Mohammed, A. AliOmer, MEM, Gar-elnabi, Alyaa, H. Ahmed, Ghada Abaker Eidam, Nasr Aldeen N. Khidir
Abstract: The PVA bulk solution was first prepared by dissolving PVA powder (5 wt %) in distilled water under controlling water bath temperature at 60-70 0C and continuous stirring for 3 hours, After the solution cooled down to ambient temperature, a concentration of (0.01and 0.03 wt %) of AgNO3 were added to solution in a darkroom and stirred for 2 hours, then the blend solution is poured into Petri dishes and allowed to dry to form films by casting under ambient temperature for 3 days in a darkroom, after draying the films were cut to 2cmx2cm and kept in black pags. The films were exposed to different doses (2, 4, 6, 8, 10 Gy) from a linear accelerator by constant energy 6 MeV with applicator cone and SSD (applicator surface distance) 50 cm, field size 10cmx10 cm. The characterization by by UV-visible spectroscopy showed that the pure PVA has an absorption peak in the range of ultraviolet at 275 nm and the absorption peak increases with radiation dose increment from 0 to 10 Gy and the composites films (PVAAgNO3) showed an absorption peak coefficient at 420 nm (visible light) which is also increases as the radiation dose increases. Also the energy band gap of the composites irradiated films appeared to be decreases from 4.0E-19 down to 3.5E-19 eV. Moreover the optical density of the irradiated films showed significant correlation (R2 = 0.99) with the applied dose. While the tensile strength (TS) of the irradiated PVA film has been increases following the increment of radiation dose and peaking at 30 MPa at 6 Gy, then decreases as the dose increase. The study also revealed that there is a significant (R2 =96) linear proportional relationship between the absorption coefficient and the applied dose on the PVA film.
Keywords: Polymer, films, Radiation, Processing