Synthesis Of Functional Polymer Film And Study On The Process Of Adsorption/ Desorption Of Uranium From Seawater

In order to improve the efficiency of adsorbing uranium from seawater, an chelating electrode with functional film was prepared. Nickel plate was the substrate. KH-550, Polyurethane(PU) prepolymer and P(AN-co-AA) were coated on the nickel substrate by self-assembly in turn. There are some ferrocene groups were grafted on PU prepolymer. Finally, the film electrodes were placed in hydroxylamine hydrochloride solution directly to make functional electrodes which contained amidoxime groups. The product of each step was characterized by FT-IR and 1H NMR. The surface morphology of the electrodes was characterized by SEM. The electrochemical behavior of the functional electrode was discussed by cyclic voltammetry, and the uranium content was determined by fluorescence spectrometry.(1) The film electrodes were prepared by the self-assembly process. According to the conductivity values, the best volume ratio of the KH-550, C2H5OH and H2O was 1:74:25. The optimal hydrolysis time was about 30min at 25℃. The optimal assembly time in KH550 solution and PU prepolymer/ethyl acetate was 2min,10min respectively. While the mass ratio of acrylic acid and acrylonitrile was 1:9, the optimal assembly time in P(AA-co-AN)/DMF was 7min.The film electrodes were prepred successfully.(2) The film electrodes were placed in hydroxylamine hydrochloride solution. And then the cyano groups were converted to amidoxime groups. The optimal reaction time was determined by SEM characterization, and the best time was 50min. Finally, the functional electrodes were prepared successfully.(3) The functional electrodes were placed in seawater to adsorb uranium. The adsorption rate varied with the extension of the adsorption time and stir. The maximum adsorption capacity was obtained after 8 days,and the adsorption capacity was 6.3mg/g adsorbent.(4) The surface morphology of the electrodes was characterized by SEM. The electrodes had a great change after adsorption uranium. The effect of adsorption was well.(5) 3% NaCl solution and phosphate buffer(pH=6.8) could be used as the supporting electrolyte.Testing the cyclic voltammetry behavior of the functional electrodes which had adsorbed uranium in natural seawater. The desorption voltages were 0.25V and 0.72V, respectively.