Characterization and study of polymer nanocomposites pre and post modification induced by laser ablation / Dana Saif Elddin Akil ; Supervised Adel Mohamed Badawy Shehap

Thesis (Ph.D.) - Cairo University - Faculty of Science - Department of Physics

In this work, TiO2 nanopatricles were added in different ratios to the Polyvinyl alcohol(PVA) to fabricate nanocomposite with new physical properties.Casting method were used to fabricate the nanocomposite thin films along with Sonification .XRD diffraction was performed to understand the crystalinity nature of the films. UV- Visible spectra and particularly the absorption edge, band tail and optical constant are used to provide a good idea about structurel changes of the composite films.Single oscillator model were used to study the dispersion parameters. Fourier transform infrared (FTIR) spectroscopy has been studied to understand the mechanism of interaction The thermogravimetric analysis (TGA) was used to characterize the stability of the obtained films and the differential scanning calorimeter (DSC ) in order to understand the glass{u2013} transition temperature and the degree of crystalinity.. The effect of the laser irradiation with different wavelengths on the properties of the nanocomposites were studied using( UV-Vis) spectrum ,XRD ,and FTIR spectroscopy after laser irradiation of the films in both cases befoe damage and after ablation . Sanning electron microscope (SEM) and Atomic force microscope (AFM) were used to study the change of the surface after laser irradiation and to measure the diameter and the depth of the ablated region in of the nanocomposites for different nanoparticles ratios

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