安得广厦阳光灿烂，大庇天下寒士俱欢颜。拥有一座透明的木头别墅，是许多人的梦想。2016年美国University of Maryland的胡良兵团队，通过化学改性方法研制出一种新型透明木头，论文发表在著名杂志 《Advanced Materials》上。透明木材是一种新型材料，集美观和实用于一体，因此在建筑、工艺美术等领域有非常广阔的应用前景，成为材料学领域的热点课题。
虽然科学家在小块透明木材的制备上取得成功，但是在透明木材的规模化制备技术上，仍然面临许多挑战。近日，西南林业大学郑荣波副教授课题组，采用绿色环保制造工艺，制作出比前人更大、更厚、更透明的透明木材面板，在透明木材规模化制备研究领域取得了新突破。该研究成果发表在 《Journal of Materials Research》 上，受到瑞典KTH皇家理工学院的材料科学家Lars Berglund的好评。著名科普网站 《Inside Science》对此作了报道。
A green steam-modified delignification method to prepare low-lignin delignified wood for thick, large highly transparent wood composites
Researchers use a more environmentally friendly approach to make larger see-through wood panels than before.
Courtesy of Rongbo Zheng
Friday, February 15, 2019 - 14:45
Yuen Yiu, Staff Writer
(Inside Science) -- Inspired by a technique first developed by botanists during the 1990s, materials scientists in the past few years have been making an almost oxymoronic-sounding material: transparent wood. While the biologists, who were studying the structure of wood, needed only small pieces, materials scientists have proposed applications like load-bearing windows and have focused on scaling up the technique.
Now, researchers from China have brought see-through wood one step closer to commercial application.
According to a paper published in the Journal of Materials Research this month, the authors made panels of transparent wood that are bigger, thicker, and more transparent than their predecessors, while at the same time using a manufacturing process that is more environmentally friendly.
Instead of boiling the wood in bleaching solutions to strip it of its lignin -- the stuff that makes wood opaque -- the researchers steamed the wood with hydrogen peroxide over several hours before backfilling the stripped-down wood panels with transparent resin. According to the authors, their technique can remove more lignin deeper into the wood grains, which makes the final product more transparent. They also claim that by steaming instead of boiling the wood, the wood’s cellular structure can remain relatively intact (chefs would know), which makes the final product stronger.
However, the researchers might have made their experiment easier by using wood panels that were cut across the fibers instead of along the grains, which might have made it easier for the lignin to bleed out. It would be interesting to see how the technique would fare in other cuts of wood, said Lars Berglund, a materials scientist from KTH Royal Institute of Technology in Sweden not involved in the latest research, in an article in the MRS Bulletin.
Before the material is ready for real-world applications, researchers will need to further explore its mechanical properties and the scalability of the manufacturing techniques. But when that day finally comes, we might be able to build greenhouses with tough, transparent wood panes, a sight that could confuse philosophers who say that those who live in glass houses should not throw stones.