Improvement of optical, dielectric and mechanical properties of a new nanocomposite based on polyvinyl alcohol and layered double hydroxide

In this work, films in the form of poly (vinyl alcohol)/Layered Double Hydroxide (PVA/LDH) nanocomposites were synthesized with different amount of LDH (0%; 4% and 6%), and characterized by X-ray diffraction (XRD), infrared spectroscopy scanning electron microscopy (SEM), impedance spectroscopy and UV-Vis-NIR spectroscopy. Different characterizations were used to investigate the electrical/dielectric, optical and mechanical properties of the nanocomposite films XRD and infrared spectroscopy results showed that clay particles exist in the polymer matrix. Electrical modeling was established using an equivalent electrical circuit consisting of two blocks, and confirmed by fitting the experimental conductivity data according to Jonscher's double power law. Moreover, the reinforcement of the composite matrix by the addition of LDH particles, showed a shift of the relaxations towards the low frequencies, and led to an increase of dielectric constant, conductivity, and absorption of the light in the ultraviolet domain with a decrease of the gap energy. As for the mechanical properties, namely the Young's modulus, is tripled when the clay content is about 6%.