【作者】 王楠；

【导师】 赵龙；

【作者基本信息】 华中科技大学 ， 化学， 2023， 硕士

【摘要】 在核电运行过程中会产生大量的乏燃料,锝（Tc）因具有裂变产率高、半衰期长和迁移率高等特点,相比于其他放射性核素,更容易进入到环境中危害生态平衡,而成为乏燃料后处理中最受关注核素之一。由于Tc具有放射性,在常规实验室无法对其研究,人们通常用与它具有相似性质的铼（Re）进行代替。同时,Re也是一种稀有金属,广泛应用于航空航天,化学化工等领域中,因此,对Re的研究也具有及其重要的意义。本研究通过辐射接枝方法将离子液体固载到纳米二氧化硅上,得到一种新型纳米吸附材料,将其应用于Re的去除。（1）通过原位法合成烷基化纳米二氧化硅,采用辐射接枝方法将1-乙烯基-3-乙基咪唑溴盐离子液体（[C₂VIm]Br）固载到纳米硅基基材上,制备一种纳米二氧化硅吸附材料（S-Si-MPTS-IL）。通过FTIR、SEM和TGA对S-Si-MPTS-IL进行表征。通过批量吸附实验研究了吸附材料对Re（Ⅶ）的吸附性能。S-Si-MPTS-IL对Re（Ⅶ）表现出快速的吸附动力学,最大吸附量可达到131.41 mg/g。（2）通过后改性法制得纳米二氧化硅基材,然后对其进行烷基化处理,最后通过辐射接枝方法将[C₂VIm]Br固载到烷基化纳米二氧化硅上,制得P-Si-MPTS-IL吸附材料。P-Si-MPTS-IL具有开放的介孔结构和较高的比表面积,对Re（Ⅶ）表现出快速的吸附动力学和高效的吸附性能,最大吸附量为141.04 mg/g。在多种共存阳离子存在下,P-Si-MPTS-IL可以对Re（Ⅶ）进行选择性吸附。此外,P-Si-MPTS-IL还具有良好的循环稳定性和耐辐照稳定性。（3）采用溶胶-凝胶法制得核壳式磁性纳米二氧化硅,通过电子束辐照技术在烷基化磁性纳米二氧化硅上接枝1-乙烯基-3-辛基咪唑溴盐（[C₈VIm]Br）得到新型磁性纳米二氧化硅吸附材料。该吸附材料对Re（Ⅶ）的最大吸附容量为62.04 mg/g,在大量阴离子存在的情况下具有良好的选择性。经过5次循环使用,其吸附性能几乎不变化,可在外磁场作用下进行回收再利用。更多还原

【Abstract】 A large amount of spent fuel is produced during nuclear power operation.Technetium（Tc）is more likely to enter the environment and harm the ecological balance compared with other radionuclides because of its high fission yield,long half-life and high mobility.Therefore,it has become the most concerned nuclide in the reprocessing of spent fuel.Because Tc is radioactive and cannot be studied in conventional laboratories,rhenium（Re）,which is similar to Tc,is usually used instead.At the same time,Re is also a rare metal,widely used in aerospace,chemical and other fields,therefore,the study of Re is also of great significance.In this study,a new type of nano-adsorbent material was obtained by means of radiation grafting of ionic liquid onto nano-silica,which was applied to the removal of Re.（1）A kind of nano-silica adsorption material（S-Si-MPTS-IL）was prepared by in situ synthesis of alkylated nano-silica,and 1-vinyl-3-ethyl imidazolium bromide ionic liquid（[C₂VIm]Br）was supported on nano-silica substrate by radiation grafting method.S-Si-MPTS-IL was characterized by FTIR,SEM and TGA.The adsorption properties of Re（Ⅶ）were studied by batch adsorption experiments.The adsorption capacity of S-Si-MPTS-IL to Re（Ⅶ）was high and the maximum adsorption capacity was up to 131.41 mg/g.（2）The nano-silica substrate was modified by post-modification method,and then it was alkylated.P-Si-MPTS-IL adsorption material was prepared by the radiation grafting of[C₂VIm]Br onto the alkylated nano-silicon dioxide.P-Si-MPTS-IL had open mesoporous structure and high specific surface area.It exhibited rapid adsorption kinetics and high adsorption capacity for Re（Ⅶ）,with the maximum adsorption capacity of 141.04 mg/g.P-Si-MPTS-IL could selectively adsorb Re（Ⅶ）in the presence of multiple cations.In addition,it also showed good cyclic stability and radiation resistance.（3）Core-shell magnetic nano silica was prepared by sol-gel method.A novel magnetic nano-silica adsorbent was prepared by grafting 1-vinyl-3-octylimidazole bromide（[C₈VIm]Br）onto the alkylated magnetic nano-silica by electron beam irradiation technique.The maximum adsorption capacity of the adsorptive material for Re（Ⅶ）was 62.04 mg/g.It showed good selectivity in the presence of a large number of anions.After 5 cycles of use,its adsorption performance almost unchanged,and could be recycled.更多还原