Electroless sliver-plating process in the preparation of ¹⁰³Pd-¹²⁵I hybrid brachytherapy seed cores

Electroless ^l03Pd plating and electroless Ag plating and chemical ¹²⁵I depositing were took place on the surface of carbon rods in turn, which was a reliable method for the preparation of ¹⁰³Pd-¹²⁵I hybrid brachytherapy seed cores. ¹⁰³Pd and ¹²⁵I were deposited on the same substrate effectively through silver coating as a bridge. The process of electroless Ag plating was a novel and important step in the preparation of ¹⁰³Pd-¹²⁵I hybrid seed. In this work, the process of electroless Ag plating was studied using ø0.5 × 3.0 mm carbon rods with palladium coating as substrate, silver-ammino complex as precursor, ^110mAg as radioactive tracer, and hydrazine as reductant. The optimum conditions were AgNO₃ 2g/L, Na₂EDTA40 g/L, NH₃·H₂0 16.25%, H₄N₂·H₂0 5‰, pH = 10, t = 60 min, and T = 35 ℃. Sliver deposited on each carbon rod was uniform, and sliver-coating was white and smooth. (authors)