多孔含磷氧基聚合物的溶剂热制备及在高酸度下对铀吸附性能的研究

Solvothermal Synthesis of Nanoporous Polymer Adsorbent Bearing Phosphine Oxide for the Removal of Uraniumin Strong Acid Media

研制在高酸度下能有效分离富集铀的吸附介质对我国核工业健康快速发展具有非常重要的意义。以乙烯基膦酸和三羟甲基丙烷三甲基丙烯酸酯为单体,经溶剂热聚合制备了一种新型的多孔含磷氧基聚合物吸附剂,采用多种表征技术对聚合物吸附剂结构及组成进行了分析,研究了溶液酸度、吸附时间、初始浓度、吸附温度对其吸附铀性能的影响。结果表明,吸附剂在高酸度下对铀的吸附行为符合准二级吸附动力学模型和Langmuir等温吸附模型,在4 mol/L硝酸介质中,吸附剂对铀的单分子层饱和吸附容量为255.8 mg/g。聚合物吸附剂对铀的吸附是自发的吸热过程,升高温度有利于吸附。循环使用5次后,吸附剂对铀的吸附容量未见明显降低。

It is of great significance for the rapid development of China's nuclear industry to develop an adsorption medium which can effectively separate uranium from aqueous media at high acidity.A novel phosphine oxygen functionalized nanoporous polymer adsorbent P(TRIM-VPA)was prepared by the solvothermal polymerization of vinyl phosphonic acid(VPA)and trimethylolpropane trimethacrylate(TRIM),which has been characterized by various characterization techniques.Effects of acidity,adsorption time,initial concentration and adsorption temperature on the adsorption properties of uranium were investigated.The results show that the adsorption behavior of polymer adsorbents for uranium is in accordance with the quasi-second-order adsorption kinetic model and Langmuir isothermal adsorption model.In 4 mol/L nitric acid medium,the saturated adsorption capacity of the polymer adsorbent for uranium is 255.8 mg/g.The adsorption of uranium by polymer adsorbents is a spontaneous endothermic process,and the increase of temperature is beneficial to the adsorption of uranium.No significant loss of adsorption capacity of uranium is observed after 5 cycles.