Next Article in Journal
RGDC Peptide-Induced Biomimetic Calcium Phosphate Coating Formed on AZ31 Magnesium Alloy
Previous Article in Journal
Ice as a Green-Structure-Directing Agent in the Synthesis of Macroporous MWCNTs and Chondroitin Sulphate Composites
Open AccessArticle

Silk: Optical Properties over 12.6 Octaves THz-IR-Visible-UV Range

School of Science, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
Department of Laser Technologies, Center for Physical Sciences and Technology, Savanoriu Ave. 231, LT-02300 Vilnius, Lithuania
Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550, Japan
Australian Future Fibres Research and Innovation Centre, Institute for Frontier Materials, Deakin University, Geelong, VIC 3220, Australia
Australian Synchrotron, Blackburn Road, Clayton, VIC 3168, Australia
Melbourne Centre for Nanofabrication, the Victorian Node of the Australian National Fabrication Facility, 151 Wellington Rd., Clayton, VIC 3168, Australia
These authors contributed equally to this work.
Current address: Ruhr-University Bochum, 44801 Bochum, Germany.
Current address: Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
Authors to whom correspondence should be addressed.
Academic Editor: Armando J. D. Silvestre
Materials 2017, 10(4), 356;
Received: 30 January 2017 / Revised: 2 March 2017 / Accepted: 23 March 2017 / Published: 28 March 2017
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 cm1 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. View Full-Text
Keywords: silk; fibroin; biopolymer; terahertz; spectroscopy; solubility; proteins; biodegradable polymers silk; fibroin; biopolymer; terahertz; spectroscopy; solubility; proteins; biodegradable polymers
Show Figures

Graphical abstract

MDPI and ACS Style

Balčytis, A.; Ryu, M.; Wang, X.; Novelli, F.; Seniutinas, G.; Du, S.; Wang, X.; Li, J.; Davis, J.; Appadoo, D.; Morikawa, J.; Juodkazis, S. Silk: Optical Properties over 12.6 Octaves THz-IR-Visible-UV Range. Materials 2017, 10, 356.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Back to TopTop