Studying the effect of concentration on spectral and optical properties of chitosan polymer

Abstract

Due to its noteworthy physico-chemical behaviors, the chitosan (CS) biopolymer presents a compelling alternative to conventional biomaterials. By measuring the emission spectra at a spectrofluorophotometer in different concentrates (1x10 -4 , 1x10 -5 , and 1x10 -6 ) M, the spectral characteristics of the CS polymer were obtained. The crystallinity of the CS polymer was determined by X-ray diffraction (XRD) analysis, which shows only one dominant peak indexed to the orthorhombic structure. With a drop in solution concentration, there was a shift toward the shorter wavelength and a decline in quantum yield. Using a UV-Vis spectrophotometer, the optical properties of the CS polymer, including its refractive index, absorption coefficient, energy band gap, extinction coefficient, and dielectric constant, have been studied. It was observed through the results that the optical parameters are linearly dependent with concentration. In contrast to the optical energy gap, which decreases with increasing concentration .