Enrichment Of Trace Pt(?),Pd(?),Au(?) In Aqueous Solution By Imidazolium Polymer Ionic Liquids

Two different types of polymer ionic liquids were synthesized and used as solid extractants to study the adsorption of trace concentrations of Pt(IV),Pd(II)and Au(III)in aqueous solution.A series of factors that influence the adsorption process were discussed.Finally,the possible adsorption mechanism was presumed by characterization of the metal-loaded adsorbents by various means.Compared with the traditional recovery and enrichment methods,this method has the advantages of strong selectivity and good recyclability.The paper mainly contains the following sections:1.The main properties of precious metals,especially gold,platinum and palladium,and their extensive application in many fields are described in the introduction,and the disposal methods of primary and secondary resources of precious metals are introduced.According to the characteristics of ionic liquids and polymer ionic liquids,the application examples of this new type of polymeric materials in recycling metals are summarized.Additionly,the basis and practical significance of this thesis are put forward.2.[PS-PVBC-Nim]Cl as a linear polymer ionic liquid was obtained by grafting modification of styrene(St)and ?-chloromethylstyrene(VBC)with N-methylimidazole.The effects of various factors,such as HCl concentration,mass of ionic liquids,temperature,time,and coexisting metal ions on the enrichment processes of Pt(IV)and Pd(II)were discussed.At the same time,the adsorption kinetics and thermodynamics were evaluated.Finally,the metal-loaded ionic liquids were characterized by FTIR,TG,SEM,XPS and EDS.The results show that the PIL has good cycling and excellent selectivity in binary systems.3.The crosslinked polymer ionic liquid [PAN-PVBC-amino]Cl was synthesized by using basic chemical raw materials(AN)and N-(3-aminopropyl)-imidazole instead of styrene(St)and N-methylimidazole respectively.Then it's structure was analyzed by EA,FTIR,XRD,SEM.The optimal adsorption conditions for Pt(IV),Pd(II)and Au(III)were determined by univariate experiments.Moreover,the adsorption kinetics and thermodynamics were researched.In the end,metal-loaded ionic liquids were characterized by a series of analytical methods.The experimental results show that the adsorption capacity of [PAN-PVBC-amino]Cl is relatively larger while maintaining high selectivity and excellent cycle performance.