功能高分子膜电极的研制及其对海水中铀的吸脱附过程的研究

发布时间：2018-06-03 23:19

  本文选题：海水提铀 + 功能膜电极　； 参考：《青岛科技大学》2017年硕士论文

【摘要】：本实验采用镍片作为基体材料,在镍片表面进行修饰改性并组装功能高分子复合膜,制备出功能高分子膜电极。首先合成出丙烯腈-乙酸乙烯酯共聚物(P(AN-VAc)),并对其使用醇的碱性溶液进行酯交换反应及羧基化反应制备出带有羟基、羧基的改性共聚物P(AN-VAc-VA-AA)。然后合成出具有一定导电性与强制还原性能的二茂铁基团改性聚氨酯预聚体,通过傅里叶变换红外光谱测试(FT-IR)、核磁共振氢谱测试(1H-NMR)、热重分析测试(TGA)、差示扫描量热法(DSC)对各步骤产物进行分析表征。依次将KH-550、改性聚氨酯预聚体及P(AN-VAc-VA-AA)组装至经预处理的镍片上,然后进行偕胺肟化获得表面带有羧基及偕胺肟基的功能膜电极。使用扫描电子显微镜(SEM)观察膜电极组装过程中各步的表面形貌;使用荧光分光光度法测定了功能膜电极对铀离子的吸附量,并探究了时间、pH条件、吸附温度等条件对功能膜电极吸附性能的影响;使用循环伏安法探究了功能膜电极的电化学行为。(1)合成制备带有羧基的功能高分子,与二茂铁基团改性聚氨酯预聚物同溶于二甲基亚砜(DMSO)中进行组装,最佳组装时间为10 min,在0.01 mol L-1的盐酸羟胺中性溶液中偕胺肟化,最佳反应时间为50 min,可制得功能高分子膜电极。(2)合成具有二茂铁功能基的PU预聚体。二茂铁基团通过α-羟乙基二茂铁(Fc-CHOHCH3)的形式向异氰酸酯中引入:用料量为Fc-CHOHCH3:六亚甲基二异氰酸酯(HDI):三羟甲基丙烷(TMP)=1:3:1(摩尔比),其中α-羟乙基二茂铁由乙酰基二茂铁还原制备最佳条件是0℃下,以FcCOCH3:CuSO4:NaBH4=1:3:3(摩尔比)反应1.6 h;PU预聚体以DMSO做溶剂。(3)使用荧光分光光度法检测吸脱附溶液中铀酰浓度,荧光增强剂用量为2.4%、pH=7时是最佳检测条件。(4)功能电极在常温的中性1μg mL-1的硝酸铀酰标准液中,在8 h左右可以达到平衡吸附量为1.67 mgU g-1的吸附平衡状态,且在室温至35℃区间,随温度升高,吸附达到平衡的速度越快。(5)使用循环伏安法对功能电极进行电化学表征,该功能电极在pH=6.8的磷酸盐缓冲电解质溶液中电化学脱附电压为-1.13 V。(6)功能膜电极在天然海水中进行吸附测试,室温状态下,吸附时间为8h时,吸附容量为1.1 mgU g-1。
[Abstract]:In this experiment, the functional polymer film electrode was prepared by modifying and assembling the functional polymer composite film on the nickel surface. Firstly, acrylonitrile-vinyl acetate copolymers were synthesized, and the modified copolymers with hydroxyl and carboxyl groups were prepared by transesterification and carboxylation of the basic solution of alcohols to prepare the modified copolymers with hydroxyl and carboxyl groups. Then a ferrocene group modified polyurethane prepolymer with certain electrical conductivity and reducibility was synthesized. The products were characterized by Fourier transform infrared spectroscopy (FTIR), 1H-NMR-1H-NMR, TGA and DSC-DSC. KH-550, modified polyurethane prepolymer and P AN-VAc-VA-AA were assembled on the pretreated nickel wafer, and then the functional membrane electrode with carboxyl group and amidoxime group on the surface was obtained by amidoximation. Scanning electron microscopy (SEM) was used to observe the surface morphology of each step in the process of assembling the membrane electrode, and the adsorption amount of uranium ion on the functional membrane electrode was determined by fluorescence spectrophotometry, and the time and pH conditions were investigated. The effect of adsorption temperature on the adsorption performance of functional membrane electrode was studied by cyclic voltammetry. The electrochemical behavior of functional membrane electrode was investigated by using cyclic voltammetry to synthesize functional polymer with carboxyl group. The modified polyurethane prepolymer with ferrocene group was assembled in DMSO (dimethyl sulfoxide). The best assembly time was 10 minutes, and the amidoxime was formed in 0.01 mol L-1 hydroxylamine hydrochloride neutral solution. The pu prepolymer with ferrocene functional group can be synthesized by the best reaction time of 50 min. The ferrocene group is introduced into the isocyanate in the form of 伪 -hydroxyethyl ferrocene (Fc-CHOHCH3): Fc-CHOHCH3: Hexamethyldiisocyanate (HDI): trimethylol propane (TMPP) 1: 3: 1 (mole ratio, where 伪 -hydroxyethyl ferrocene is added by acetyl ferrocene) The optimum preparation condition is 0 鈩，

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