文章来源:未知 文章作者:meng 发布时间:2010-11-24 03:41 字体: [ ]  进入论坛

The venus flytrap(捕蝇草) plant captures its prey1 when it senses the presence of an insect on the tips of its leaves. An amphiphilic(两性分子的) molecule2 designed by chemists at The City College of New York acts in a similar manner by changing its structure when heated slightly and, then, reverting3 to(回复,归还) its original form when cooled. The finding, reported in the journal Angewandte Chemie, points toward the possibility of designing adaptive soft materials in the lab that take their cues from how nature responds to stimuli4, said Dr. George John, associate professor and corresponding author.

Professor John and colleagues designed the molecule, which has both water-adhering(附着,粘附) and water-repelling(击退,抵制) ends, from cardanol(腰果酚) , a naturally available material found in cashew nut shell liquid. When mixed with water, the molecules5 formed a self-assembled structure called a micelle(胶束) with a water-adhering exterior6 and water-repelling interior.

Warming the micelles to 50 degrees Celsius7 caused them to take on a three-dimensional structure known as a vesicle(泡,囊) that was larger – 200 – 300 nm in diameter – and viscous8, much like oil. "The molecules would stick together, similar to caviar," Professor John said. "When we touched the material with a glass rod, we could draw it out in a thin strand9, much like glue."

Allowing the material to cool resulted in the molecules reverting to their original micellar structure. When they were reheated, they would again take on the viscous form.

The change in structure resulted because, while heating caused the micelles to rearrange, they began to interlock in a bi-layer arrangement and eventually undergo curvature(弯曲) . Directional hydrogen bonding of the amide linkages10 and stacking of the aromatic11 ring groups, further stabilized12 the assembly.

The objective of the research is to study responsive systems, Professor John said. "If we can understand the influence of saturation13(饱和) at the bi-layer stage, we can regulate the adaptive response to stimuli." This will require investigating the number of micelles needed in a mixture and where they need to be positioned.


1 prey g1czH     
  • Stronger animals prey on weaker ones.弱肉强食。
  • The lion was hunting for its prey.狮子在寻找猎物。
2 molecule Y6Tzn     
  • A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈?f婘??妈?成的。
  • This gives us the structural formula of the molecule.这种方式给出了分子的结构式。
3 reverting f5366d3e7a0be69d0213079d037ba63e     
恢复( revert的现在分词 ); 重提; 回到…上; 归还
  • The boss came back from holiday all relaxed and smiling, but now he's reverting to type. 老板刚度假回来时十分随和,满面笑容,现在又恢复原样了。
  • The conversation kept reverting to the subject of money. 谈话的内容总是离不开钱的事。
4 stimuli luBwM     
  • It is necessary to curtail or alter normally coexisting stimuli.必需消除或改变正常时并存的刺激。
  • My sweat glands also respond to emotional stimuli.我的汗腺对情绪刺激也能产生反应。
5 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
分子( molecule的名词复数 )
  • 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。
6 exterior LlYyr     
  • The seed has a hard exterior covering.这种子外壳很硬。
  • We are painting the exterior wall of the house.我们正在给房子的外墙涂漆。
7 Celsius AXRzl     
  • The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
  • The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。
8 viscous KH3yL     
  • Gases are much less viscous than liquids.气体的粘滞性大大小于液体。
  • The mud is too viscous.You must have all the agitators run.泥浆太稠,你们得让所有的搅拌机都开着。
9 strand 7GAzH     
  • She tucked a loose strand of hair behind her ears.她把一缕散发夹到了耳后。
  • The climbers had been stranded by a storm.登山者被暴风雨困住了。
10 linkages f6a08b944f7078520423ad9f699def40     
n.连接( linkage的名词复数 );结合;联系;联动装置
  • Only the thermosetting resins provide a strong cohesive forces; this is due to molecular cross linkages. 只有热固性树脂具有巨大的凝聚力,这是由于分子交错链所造成的。 来自辞典例句
  • The linkages between the stable units must be as near as possible of equal stability. 稳定链节之间的键必须有尽可能接近的稳定性。 来自辞典例句
11 aromatic lv9z8     
  • It has an agreeable aromatic smell.它有一种好闻的香味。
  • It is light,fruity aromatic and a perfect choice for ending a meal.它是口感轻淡,圆润,芳香的,用于结束一顿饭完美的选择。
12 stabilized 02f3efdac3635abcf70576f3b5d20e56     
v.(使)稳定, (使)稳固( stabilize的过去式和过去分词 )
  • The patient's condition stabilized. 患者的病情稳定下来。
  • His blood pressure has stabilized. 他的血压已经稳定下来了。 来自《现代英汉综合大词典》
13 saturation wCTzQ     
  • The company's sales are now close to saturation in many western countries.这家公司的产品销售量在许多西方国家已接近饱和。
  • Road traffic has reached saturation point.公路交通已达到饱和点。
TAG标签: water molecule stimuli