The impact of synthesis conditions on the structure and the radionuclide adsorption capacity of silylated clay minerals was evaluated in this study. Two green solvents were selected in this work, phenoxypropanol and glycerol, and various synthesis temperatures (30, 60 and 90 degrees C) were tested for the preparation of 3-aminopropyltriethoxysilane (APTES)-functionalized Laponites. The resulting adsorbents exhibit various extent and location of the grafting reaction as a function of the used solvent and temperature. These modifications of the reactivity of the materials also impact adsorption and desorption properties of Co2+ and Sr2+. However, the two ions are well adsorbed whatever the synthesis conditions, and even in bisolute experiments, the adsorption capacity is not systematically proportional to the amount of loaded APTES, highlighting the specific impact of the synthesis conditions. Finally, the very limited desorption in saline solutions suggests that the synthesized adsorbents display suitable properties for the removal of radionuclides from aqueous solutions.