For radiotherapeutic treatment or medical imaging, it is essential that the radioisotope of interest is quickly available in high purity. Therefore, medical radioisotopes are often obtained from a radionuclide generator, which consists of a solid support that acts as an accumulator for the isotope of interest. This project focuses on 225Ac and 213Bi, two isotopes used in targeted alpha therapy. Initially, the mother isotope, 225Ra or 225Ac, is sorbed onto the solid material with high affinity for the cation. Due to radioactive decay, the daughter isotope, resp. 225Ac or 213Bi, accumulates in the material and can be eluted at regular intervals. Currently available solid sorption materials are poorly resistant against radioactive radiation, have a short shelf life and have limited binding capacity. In this project, novel sorption materials that can serve as solid support for 225Ra/225Ac and 225Ac/213Bi generators are synthesized starting from activated carbon or titania particles. Commercially available activated carbon or titania with selected characteristics, such as particle size and porosity, undergo a chemical or heating treatment to modify their surface with a range of chemical functional groups containing oxygen, nitrogen, phosphor or sulphur atoms that can bind cations. Extensive characterization of the modified surface to determine the identity and amount of functional groups and sorption behaviour towards Ra, Ac and Bi in several aquatic media is an important part of the project work. Information gathered by means of various instrumental analytical techniques, such as infrared spectroscopy, thermo gravimetric analysis with mass spectrometry, BET analysis, acid base titration and inductively coupled plasma mass spectrometry allows to understand the surface chemistry of the new materials. In order to evaluate the effect of radioactive radiation on the surface characteristics, promising new material candidates will be irradiated in an-house facility, followed by reassessment of surface and sorption characteristics. Most promising materials will undergo a shaping process in the form of controlled coagulation to produce uniform sorption materials with good packing and elution characteristics. After final validation of the material for the intended application, a new radionuclide generator sorption material is available. It will be well shaped, well characterized, radiation resistant, with sufficient binding capacity and separation chemistry.