X-ray diffraction study of nanocrystalline and amorphous structure within major and minor ampullate dragline spider silks.
Soft Matter
; 8(25): 6713-6722, 2012 Jul 07.
Article
em En
| MEDLINE
| ID: mdl-23569461
ABSTRACT
Synchrotron X-ray micro-diffraction experiments were carried out on Nephila clavipes (NC) and Argiope aurantia (AA) major (MA) and minor ampullate (MiA) fibers that make up dragline spider silk. The diffraction patterns show a semi-crystalline structure with ß-poly(l-alanine) nanocrystallites embedded in a partially oriented amorphous matrix. A superlattice reflection 'S' diffraction ring is observed, which corresponds to a crystalline component larger in size and is poorly oriented, when compared to the ß-poly(l-alanine) nanocrystallites that are commonly observed in dragline spider silks. Crystallite size, crystallinity and orientation about the fiber axis have been determined from the wide-angle X-ray diffraction (WAXD) patterns. In both NC and AA, the MiA silks are found to be more highly crystalline, when compared with the corresponding MA silks. Detailed analysis on the amorphous matrix shows considerable differences in the degree of order of the oriented amorphous component between the different silks studied and may play a crucial role in determining the mechanical properties of the silks.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Soft Matter
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos