Controlling the optical and mechanical properties of polyvinyl alcohol using Ag2S semiconductor for environmentally friendly applications

摘要

In this work, the optical and mechanical properties of polyvinyl alcohol (PVA) composite have been controlled using Ag2S semiconductor for environmentally friendly applications. Different weight (wt.) ratios percentages (0, 0.01, 0.1, 0.5, 1.0, 5.0 and 10.0%) of Ag2S/PVA composites were prepared using solution casting technique. The prepared composite films were analyzed using a scanning electron microscope (SEM), X-ray diffraction (XRD), spectrophotometry and dynamic mechanical analyzer techniques. XRD measurements ensure the semi-crystalline structure of plain PVA and Ag2S/PVA composites. The optical properties including the absorption, transmittance, reflectance, absorption coefficient, extinction coefficient, refractive index and dielectric constant as a function of wavelength are studied. The deduced transition energy between molecular orbital band edges (E-g) of Ag2S/PVA composite films decreases from 5.39 eV to 1.06 eV as the wt. % ratio of Ag2S/PVA composite increases from 0 to 10.0%. This decrease in E-g is mainly attributed to the formulation of new energy levels between the polymer's molecular orbital band edges. The mechanical properties including storage modulus, loss modulus, stiffness and loss factor (tan delta) as a function of swept temperature have been investigated. The estimated glass transition temperature (T-g) of the prepared films decreases from 54.5 degrees C to 34.7 degrees C as the wt. % ratio of Ag2S/PVA composite increases from 0 to 10.0%. These novel results present Ag2S/PVA composites as an active candidate in environmentally friendly applications.