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【期刊论文】Silk fibres produced by artificial reeling are superior to those that are spun naturally.
邵正中, Zhengzhong Shao *, Fritz Vollrath †
NATURE|VOL 418|15 AUGUST 2002 ,-0001,():
-1年11月30日
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【期刊论文】Toughness of Spider Silk at High and Low Temperatures**
邵正中, By Yong Yang, Xin Chen, Zhengzhong Shao, * Ping Zhou, David Porter, David p. Knight, Fritz, Vollath
Adv. Mater. 2005, 17, no.1 January 6,-0001,():
-1年11月30日
The outstanding strength and toughness of certain spider and lepidopteran silkst [1] has aroused considerable interest in recent years, [2] with research focusing primarily on the rela-tionship between molecular structure and mechanical proper-ties. [3] Environmental conditions such as ambient humidity, [4] acidity, [5] and UV radiation [6] a11 affect the mechanical proper-ties of native silks to some degre. [7] pronounced differences in mechanical properties were also observed when conditions such as the speed or temperature at spinning were varied [8] or when the silk was (or had been) submerged in solvents such as water, urea solution, or a range of alcohols, where it con-tracts in varying degrees. [9]
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【期刊论文】Structure and Behavior of Regenerated Spider Silk
邵正中, Zhengzhong Shao, *, †, § Fritz Vollrath, ‡, § Yong Yang, † and Hans C. Thøgersen┴
Macromolecules 2003, 36, 1157-1161,-0001,():
-1年11月30日
Molecule chains of spider silk protein readily self-assemble into ordered structure such as β-sheets when a filament is pulled away from dilute aqueous solution of spider major ampullate silk protein. There is no need to change the pH, the temperature, or the ionic strength of the solution to aid filament formation. Circular dichroism spectroscopy confirmed that the silk protein in such aqueous solution was initially in random coil formation but with time would transform to β-sheets; the process was temperature-dependent. Amino acid analysis showed that reassembled (regenerated) and native spider silks were similar in composition. The morphology and structure of the reassembled silk were investigated by scanning electron microscopy and Raman spectroscopy. The mechanical properties of the reassembled silk were studied in some detail. Our study indicates that reconstituted spider silk self-assembles into respectable filaments. However, it is clear that the spinning process is crucial for the desirable material properties of native silks.
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邵正中, Jinrong Yao, Dahui Xiao, Xin Chen, Ping Zhou, Tongyin Yu, and Zhengzhong Shao *
Macromolecules 2003, 36, 7508-7512,-0001,():
-1年11月30日
With the step-growth polymerization of bis (oligopeptides) and diisocyanates, two silkproteinlike multiblock polymers (P1, P2), containing-(Ala)4-and-(GlyAlaGlyAla)-sequence derived from the crystalline region of spider dragline silk and silkworm (Bombyx mori) silk respectively, has been synthesized successfully. The intrinsic viscosities of P1 and P2 measured in dichloroacetic acid at 25℃ were 0.31 and 0.26dL/g. FT-IR, 13C CP/MAS NMR and WAXD measurements revealed the oligopeptide segments in these multiblock polymers could aggregate spontaneously into β-sheet structure in solid state. In addition, it was also found there were non-β-sheet structures in the synthetic polymers, which indicated such polymers had a solid-state structure similar to that of natural silks.
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邵正中, Zhengzhong Shao a, b, Robert J. Young c, Fritz Vollrath a, *
International Journal of Biological Macromolecules 24(1999)295-300,-0001,():
-1年11月30日
We used wel-defined, fluorescence-free Raman spectra of single silk fibres to study silk ultrastructure. Major ampullate (MA) silk was reeled from the Araneus diadematus spider under controlled conditions. With acustom-built stress-strain gauge, we examined the mechanical properties of this silk both before and after supercontraction in a range of solvents. The solvents were found to modify the material properties considerably. We suggest that the solvents with their different polarities affect different regions of the silk's composite microstructure, in particular the conformation of the molecular chains.
Araneus diadematus, Raman spectroscopy, Mechanical testing, Silk ultrastructure
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