Effect of Cobalt Chloride as Filler and PVP on the Optical Properties of PVA/PEG/PVP Blends

Different concentrations of PVA/PEG/PVP blends as well as different composites of cobalt chloride, as filler, embedded in apolymeric blend as a hosting matrix, were prepared by solution casting method. The samples were characterized by a powerful technique as X-ray diffraction (XRD) which shows that the value of crystallite sizes (D) was mainly depending on the content of both of PVP and cobalt chloride (CoCl₂). The studying of the optical properties for the samples was investigated through understanding the obtained results of the absorption and reflection measurements. The absorption spectrum was increasing with increasing each of PVP content in PVA/PEG/PVP blends and the filler content in all the composites of CoCl₂/PVA/PEG/PVP. Also, the concentrations of PVP and CoCl₂ had an influence on the magnitude of the calculated values of the static dielectric constants (ε_∞), the static refractive index (n₀), the moments of the optical spectrum (M₁ and M₃), the average interband oscillator wavelength (λ₀) and the oscillator length strength (S₀). The estimated values of both of the oscillator energy gap E₀, and the dispersion energy E_d, were decreasing by increasing the content of CoCl₂ in the composites CoCl₂/PVA/PEG/PVP 72/5/23 wt %.