Preparation Of Rare Earth Element Sm Solid Phase Separation Adsorbent

Samarium is a kind of lanthanide element,which has abundant physical and chemical properties.Because of its unique properties,samarium has been widely used in the research and preparation of optical?electrical?magnetic?nuclear and other functional materials.In the process of the preparation and development of functional materials,a large number of high-purity samarium elements are particularly needed.There are various ways of separation for the rare earth elements,and one of the most effective methods of separation and enrichment is Solid Phase Extraction(SPE).The SPE with many advantages,such as splendid selectivity,expedient process,less demanding of solvent and high enrichment efficiency,has become a commonly used rare earch separation technology.The selection of the adsorption material is the most important factor of SPE,which has a direct relationship with the performance of solid phase extraction.The solid phase extraction has a wide range of base materials,including silica gel.Because of its large specific surface area,easy modification,strong corrosion resistance and excellent chemical properties,silica gel has become a potential kind of SPE base material,meanwhile,its non-toxic and cheap characteristic is also the important reason being widely used.Nevertheless,the slica gel as SPE substrate does not meet the needs of the selectivity for experiments or production,which is necessary to be further modified.The main method is to modify the silica gel with chelating ligand,which can significantly improve the adsorption performance.Therefore,it's the key for SPE to select the chelating ligand with the selectivity of Sm.The main idea of the dissertation is:selecting ligands with selective coordination ability of Sm;and preparing several kinds of metal organic framework materials by the synthesis of mixed rare earth elements,as well as the using hydrothermal or solvothermal method;Then,analyze the change of ion concentration in the solution before and after the reaction by inductively coupled plasma atomic emission spectrometry(ICP-AES),on the purpose of judging whether the product is a single metal coordination polymer.At last,analyzing the structure by X-ray diffraction to obtain the phase purity and the heat endurance.On this basis,loading the silicone with the ligand of coordination selectivity,and conducting an investigation on the adsorption properties of Sm by the detecting instrument,ICP-AES,in the meantime,researching on the related factors affecting the enrichment.Finally,studying the selectivity of solid-phase extraction material to the lanthanide elements.According to the idea,this paper mainly studies several aspects:1)Synthesis and properties of ligands and metal organic frameworksLigands H2mmtdc,H6La,tpib,H4pztc and a series of 4,5-imidazole-1,10 phenanthroline compounds was synthesized.We used these ligands to react with mixed rare earth metal ions to bulid rare earth coordination polymers.By measuring the selectivity of ligands,we got the result that H2mmtdc,H6La,tpib and H2bdim ligands had the coordination selectivity.The crystal structure of the coordination polymers were studied by using the X-ray diffraction analysis.The results showed that the ligands H2mmtdc,H6La,tipib and H2bdim in the presence of mixed rare earth metal ions only coordinated with Sm to form coordination polymers.The selectivity of the ligands were also proved.2)The study of the solid phase extraction performance of silica gel which was loaded by H2mmtdc,H6La,tipib and H2bdim ligandsThe optimum enrichment conditions and influencing factors of silica gel which was loaded by H2mmtdc,H6La,tipib and H2bdim ligands were studied.The results showed that in the conditions of 3,5,5 and 4 in pH;the shock time were 20,15,5,25 min;flow rate were 1.5,1,2,2 mL min-1,the adsorption capacity of solid phase extraction material 1-4 was the best.The adsorbent can be quantitatively eluted by using 4 mL mol L-1,2 mL 1.5 mol L-1,1.5 mL 1.5 mol L-1and 2.5 mL 1 mol L-1 nitric acid solution.The enrichment times of solid phase extraction material 1-4 were 50,100,100,and 20,respectively.Solid phase extraction material 1-4 had good separation effect on Pr3+/Sm3+ and Eu3+/Sm3+,Nd3+/Sm3+ and Eu3+/Sm3+,Pr3+/Sm3+ and Nd3+/Sm3+,Ce3+/Sm3+ ion pairs,respectively.