新型铋基SiOCNF复合膜对放射性气态碘的吸附性能

Adsorption Properties of Novel Bismuth-based SiOCNF Composite Membrane for Radioactive Gaseous Iodine

放射性碘是典型的核裂变产物之一,吸附-分离-固化放射性碘(^(129)I、^(131)I等)对于核电运营、乏燃料后处理具有重要意义。本研究采用静电纺丝技术和热还原方法,以一种聚甲基倍半硅氧烷树脂(MK树脂)为原料,成功制备出一种新型铋基复合纳米纤维膜(Bi@SiOCNF)。该材料以SiOC纤维为基体,金属单质铋负载在SiOCNF表面与三维网络空间,对气体碘表现出良好的捕获与固定能力。吸附实验结果表明,该材料在2 h内可达到最大饱和吸附容量(515.2 mg/g)。XRD、XPS等测试结果表明,铋基SiOCNF复合纳米纤维膜通过化学吸附与物理吸附机制共同吸附气态碘。热分析表明,Bi@SiOCNF具有良好的热稳定性。该材料在核电站、乏燃料后处理厂对放射性气态碘的捕获、固定和储存等方面具有潜在的应用前景。

Radioactive iodine is one of the typical nuclear fission products.As a result,adsorption-separationsolidification of radioactive iodine(^(129)I,^(131)I,etc.)is important for nuclear power operations and spent fuel reprocessing.In this study,a novel type of bismuth-based composite nanofiber membrane(Bi@SiOCNF)was prepared by thermal reduction and electro-spinning technology using a kind of commercial poly-thylsilsesquioxane resin(MK resin)as raw material.Based on SiOC fiber,the bismuth metal was uniformly loaded on the surface of SiOCNF and in the three-dimensional network space,showing excellent capability for capturing and immobilizing gaseous iodine.According to the adsorption experiment results,the material can reach the maximum saturated adsorption capacity as high as 515.2 mg/g within 2 h.Adsorption mechanism of gaseous iodine on bismuth-based SiOCNF composite nanofiber membrane was through chemical adsorption and physical adsorption which was verified by XRD,XPS and other tests.Thermogravimetry analysis(TGA)demonstrated that the Bi@SiOCNF owned an excellent thermal stability.All above properties indicate that the material has potential applications in the capturing,fixation and storage of radioactive gaseous iodine in nuclear power plants and spent fuel reprocessing plants.