stronger and a better insulator than glass, and more bio-degradable than plastic, could one day be used in windows, tables and other building material.
Dr. Liangbing Hu, a materials scientist at the university, and an author of a paper that appeared last week in the journal Advanced Materials, said that they were very surprised by how transparent it could go and felt that this could really open applications that can potentially replace glass and some optical material.
To turn the wood transparent, Hu and his team first boiled it in a bath of water, sodium hydroxide and other chemicals for about two hours. This removed a molecule called lignin, which gives the wood its colour, but left behind its colourless cell structures.
The next step was to pour epoxy over the block, which made it four to six times stronger. It is a two-step process to make wood you can see through. The research team observed that the appealing quality of transparent wood is the series of natural channels that run throughout it, remnants from when it was a living tree.
“The structures, which once pumped water and ions, now direct light along their canals. Glass and plastic typically do not have passageways like these,” they noted and explain: “In traditional material the light gets scattered. If you have this waveguide effect with wood, more light comes into your house.”
The process is not without its limitations. Size is the big issue. So far the largest blocks they have turned clear measured 5’X5’, with thicknesses ranging from paper-thin to 1 cm. The scientists are currently working on scaling the process to make larger blocks.
Meanwhile in Sweden, scientists have also removed lignin from wood with the aim of using it in solar cells.
This article was originally published on:- woodnews.in