高分子材料英文论文翻译

《高分子材料研究方法》

课程作业

题目：

AncientMaterial>论文翻译

化学与材料工程学院学院高分子专业

学号XXXXXXX

学生姓名KITTY

指导教师

二〇XX年X月

论文翻译

Science 30 July 2010:

V ol. 329 no. 5991 pp. 528-531

DOI: 10.1126/science.1188936

New Opportunities for an Ancient Material

Fiorenzo G. Omenetto, David L. Kaplan*

Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA.

E-mail: david.kaplan{at}https://www.360docs.net/doc/4919121374.html,

一种古老材料的新机遇

Fiorenzo G. Omenetto, David L. Kaplan*

美国，马萨诸塞州（邮编02155），梅德福，塔夫茨大学，生物医学工程系

邮箱：david.kaplan{at}https://www.360docs.net/doc/4919121374.html,

ABSTRACT

Spiders and silkworms generate silk protein fibers that embody strength and beauty. Orb webs are fascinating feats of bioengineering in nature, displaying magnificent architectures while providing essential survival utility for spiders. The unusual combination of high strength and extensibility is a characteristic unavailable to date in synthetic materials yet is attained in nature with a relatively simple protein processed from water. This biological template suggests new directions to emulate in the pursuit of new high-performance, multifunctional materials generated with a green chemistry and processing approach. These bio-inspired and high-technology materials can lead to multifunctional material platforms that integrate with living systems for medical materials and a host of other applications.

摘要

蜘蛛或桑蚕生成的丝蛋白纤维，是力与美的结合体。从本质上而言，圆形蜘蛛网在生物工程上有着极好的功用，当作为蜘蛛赖以生存的工具时，它展现出了完美的力学构架。迄今为止，在合成材料领域中材料难以同时获得高强度和较好的延展性；而在天然材料中一种结构相对简单的蛋白质通过用水处理即可获得高的强度和较好的延展性。这给了我们一个新的效仿方向——通过绿色化学合成和加工的方法去获得一种新的、高性能的、多功能的材料。这些仿生和高科技材料能够在医药材料和一些其他的应用上使多功能材料平台和生命系统相结合起来。

《高分子材料研究方法》课程作业

M

echanically, silks are outstanding material systems. The toughness of silk fibers is

superior to any of the best synthetic high-performance fibers available today,

including Kevlar (Dupont Advanced Fiber Systems). Although important insights into silk protein self-assembly have been achieved over the past 10 years [1, 2], the mechanisms by which these proteins achieve metastable states in the glands of the spinning organisms remain unclear. This is a remarkable processing achievement that allows the concentration of protein in the glands to reach >30 weight % in water [1], whereas at this concentration most proteins, globular or fibrous, aggregate and precipitate. In the case of silk, this would result in the premature formation of β sheets (crystallization), resulting in insolubility of the spinning dope and blockage of the spinning apparatus, events that would be catastrophic to the silk-spinning organism [2]. The lack of full comprehension of these processing steps has limited the ability to spin reconstituted silk solutions into fibers with properties comparable to those of native fibers.

引他人之言，丝是一类优秀的材料。真丝纤维的韧性优于任何现有的最佳合成高性能纤维，包括Kevlar纤维（杜邦的高级纤维体系）。虽然在过去的十年里已经对丝蛋白的自组装行为有了较为深刻的理解[1, 2]，但对于蛋白质在可纺丝生物体腺内实现亚稳状态的机理尚不明晰。这是一个了不起的处理过程：使蛋白质在腺液内聚集达到质量分数大于百分之三十的浓度[1]并保持亚稳态。然而在人类纺丝加工过程中，大多数蛋白质并不是处于亚稳态，无论是球状还是纤维状，都会发生聚集和沉淀。丝在这种情况下，会过早形成β片层（结晶），导致其不溶于纺丝原液、堵塞纺丝设备，这种情况若是发生在可纺丝生物体身上，将是一场灾难性[2]。由于对可纺丝生物体纺丝处理步骤缺乏充分的理解，我们纺织再造真丝纤维的能力不足，所得再造真丝的性能不能与天然纤维相媲美。

Relationships between silk protein processing and fiber properties suggest that material features are controlled by a combination of the chemistry and the spinning process. Mechanical properties of spider silks are modulated on the basis of spinning conditions, including temperature, reeling rate, and drawing rate, as well as the specific type of silk (Fig. 1) [3, 4]. Silkworm silk fibers are also influenced by process conditions such that properties can be achieved to match those of spider silks [5]. Silks from Bombyxmori obtained at different reeling rates result in stronger but more brittle fibers. Wet spinning with post-spinning treatments can also be used to generate spider silk–like properties and microstructures from silkworm silks [6].

