Synthesis, characterization and study of optical properties of polyvinyl alcohol/CaF2 nanocomposite films

CaF2 Nanoparticles (NPs) were synthesized with a co-precipitation method and used in the preparation series (Polyvinyl Alcohol (PVA)/CaF2 nanocomposite films) with different amounts of CaF2 NPs. The synthesized NPs and nanocomposite films were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), UV-Vis spectroscopy and Photoluminescence (PL) techniques. The XRD results indicate the formation of CaF2 NPs with THE Cubic phase and the crystalline size is estimated using Scherrerʹs to be in the range 2027 nm. SEM images of nanocomposite films show CaF2 NPs were uniformly distributed on the PVA film surface. The optical absorption spectrum shows a strong absorption edge at about 300 nm. The NPs PL spectrum shows a series of emission peaks at 394 and 790 nm, and the PL band of PVA/CaF2 films attribute to n  electronic transition in non-bonding 2p2.O/ electrons in free OH groups in three (syndiotactic, atactic, and isotactic) conformers of PVA polymer molecules.