Radiation techniques are used to modify the physical, chemical and biological properties of polymers. This induces crosslinking and degradation reactions of polymers by utilizing radicals generated through ionizing radiation. However, oxidation products (such as carbonyl) can be formed because oxidation occurs by chain scission in the presence of oxygen. Herein, we demonstrate the gamma-ray irradiation-induced oxidation with and without fluorine using polyethylene, polyvinylidene fluoride and polytetrafluoroethylene under the same conditions. In this study, changes in element-content and chemical-bond structures were analyzed before and after gamma-ray irradiation under air atmosphere. As a result, polytetrafluo-roethylene showed less oxidation and excellent thermal properties after the absorbed dose of 500 kGy. This can be attributed to the generation of stable perfluoroalkylperoxy radicals after gamma ray irradiation in the PTFE structure containing only CF₂ groups, thereby hindering the oxidation reaction.

We report column material for a ⁶⁸Ge/⁶⁸Ga generator with acid resistance and excellent adsorption and desorption capacity of ⁶⁸Ge and ⁶⁸Ga, respectively. Despite being a core element of the ⁶⁸Ge/⁶⁸Ga generator system, research on this has been insufficient. Therefore, we synthesized a low molecular chitosan-based TiO₂ (LC-TiO₂) adsorbent via a physical trapping method as a durable ⁶⁸Ge/⁶⁸Ga generator column material. The adsorption/desorption studies exhibited a higher separation factor of ⁶⁸Ge/⁶⁸Ga in the concentration range of HCl examined (0.01 M to 1.0 M). The prepared LC-TiO₂ adsorbent showed acid resistance capabilities with >93% of ⁶⁸Ga elution yield and 1.6 × 10⁻⁴% of ⁶⁸Ge breakthrough. In particular, the labeling efficiency of DOTA and NOTA, by using the generator eluted ⁶⁸Ga, was quite encouraging and confirmed to be 99.65 and 99.69%, respectively. Accordingly, the resulting behavior of LC-TiO₂ towards ⁶⁸Ge/⁶⁸Ga adsorption/desorption capacity and stability with aqueous HCl exhibited a high potential for ion-exchange solid-phase extraction for the ⁶⁸Ge/⁶⁸Ga generator column material.

The outstanding electrical, mechanical, and thermal properties of carbon nanotubes (CNTs) make them promising materials for a wide range of applications. Numerous theoretical and experimental studies on the diameter-dependent properties of single-walled carbon nanotubes (SW-CNTs) exist. The incorporation of carbon nanotubes into commercial polymers can alter the properties of both materials. Herein, we demonstrate polystyrene/SW-CNT composites with different diameters to check property changes, including radiation-protective characteristics under various doses of gamma radiation. The intrinsic glassy state of polystyrene disappeared owing to the introduction of SW-CNTs into the polymer-polymer chain. In addition, when 1.3 nm diameter SW-CNTs were introduced, the Fourier-transform infrared spectroscopy peaks for alkyl aryl ethers were observed at 10–60 kGy of gamma irradiation. In this study, the different phenomena that occur when polystyrene/SW-CNT composites are formed with different SW-CNT diameters (0.78 nm and 1.3 nm) were investigated via systematic analyses.