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“纳米渔网”结构使蜘蛛丝纤维更强

“纳米渔网”结构使蜘蛛丝纤维更强
 
    运用原子力显微镜,X-射线衍射/散射,FTIR分析等各种现代技术组合,刘向阳课题组最近证实了蜘蛛丝和蚕丝具有纳米渔网状网络,该结构是自然界里最柔韧且最坚固的结构之一。单根丝的拉伸力学模式显示了丝纳米纤维中的β-微晶体是“纳米渔网”的交联点。这使得细蜘蛛丝的强度能比淀粉状蛋白样和独立未交联的分子链结构高1000倍。有研究者指出渔网结构中β折叠与β折叠的强相互作用、高有序程度和高β晶体密度是蜘蛛丝拉线具有不同寻常的强度的主要原因。对丝纤维中渔网结构的认识将有助于以一个更通用便捷的方式去设计和合成具有超性能的蛋白纤维或合成纤维。
相关工作已发表在:Adv. Funct. Mater. (2016,  DOI: 10.1002/adfm.201600813):”Nano Fishnet” Structure Making Silk Fibers Tougher, Ruchuan Liu*, Qinqiu Deng, Zhen Yang, Daiwen Yang, Ming-Yong Han, & Xiang Yang Liu*.
http://onlinelibrary.wiley.com/doi/10.1002/adfm.201600813/full


 

实验示意图:从(a)人面蜘蛛 和(b)家蚕蚕茧 中抽丝.(c)该图显示了丝纤维的模拟断裂应力与实际测量有一样的趋势。测量的家蚕 (○) 和人面蜘蛛(●)丝纤维的断裂应力与(d)丝纤维中的β晶体的排列程度(有序性函数f)和(e)纳米渔网结构的网格大小(即β晶体的密度)有依赖关系。以上的实线均是拟合的曲线。(Adv. Funct. Mater. (2016,  DOI: 10.1002/adfm.201600813).
 
“Nano Fishnet” Structure Making Silk Fibers Stronger
 
 
Applying combined technologies of Atomic Force Microscopy, X-Ray Diffraction/Scattering, FTIR analysis etc., Prof Xiang Yang Liu and coauthors recently demonstrated that both spider and silkworm silk fibers have the nano fishnet-like networks, one of the most flexible but toughest structures in this world.  The force patterns of pulling the silk individual fibrils reveal that the b-crystallites in silk nanofibrils are the cross-linking points of the nano fishnets.  This allows spider silk filaments  to have the toughness up to 1000 times, compared with amyloid-like and unlinked string structures. The research indicates that the strong b-sheet-b-sheet interaction, a high degree of ordering and a high density of b-crystallites in the fishnet structure are the main reason for the unusual toughness of spider silk drag lines.  The knowledge on the fishnet structure of silk fibers would shed light on the design and synthesis of either protein or synthetic fibers of ultra-performance in a more generic way. This work was published in Adv. Funct. Mater. (2016,  DOI: 10.1002/adfm.201600813).
 
“Nano Fishnet” Structure Making Silk Fibers Tougher
 
Ruchuan Liu*, Qinqiu Deng, Zhen Yang, Daiwen Yang, Ming-Yong Han, & Xiang Yang Liu*