POLYVINYLPYRROLIDONE/SILICON DIOXIDE COMPOSITE THIN FILMS - PREPARATION AND ANALYSIS OF PROPERTIES

The purpose of this study was to produce composite thin films with polyvinylpyrrolidone (PVP) matrix with nanoparticles of silicon dioxide (SiO2) as the reinforcing phase (5 and 10%) using spin coating method and to investigate the influence of mass concentration of silica particles and process parameters on the morphology and optical properties of the obtained PVP/SiO2 na-nocomposite coatings. The composite layer topography examination, made using atomic force microscope (AFM), showed the increase of roughness due to the increase of silica mass concentration in thin films. UV-Vis spectroscopy analysis showed that with the increase of SiO2 nanoparticles in polymer matrix and use of higher rotation speed, the absorbance level decrease. Besides, composite layers with 10% mass concentration relative to polymer concentration were characterized by wider energy band gap, so it can be concluded that obtained nanocomposite thin films can be used as protective layers against UV radiation, with zero absorption in the range of visible light wavelengths.