Ultrastructure of Insect and Spider Cocoon Silks

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• 作者：Osnat Hakimi ; David P. Knight ; Martin M. Knight ; Michael F. Grahn ; Pankaj Vadgama
• 刊名：Biomacromolecules
• 出版年：2006
• 出版时间：October 2006
• 年：2006
• 卷：7
• 期：10
• 页码：2901 - 2908
• 全文大小：2299K
• 年卷期：v.7,no.10(October 2006)
• ISSN：1526-4602

文摘

Despite much interest in the extraordinary mechanical properties of silks, the structure of native silk fibers is stillnot fully understood. In the present study, the morphology, topography, and organization of insect and spidercocoon silks were investigated using a range of imaging methods. Field emission scanning electron microscopywas used to observe transverse and longitude structures in silk fibers subjected to tensile fracturing, freeze fracturing,or polishing. In addition, ultrathin sections of silk brins embedded in resin were examined using transmissionelectron microscopy. Finally, dry silk brins were examined by confocal microscopy. The results confirmed theexistence of well-oriented bundles of nanofibrils in all the silks examined and gave an indication of a hierarchicalconstruction of the brin. Observed separation of the microfibrils in fractured brins suggests that the multifibrillarstructure of the silk fiber contributes to toughness by allowing dissipation of energy in the controlled propagationof cracks.