Publication Date:
2017-03-29
Description:
Domestic (Bombyx mori) and wild (Antheraea pernyi) silk fibers were characterised over a wide spectral range from THz 8 cm − 1 ( λ = 1.25 mm, f = 0.24 THz) to deep-UV 50 × 10 3 cm − 1 ( λ = 200 nm, f = 1500 THz) wavelengths or over a 12.6 octave frequency range. Spectral features at β -sheet, α -coil and amorphous fibroin were analysed at different spectral ranges. Single fiber cross sections at mid-IR were used to determine spatial distribution of different silk constituents and revealed an α -coil rich core and more broadly spread β -sheets in natural silk fibers obtained from wild Antheraea pernyi moths. Low energy T-ray bands at 243 and 229 cm − 1 were observed in crystalline fibers of domestic and wild silk fibers, respectively, and showed no spectral shift down to 78 K temperature. A distinct 20 ± 4 cm − 1 band was observed in the crystalline Antheraea pernyi silk fibers. Systematic analysis and assignment of the observed spectral bands is presented. Water solubility and biodegradability of silk, required for bio-medical and sensor applications, are directly inferred from specific spectral bands.
Electronic ISSN:
1996-1944
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