丝蛋白的加工与纤维的性能之间的关系表明，化学合成和纺丝加工过程控制了材料的性能。蜘蛛丝的力学性能是受纺丝的条件所控制的，这些条件包括温度、缫丝速度和牵引速度，以及丝的类型（图1）[3,4]。桑蚕丝纤维也受工艺条件的影响，以实现它的性能与蜘蛛丝的性

论文翻译

能相媲美[5]。丝，以不同的缫丝速率从家蚕中获得，可以使之成为更强更脆的纤维。通过湿法纺丝可以用于制成类似于蛛丝性能和蚕丝微观结构的纤维[6]。

(Fig.1.Mechanical properties of silks. (A) Impressive toughness and relative strength of reeled spider dragline silk. The area under the curve shown indicates fiber toughness or the energy taken up by the material before breaking. In terms of strength-to-weight ratio, the spider silk strength (1.1 GPa) is about equivalent to high-tensile engineering steel (1.3 GPa), yet spider silk has a relative density of 1.3 compared with that of steel at 7.8, when reeled at 20 mm s?1 at 25°C for Nephila edulis. In terms of toughness, spider silk is 165 ± 30 kJ kg?1, which is substantially higher than that of Kevlar 81 (33 kJ kg?1)[1, 5]. (B) Spinning silk from B. mori silkworms at different speeds illustrates control of fiber mechanical properties resulting from processing inputs to complement the importance of chemistry. The data show that the properties can match those of spider silks when spun from the worms at higher rates than native processes. The speeds shown for the lines reflect the rate at which the silk was drawn from the silkworm under controlled conditions at 25°C and are compared with standard degummed silk from cocoons, which are spun from the glands at a natural speed of 4 to 15 mm s?1 at 20°C[3]. (C) Stress strain curves for major ampullate (MA) gland silk (red line) and viscid silk (blue line) from the spider A. diadematus. E init = initial stiffness [4]. (D) Compilation of data from multiple sources and based on data from the

《高分子材料研究方法》课程作业

spider A. diadematus[4]. RH indicates relative humidity.)

（图1 丝的力学性能。(A)图展示出了卷绕蜘蛛牵引丝的高韧性和相对较高的强度。曲线之下的区域显示出了纤维的韧性或者说是材料在断裂前所能承受的施加的能量。就比强度而言，蜘蛛丝的强度(1.1 GPa)约相当于高强度工程钢(1.3 GPa)，但当大木林蛛在25°C以20mm/s的卷绕速度拉丝时，与钢的相对密度7.8相比，蜘蛛丝的相对密度是1.3。就韧性而言，蜘蛛丝是165±30 kJ/kg，远远高于Kevlar 81纤维(33 kJ/kg)[1,5]。

(B)图为家蚕以不同的速度吐丝时丝的应力与应变的关系，说明了加工过程同样控制着纤维的力学性能。数据显示，当通过蠕虫以高速率纺丝时，纤维的性能可与蜘蛛丝相媲美。图中所示的每一条线的纺丝速度，是在25°C从蚕中提取的丝，与标准的从茧中所得的精炼蚕丝（在20°C从腺体以4至15mm/s的自然速率纺丝）做对比[3]。(C)为蜘蛛主腺体丝（红线）和粘丝（蓝线）的应力-应变曲线。E init =初始刚度[4]。(D)为基于测试蜘蛛和其他多种来源的数据资料汇编[4]。RH表示相对湿度。）

The concentration of silk protein increases during the progression from synthesis to spinning in the glands, with changes in chemistry (cations and decrease in pH) and physical features (sol-gel phase transition), along with mechanical alignment in shear flow [1]. Chain alignment is involved in later processing stages, and the internal drawdown of fibers—perhaps including active transport of water, addition of hygroscopic polymers such as sericin (in the silkworm), or other unknown mechanisms—plays an important role in the critical final steps that lead to fiber formation. Silks are not ―squeezed out‖ of the glands but are mostly pulled out, either by the legs of the spider or by the ―figure eight‖ movement of the head of the silkworm during spinning. Rheological studies into the different structures in the spinning gel formed in vivo versus in vitro are instructive in terms of how much native silk material (harvested directly from the gland) differs from reprocessed (fibers resolubilized into solution) silks [7, 8]. This disparity in solution behavior, as discerned from rheological assessments, suggests that there are still substantial knowledge gaps in understanding how to reverse engineer silk protein fibers. Morphological differences in the fiber cross sections among species originate at the spinerettes of spiders and can provide important clues on how processing within the gland, married to the spinning system, can coexist to control morphological features of the final fibers. Thin ribbons, such as those produced by tarantulas, to circular cross sections and other morphologies have been reported depending on the specific spider species. The influence of gland-specific features and process variables have not been studied in detail related to fiber morphology, yet could provide interesting insight into modes to regulate such fiber features.

丝蛋白的浓度在腺体中随着合成及纺丝的进行而逐渐增长，并伴随着化学（生成阳离子和pH值的降低）和物理（溶胶-凝胶相转变）性质上的变化，分子链在剪切流动中机械地