热磁处理技术能提高聚合物的性能

时间：2014-11-10 02:51:08

（单词翻译:单击）

For much the same reason LCD televisions offer eye-popping performance, a thermomagnetic processing method developed at the Department of Energy's Oak Ridge1 National Laboratory can advance the performance of polymers. Polymers are used in cars, planes and hundreds of consumer products, and scientists have long been challenged to create polymers that are immune to shape-altering thermal2 expansion. One way to achieve this goal is to develop highly directional crystalline structures that mimic3 those of transparent4 liquid crystal diode, or LCD, films of television and computer screens. Unfortunately, polymers typically feature random5 microstructures rather than the perfectly6 aligned7 microstructure -- and transparency -- of the LCD film.
 
ORNL's Orlando Rios and collaborators at Washington State University have pushed this barrier aside with a processing system that changes the microstructure and mechanical properties of a liquid crystalline epoxy resin8. Their finding, outlined in a paper published in the American Chemical Society journal Applied9 Materials and Interfaces10, offers a potential path to new structural11 designs and functional12 composites with improved properties.
 
The method combines conventional heat processing with the application of powerful magnetic fields generated by superconducting magnets. This provides a lever researchers can use to control the orientation13 of the molecules14 and, ultimately, the crystal alignment15.
 
"In this way, we can achieve our goal of a zero thermal expansion coefficient and a polymer that is highly crystalline," said Rios, a member of ORNL's Deposition16 Science Group. "And this means we have the potential to dial in the desired properties for the epoxy resin polymers that are so prevalent today."
 
Epoxy is commonly used in structural composites, bonded17 magnets and coatings. Rios noted18 that thermosets such as epoxy undergo a chemical cross-linking reaction that hardens or sets the material. Conventional epoxy typically consists of randomly19 oriented molecules with the molecular20 chains pointing in every direction, almost like a spider web of atoms.
 
"Using thermomagnetic processing and magnetically responsive molecular chains, we are able to form highly aligned structures analogous21 to many stacks of plates sitting on a shelf," Rios said. "We confirmed the directionality of this structure using X-ray measurements, mechanical properties and thermal expansion."

分享到：


点击收听单词发音收听单词发音  

1 ridge KDvyh     
n.山脊；鼻梁；分水岭
参考例句：
  • We clambered up the hillside to the ridge above.我们沿着山坡费力地爬上了山脊。
  • The infantry were advancing to attack the ridge.步兵部队正在向前挺进攻打山脊。
2 thermal 8Guyc     
adj.热的，由热造成的；保暖的
参考例句：
  • They will build another thermal power station.他们要另外建一座热能发电站。
  • Volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。
3 mimic PD2xc     
v.模仿，戏弄；n.模仿他人言行的人
参考例句：
  • A parrot can mimic a person's voice.鹦鹉能学人的声音。
  • He used to mimic speech peculiarities of another.他过去总是模仿别人讲话的特点。
4 transparent Smhwx     
adj.明显的，无疑的；透明的
参考例句：
  • The water is so transparent that we can see the fishes swimming.水清澈透明，可以看到鱼儿游来游去。
  • The window glass is transparent.窗玻璃是透明的。
5 random HT9xd     
adj.随机的；任意的；n.偶然的(或随便的)行动
参考例句：
  • The list is arranged in a random order.名单排列不分先后。
  • On random inspection the meat was found to be bad.经抽查，发现肉变质了。
6 perfectly 8Mzxb     
adv.完美地，无可非议地，彻底地
参考例句：
  • The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
  • Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。
7 aligned 165f93b99f87c219277d70d866425da6     
adj.对齐的，均衡的
参考例句：
  • Make sure the shelf is aligned with the top of the cupboard.务必使搁架与橱柜顶端对齐。
8 resin bCqyY     
n.树脂，松香，树脂制品；vt.涂树脂
参考例句：
  • This allyl type resin is a highly transparent, colourless material.这种烯丙基型的树脂是一种高度透明的、无色材料。
  • This is referred to as a thixotropic property of the resin.这种特性叫做树脂的触变性。
9 applied Tz2zXA     
adj.应用的；v.应用，适用
参考例句：
  • She plans to take a course in applied linguistics.她打算学习应用语言学课程。
  • This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。
10 interfaces ad63a35ea2ac8a42233e5ac6cb325d34     
界面( interface的名词复数 )； 接口（连接两装置的电路，可使数据从一种代码转换成另一种代码）； 交界； 联系
参考例句：
  • If the class needs to be reprogrammed, new interfaces are created. 如果class需要重新程序设计，新的interfaces创建。
  • Interfaces solve this problem of evolving code. Interfaces解决了代码升级的问题。
11 structural itXw5     
adj.构造的，组织的，建筑（用）的
参考例句：
  • The storm caused no structural damage.风暴没有造成建筑结构方面的破坏。
  • The North American continent is made up of three great structural entities.北美大陆是由三个构造单元组成的。
12 functional 5hMxa     
adj.为实用而设计的，具备功能的，起作用的
参考例句：
  • The telephone was out of order,but is functional now.电话刚才坏了，但现在可以用了。
  • The furniture is not fancy,just functional.这些家具不是摆着好看的，只是为了实用。
13 orientation IJ4xo     
n.方向，目标；熟悉，适应，情况介绍
参考例句：
  • Children need some orientation when they go to school.小孩子上学时需要适应。
  • The traveller found his orientation with the aid of a good map.旅行者借助一幅好地图得知自己的方向。
14 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
分子( molecule的名词复数 )
参考例句：
  • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
  • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。
15 alignment LK8yZ     
n.队列；结盟，联合
参考例句：
  • The church should have no political alignment.教会不应与政治结盟。
  • Britain formed a close alignment with Egypt in the last century.英国在上个世纪与埃及结成了紧密的联盟。
16 deposition MwOx4     
n.免职，罢官；作证；沉淀；沉淀物
参考例句：
  • It was this issue which led to the deposition of the king.正是这件事导致了国王被废黜。
  • This leads to calcium deposition in the blood-vessels.这导致钙在血管中沉积。
17 bonded 2xpzkP     
n.有担保的，保税的，粘合的
参考例句：
  • The whisky was taken to bonded warehouses at Port Dundee.威士忌酒已送到邓迪港的保稅仓库。
  • This adhesive must be applied to both surfaces which are to be bonded together.要粘接的两个面都必须涂上这种黏合剂。
18 noted 5n4zXc     
adj.著名的，知名的
参考例句：
  • The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
  • Jim is noted for arriving late for work.吉姆上班迟到出了名。
19 randomly cktzBM     
adv.随便地，未加计划地
参考例句：
  • Within the hot gas chamber, molecules are moving randomly in all directions. 在灼热的气体燃烧室内，分子在各个方向上作无规运动。 来自辞典例句
  • Transformed cells are loosely attached, rounded and randomly oriented. 转化细胞则不大贴壁、圆缩并呈杂乱分布。 来自辞典例句
20 molecular mE9xh     
adj.分子的；克分子的
参考例句：
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。
21 analogous aLdyQ     
adj.相似的；类似的
参考例句：
  • The two situations are roughly analogous.两种情況大致相似。
  • The company is in a position closely analogous to that of its main rival.该公司与主要竞争对手的处境极为相似。

©2005-2010英文阅读网