Can Wood Be Stronger Than Steel?
Researchers say they have created a new super-material in the laboratory. They say it is stronger, lighter and costs less than steel.
But the new material is not a product of high technology or a metallic substance. It is wood.
Researchers Liangbing Hu and Teng Li are with the University of Maryland in the United States.
By using a few chemicals, heat and pressure, they have made wood three times denser and 10 times stronger. Hu says that means it can compete with some of the world's strongest materials.
"We're interested in replacing steel and carbon fibers with strong wood structures," he said.
Strong, but not costly
The process does not require any special raw, unprocessed material. Hu said that means the cost of the product will be relatively low. He added, "We can start with very cheap wood, and we can also start with very fancy, expensive wood. But in the end, ultimately we get very similar performance."
The researchers are calling their product "super wood." It is made by partially removing a natural polymer called lignin.
Hu explained that "lignin is like a binder to hold all the components together in natural wood. In our process, we found out to be able to densify the wood completely, we have to remove some of these binders."
Strong chemicals are put on the wood. The chemicals remove about half of its lignin. Then, after being left in extreme heat and pressurized for a day, the treated wood is ready. The researchers say the wood is strong enough to build automobiles, airplanes, wind turbines and more. A report on their findings was published in the journal Nature.
The researchers say super-strength wood would have less of an effect on the environment than the steel or other metals it could replace. However, their process is not pollution-free. It uses some of the same chemicals involved in making paper.
Researcher Teng Li says he and Hu are finding many new ways to use wood, including creating batteries and see-through wood and paper.
"Wood has been existing on Earth more than a million years. And human beings have been using wood for furniture, construction for more than 10 thousand years. And the more we worked on this material, we realized, we have never fully exhausted the potential of this amazing material."
Other scientists are finding new uses for wood as well. Researchers in Sweden have reported making wood-based super-strong fibers for clothing and other materials.
I'm Jonathan Evans.
1.found out 发现
The girl had found out about the goings-on in the factory.
2.as well 也
He should pay and maintain you as well.
3.put on 穿上；增加
She put on her coat and went out.
4.metallic substance 金属
The emery is a hard metallic substance.
5.Hu says that means it can compete with some of the world's strongest materials.
compete with 与...竞争
Kangaroos compete with sheep and cattle for sparse supplies of food and water.
Every time I sing that line, I have to compete with that bloody trombone!
6.But in the end, ultimately we get very similar performance."
in the end 最后；终于
In the end it was his stomach and lungs that packed up.
In the end you have to readjust your expectations.
研究人员称，他们在实验室里开发出一种新的超级材料 。他们称，这种材料比钢铁更坚硬、轻盈且成本更低 。
两位研究人员胡良斌（Liangbing Hu）和李腾（Teng Li）在美国马里兰大学任职 。
通过利用一些化学物质、高温和强压，他们使木材的密度提高了3倍，强度也提高了10倍 。胡良斌表示，这意味着这种木材丝毫不逊于世上最坚硬的材料 。
该过程不需要任何特殊、未加工的原材料 。胡良斌表示，这意味着该产品的成本相对低廉 。他补充说：“我们既可选取价格低廉的木材，也可以采用精致、昂贵的木材 。但是最后的结果相差无几 。”
研究人员称他们的产品为“超级木材 。”这种木材通过去除一种名为“木质素”的天然聚合物而制成 。
胡良斌解释称：“木质素就像粘合剂，能够固定住天然木材内的所有元素 。我们在实验过程中发现，要完全增加木材的密度，需要去除其中一些“粘合剂” 。”
首先，强效的化学物质能够去除约一半的木质素 。然后，经过一天的极度高温和加压之后，处理过的木材就准备就绪了 。研究人员表示，这种木材的强度可用来制造汽车、飞机、风力发电机等等 。这项研究结果发表在《自然》杂志上 。
研究人员表示，这种超级强度的木材对环境的影响远低于可取代的钢铁或其它金属材质 。然而，该木材的加工过程也并非毫无污染 。它使用了一些与造纸类似的化学物质 。
李腾表示：“木材在地球上已经存在了一百多万年 。人类利用木材做家具、建造房屋超过了一万年 。我们意识到，越是研究木材，就会越觉得我们从未充分发掘这一神奇材料的潜力 。”
其他科学家发现了木材的新用途 。瑞典研究人员报告了用于制作服装和其它材料的木质超强纤维 。