联苯甲酰桥联β-环糊精吸附U(Ⅵ)的动力学和热力学（英文）  

Kinetics and Thermodynamics of Adsorption of Benzil-Bridgedβ-Cyclodextrin on Uranium(Ⅵ)

作　　者：荆鹏飞[1] 刘慧君[1] 张勤[1] 胡胜勇[1] 雷兰林 冯志远[1] 

机构地区：[1]南华大学化学化工学院,湖南衡阳421001

出　　处：《物理化学学报》2016年第8期1933-1940,共8页Acta Physico-Chimica Sinica

基　　金：supported by the National Natural Science Foundation of China(11375084);Hunan Provincial Innovation Foundation for Postgraduate,China(CX2015B399)~~

摘　　要：β-环糊精与对甲苯磺酰氯在低温碱性溶液中反应合成6-对甲苯磺酰酯-β-环糊精,并利用红外光谱和核磁共振氢谱对其进行表征;联苯甲酰与6-对甲苯磺酰酯-β-环糊精以摩尔比为1:2反应合成一种新型的联苯甲酰桥联β-环糊精(BBβ-CD)材料,并采用紫外可见分光光度法对其合成机理以及BBβ-CD和联苯甲酰对U(Ⅵ)的吸附行为进行研究;同时采用扫描电镜对材料吸附U(Ⅵ)前后的外貌形态进行表征。通过间歇吸附法考察p H、反应时间、温度以及干扰离子等因素对吸附过程的影响。结果表明,相比联苯甲酰,BBβ-CD能更有效地吸附U(Ⅵ),在p H=4.5,反应时间为60 min条件下,最大吸附量为12.16 mg?g^(-1),吸附率高达91.2%。动力学和热力学拟合结果表明,吸附过程更符合准二级动力学速率方程,Langmuir等温吸附模型比Freundlich等温吸附模型更适合模拟吸附过程,且吸附是自发吸热的过程。Sulfated β-cyclodextrin （β-CD） was prepared by the reaction of β-CD with p-toluenesulfonyl chloride at low temperature in aqueous sodium hydroxide. The product was analyzed by Fourier transform infrared spectroscopy （FTIR） and proton nuclear magnetic resonance （^1H NMR）. The novel benzil-bridged β-CD （BBβ-CD） was acquired by the reaction of benzil with sulfated β-CD at a molar ratio of 1 ： 2. UV spectrophotometry was used to study the synthetic mechanism of BBβ-CD and benzil and their adsorption onto U（VI）. Scanning electron microscopy （SEM） was used to analyze the surface properties of the materials. The adsorption of BBβ-CD onto U（VI） was investigated as a function of pH, contact time, temperature, and interfering ions using the batch adsorption technique. It was found that the adsorption equilibrium of BBβ-CD was reached faster than that of benzil. The optimum experimental conditions were pH = 4.5 and shaking for 60 rain, achieving the maximum adsorption capacity of 12.16 mg·g^-1 and a U（VI） removal ratio of 91.2%. Kinetic studies revealed that the adsorption reached equilibrium within 60 min for U（VI） and followed a pseudo-second-order rate equation. The isothermal data correlated with the Langmuir model better than with the Freundlich model. The thermodynamic data indicated the spontaneous and endothermic nature of the process.

关 键 词：联苯甲酰桥联β-环糊精 铀(VI)吸附 动力学 平衡 热力学 

分 类 号：O647.31[理学—物理化学]