RADIOLABELING OF POLYSTYRENE BY GAMMA-RAY IRRADIATION IN THE PRESENCE OF NA I-125 SOLUTION

The radiolabeling of polystyrene microsphere and film was carried out by gamma-ray irradiation under immersion in Na I-125 aqueous solution. It was found that radiolysis of Na I-125 aqueous solution occurred upon gamma-ray irradiation to form I-2 molecules, which formed charge transfer complex with polystyrene. The complex formation was confirmed with VV and vis spectrophotometry. The spectrum of polystyrene film irradiated in the presence of NaI aqueous solution was similar to that of the polystyrene film forming charge transfer complex with I-2 molecules in gas phase and its lambda(max) value was almost the same as that of the complex between I-2 and benzene, indicating that produced I-2 molecules form CT complex with benzene ring of the polystyrene by gamma-ray irradiation. The stability of the complex was studied in phosphate buffered saline solution, alcohol and mouse peritoneal cavity.