Preparation Of The Novel Calix[4]crown-5 Functional Materials For Cs/Rb Adsorption

137Cs,one of the heat emitting nuclides,is a key radionuclide with a half-life of 30.1 yr in high-level liquid waste(HLLW).It has a potential and long-termed risk in safe geological disposal of HLLW.It poses a danger to the safety of the geological repository,and has a negative impact on the nuclear fuel cycle and the sustainable development of nuclear energy.The efficient separation of 137Cs from HLLW therefore has been one of the challenging works that have been unsolved frontier issues.It is well known that HLLW is an extremly complicated system with high HNO3 concentration around 3.0 M,strong radioactivity and complex chemical composition.The selection of new materials,simple and effectively new methods is an effective pathway for 137Cs separation from HLLW.For this purpose,a new polymer based Calix[4]crown-5 supramolecular recognition material for the adsorption and separation of Cs from Rb-containing effluent in simulated HLLW were investigated.A novel pathway for the effective separation of Cs and Rb has been achived.The main results are as follows:1.A few Calix[4]crown-5 compounds,BCalixC5,BnPCalixC5,BiPCalixC5 and BnBCalixC5,were synthesized.The corresponding composition and structure were characterized by SEM,elemental analysis,TG-DSC,ESI-MS and XRD.2.New polymer-based supramolecular recognition materials,BCalixC5X,BnPCalixC5X,BiPCalixC5X and BnBCalixC5X were prepared using mesoporous XAD-7 as the carrier.The morphology,physicochemical parameters,thermal stability and other composition and structural properties were characterized using SEM,N2 adsorption-desorption isotherm,XRD and TG-DSC.3.The adsorption of Rb,Cs and other typical metals towards the materials in HNO3 medium were investigated.It was performed by examing the influence of HNO3 concentration(0.4-6.0 M),contact time and temperature(298-318 K).The results show that the materials have excellent adsorption ability and selectivity for Rb over Cs and others.In these studies,BiPCalixC5X has high separation coefficient of 186.5 for Rb/Cs in 1.0-2.0 M HNO3 at 298 K.It is promising to application of BiPCalixC5X in effective separation of Cs and Rb.