Study On The Structure Construction Of Functional Polymer Membrane And Its Adsorption And Desorption Process For Uranium In Water

In this experiment, the nickel plate was used as the substrate to assemble the functional polymer composite film on the surface of t he nickel sheet. First,we synthesized ferrocene modified polyurethane(PU) prepolymer, graphene / PU prepolymer composite and PAN-GMA copolymer, then treated PAN-GMA by ammonolysis. Products in different stages of the synthetic were characterized by FTIR, 1H NMR, TGA, DSC. KH-550, PU prepolymer and PAN-GMA ammonolysis products were coated on the treated nickel substrate by self-assembly in turn, then transform the cyano to amidoxime. Finally we obtained the functional electrode with amino and amidoxime.The adsorption capacity o f the functional electrode was determined by fluorescence spectrophotometry, and the effect of time, pH and temperature on the adsorption capacity of functional electrode is studied.(1) Synthesizing α-hydroxyethyl ferrocene for the preparation of ferrocene modified PU prepolymer. α-hydroxyethyl ferrocene was prepared by reducing acetylferrocene, the best reduction system for this reaction was FcCOCH3: CuSO4:NaBH4=1:3:3(mole ratio). The reaction time is 1.5 h, the yield is up to 87%.(2) The optimal assembly time of nickel plate with KH-550 in ferrocene modified PU prepolymer/ethyl acetate was 15 min. The optimal assembly time of nickel plate with KH-550 in graphene composite PU prepolymer/NMP was 15 min. The optimal assembly time in PAN-GMA ammonolysis products/NMP was 10 min. The optimal reaction time in 0.01 mol/L hydroxylamine hydrochloride is 50 min.(3) Fluorescence spectrophotometry was used for measuring the concentration of uranium ion, the best concentration of fluorescence-enhancing agent was 2.4%, and the best p H was 7. At room temperature, p H=7 condition, the adsorption equilibrium of functional electrode in 1 μg/mL uranyl nitrate solution by static adsorption was 1.6 mgU/gAdsorbent, adsorption equilibrium time was 8 h. The optimal pH of adsorption was 6. The equilibrium adsorption capacity of functional electrode is improved with the elevating of temperature in the range of 20-35℃.(4) According to the test of cyclic voltammetry, it is known that the desorption voltage of ferrocene modified functional electrode and graphite composite functional electrode in p H=6.8 phosphate buffer are both-1.2V.