Preparation Of Amidoxime-based Polyacrylonitrile Fibers By Wet Spinning And Its Adsorption Properties For Uranyl Ion

In order to achieve sustainable energy development,all countries in the world regard nuclear energy as their main energy development goal.However,with the development of the nuclear energy industry,it is inevitable that a large amount of uranium-containing waste liquid will be produced in the process of nuclear power operation,in the nuclear fuel cycle and the post-treatment of spent fuel.Therefore,how to deal with these waste liquids quickly and effectively is of great significance.In this paper,a homogeneous method was used to prepare amidoxime-based polyacrylonitrile(PAN),dimethyl sulfoxide(DMSO)as an organic solvent to dissolve hydroxylamine hydrochloride,and the mixture was reacted with polyacrylonitrile powder.The pure polyacrylonitrile is mixed in a certain ratio,and a certain amount of the pore-forming agent polyvinylpyrrolidone(PVP)is added to prepare the amidoxime polyacrylonitrile fiber by a wet spinning process.The prepared adsorbent was characterized by Fourier transform infrared spectroscopy(FT-IR),fiber strength test,scanning electron microscope(SEM)and specific surface area and pore size analyzer.The adsorption performance of the adsorbent on uranyl ions was studied by using uranyl nitrate solution with an initial concentration of 100 ppm.The effects of pH,adsorption time and adsorption temperature on the adsorption of uranium solution were investigated.The material characterization results show that the nitrile group(-C?N)in the PAN powder has reacted with hydroxylamine hydrochloride(NH2OH�HCl)to produce a new functional group:amidoxime(-C(=NOH)NH2),and The fibers prepared by the wet spinning process still have this functional group.The PAO fibers prepared by wet spinning have the properties of commercially available fibers and have a certain mechanical strength.At the same time,the addition of the pore-forming agent increases the roughness of the fiber surface,forming a lot of micropores and grooves,and increasing the specific surface area of the fiber to 9.7299 m2/g.The adsorption experiment results show that the optimal adsorption capacity of PAO fiber is 58.16mg/g,which is much higher than 5.44mg/g of PAN fiber.The quasi-secondary dynamics model,the yelovic model and the liquid membrane diffusion model were used to fit the kinetics of the adsorption process.The quasi-secondary kinetic model and the liquid membrane diffusion model can explain the adsorption process well.In the thermodynamics part,the Friedrich model and the Langmuir model were selected for fitting,and the adsorption process was most fitted to the Langmuir model.