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《高分子材料研究方法》
课程作业
题目：
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
Science 30 July 2010: Vol. 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}tufts.edu
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}tufts.edu
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。
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《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
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