Study On The Adsorption Materials Prepared By Radiation Technology And Their Adsorption Properties

With the rapid development of nuclear power in China,the shortage of uranium resources has caused people to shift their research focus to the development of unconventional uranium resources.At the same time,the pollution problem of nuclear waste represented by volatile iodine also needs to be solved immediately.The adsorption method is an effective way to deal with the above two problems.The core of this method lies in polymer-based functional adsorption materials.Radiation grafting technology is a promising method for polymer functionalization.This paper uses radiation grafting technology to functionally modify polyethylene-coated polypropylene-core（PE/PP）fiber and biaxially stretched polyethylene（BSPE）membranes.PE/PP-g-PNVP fibers for the adsorption of iodine and.PAO-BSPE..membranes for uranium extraction from seawater were successfully prepared.The main contents and analysis results are as follows:（1）The preparation of PE/PP-g-PNVP fibrous adsorbent and its adsorption performance for iodine.The one-step reaction co-radiation grafting technique was employed in the graft polymerization of N-vinyl-2-pyrrolidone（NVP）onto polyethylene-coated polypropylene skin–core（PE/PP）fibers through electron beam（EB）irradiation,and the PE/PP-g-PNVP iodine fibrous adsorbent were successfully prepared.FT-IR,SEM,TGA and XPS were utilized to characterize the chemical structure,surface morphology and thermal stability of the PE/PP fibers before and after the modification.The iodine adsorption capacity of the PE/PP-g-PNVP fibers was1237.8 mg/g.What’s more,these fibrous absorbents can be efficiently regenerated by two different ways of ethanol elution and heating at 120 ^oC,respectively.The enhancement of the adsorption capacity and the long service life of at least ten adsorption–desorption cycles suggest that this kind of fibrous adsorbent has good adsorption performance for volatile iodine with a long service life.（2）The preparation of PAO-BSPE membrane adsorbent and study on its adsorption performance for uranium.Based on the interface self-assembly of the axial grafting chains,a two-step grafting polymerization method of radiation grafting combined with chemical grafting was used to successfully synthesize a new functional BSPE membrane materials modified with amidoxime groups,which was named as PAO-BSPE membrane.The results of FT-IR,SEM-EDS,BET and contact angle showed that the modified membrane exhibited excellent hydrophilicity,good mechanical properties,high specific surface area,and confirmed the formation of mesopores architecture and nanochannels.In the simulated seawater adsorption experiment,it can efficiently uranium adsorption in the presence of high concentrations of Mg²⁺,Ca²⁺and HCO₃^-and other competing ions.The distribution coefficient（K_d）reached7.3×10⁴m L/g,and a low degree of grafting resulted in a relatively high uranium adsorption capacity of 10.71 mg-U/g–ads.At least 12 cycles of the service life of the adsorbents were obtained,showing the good selective adsorption performance for uranium extraction from seawater with a long repeated service life.