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Journal of Spectroscopy
Volume 2015 (2015), Article ID 879296, 7 pages
Research Article

Tuning the Refractive Index and Optical Band Gap of Silk Fibroin Films by Electron Irradiation

1Department of Studies in Physics, Mangalore University, Mangalagangotri, Mangalore 574 199, India
2School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA

Received 2 March 2015; Revised 8 April 2015; Accepted 12 April 2015

Academic Editor: Austin Nevin

Copyright © 2015 S. Asha et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The Bombyx mori silk fibroin (SF) films were prepared by solution casting method and effects of electron beam on the optical properties and optical constants of the films have been studied by using UV-Visible spectrophotometer. Optical properties like optical band gap , refractive index n, extinction coefficient k, optical conductivity , and dielectric constants of virgin and electron irradiated films were determined by using UV-Visible absorption and transmission spectra. It was found that the reduction in optical band gap and increase in refractive index with increasing radiation dosage was observed. It is also observed from results that there is increase in dielectric constants with increasing photon energy. The observed optical changes have been tried to be correlated with the structural changes, revealed through FT-IR spectroscopy. The present study is quite important for tailoring the optical responses of SF films as per specific requirements.