Diffusion and Sorption of Radium and Strontium in a Layer of Porous Sorbent Based on Hydroxyapatite

A cell for studying the diffusion of therapeutic medical radionuclides into the macrolayer of the carrier sorbent was fabricated using 3D printing. The diffusion of ultramicroquantities of radium and strontium within a layer of watered hydroxyapatite was investigated. The value of the effective diffusion coefficient obtained using a one-dimensional nonstationary model was (1.0 ± 0.4) × 10 –8 cm 2 /s for Ra and (3.0 ± 0.3) × 10 –8 cm 2 /s for Sr.