Optical properties of hydroxyethyl cellulose film treated with nitrogen plasma

K H Mahmoud

doi:10.1016/j.saa.2015.12.029

Optical properties of hydroxyethyl cellulose film treated with nitrogen plasma

Spectrochim Acta A Mol Biomol Spectrosc. 2016 Mar 15:157:153-157. doi: 10.1016/j.saa.2015.12.029. Epub 2015 Dec 29.

Author

K H Mahmoud¹

Affiliation

¹ Physics Department, Faculty of Science, Taif University, Taif, Saudi Arabia; Physics Department, Faculty of Science, Cairo University, Cairo, Egypt.

PMID: 26766604
DOI: 10.1016/j.saa.2015.12.029

Abstract

Hydroxyethyl cellulose (HEC) film has been prepared by casting technique. The prepared sample has been treated with nitrogen plasma at different exposure times. The optical absorption was recorded at room temperature in the wavelength range of 200-800 nm. Absorbance fitting procedure curves revealed a direct allowed transition with optical band gap, Eopt, of 4.9 eV for pristine film, and this value decreases to 4.30 eV for 20 min plasma treatment time. The band tail values (Ee) were found to be increased under plasma time treatment from 1.74 eV in case of the pristine film to 2.20 eV for 20 min. The dispersion of refractive index and complex dielectric constants under plasma treatment was also studied. Variation of color parameters under effect of the plasma treatment is analyzed in the framework of CIE L*U*V* color space.

Keywords: Band tail; HEC; Optical properties; Plasma treatment.