Abstract
Carboxymethyl cellulose film doped with 40 wt% nickel chloride (NiCI(2)6H(2)O) has been prepared by casting technique. The prepared film sample has been treated with nitrogen plasma at different exposure times. The optical absorption was recorded at room temperature in the wavelength range of 190-2,500 nm. From the absorption edge studies, the values of the Urbach energy (E-e) were found to be 0.99eV in case of the pristine film; however, the Urbach energy values were found to be in the range of 0.72-0.92 eV under different plasma treatment times. These energy values indicate that the model based on random fluctuations of the internal fields associated with structure disorder is preferable and consequently transitions occurred through localized and extended states. Modulation of refractive index and complex dielectric constants has been also studied. Variation of color parameters under effect of the plasma treatment are discussed in the frame work of CIE L* u* v* color space. POLYM. COMPOS., 39:1292-1296, 2018. (c) 2016 Society of Plastics Engineers