RADIOLABELING OF POLYSTYRENE BY GAMMA-RAY IRRADIATION IN THE PRESENCEOF 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 up on gamma-ray irradiation to form I-2 molecules, which formed charge tr ansfer complex with polystyrene. The complex formation was confirmed w ith VV and vis spectrophotometry. The spectrum of polystyrene film irr adiated in the presence of NaI aqueous solution was similar to that of the polystyrene film forming charge transfer complex with I-2 molecul es 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 m olecules form CT complex with benzene ring of the polystyrene by gamma -ray irradiation. The stability of the complex was studied in phosphat e buffered saline solution, alcohol and mouse peritoneal cavity.