Aspects of X-ray diffraction on single spider fibers

Diffraction patterns of silk from several spider species have been obtained by synchrotron radiation using a beam size greater than or equal to 10 mu m. Single fiber diffraction patterns were obtained for fiber diameters down to a few microns. Diffraction patterns recorded with a 10 mu m wide X-ray beam displayed fiber texture. The presence of two fractions of different crystallinity was confirmed for a single Nephila clavipes fiber. The orientation distribution of the polymer chains of the crystalline fraction along the fiber axis was found to be about 23 degrees full-width at half maximum (fwhm). The azimuthal spread of the short-range order fraction was about 86 degrees fwhm. (C) 1999 Elsevier Science B.V. All rights reserved.