Synthesis Of Oxadiazole-functionalized Polyacrylonitrile Fiber And The Absorption For Hg²⁺

In this thesis,six kinds of 1,3,4-oxadiazole derivatives were immobilized to the propylenediamine-aminated fiber by Mannich reaction.The functionalized fibers were used to absorb mercury ions.The functionalized fibers combine the advantages of polyacrylonitrile fiber and 1,3,4-oxadiazole derivatives together.The main research contents are summarized as follows:1.A series of 1,3,4-oxadiazole derivatives were prepared by different methods.Then,with polyacrylonitrile fiber as raw material,propylenediamine was introduced to the fiber to obtain the aminated fiber（PAN_p F）.Six kinds of 1,3,4-oxadiazole functionalized fibers were prepared by immobilizing 1,3,4-oxadiazole to the aminated fiber.The successful immobilization of 1,3,4-oxadiazole derivatives to the aminated fiber was supported by IR,EA,SEM and XRD.2.The functionalized fibers were used to absorb mercury ions.The results indicate that the PAN_p-PMODF fiber had the best absortion capacity and was selected for further research.The absorption performance of PAN_p-PMODF was systematically studied.The effects of p H value of mercury ion solution,the initial concentration of mercury ions and the adsorption time on the adsorption performance of PAN_p-PMODF were investigated.The results showed that PAN_p-PMODF had a good absorption capacity in the mercury ion solution over a wide pH range from 4 to 12.The absorption kinetics of PAN_p-PMODF suggested that the absorption process of PAN_p-PMODF for mercury ion is chemisorption.The isothermal absorption indicated that the absorption process of PAN_p-PMODF for mercury ion is monolayer absorption.The PAN_p-PMODF showed good selectivity for mercury ion in a mixed solution of heavy metal ions(including Hg²⁺,Pb²⁺,Ni²⁺,Zn²⁺,Ag⁺,Cr³⁺,Co²⁺,Cu²⁺and Cd²⁺).PAN_p-PMODF exhibited good recyclability（more than five times）by desorbing mercury ions completely in dilute HNO₃ solution.In summary,easy availability,low cost,good selectivity and reusability,and simple operations make the fiber attractive for the treatment of mercury ion in polution.