吡啶基改性纤维状介孔二氧化硅微球的辐射制备及其对U(Ⅵ)的吸附性能  

Pyridine-modified fibrous mesoporous silica microspheres prepared through radiation-induced grafting polymerization and their adsorption property to U(Ⅵ)

作　　者：赵驰 翁汉钦 汪谟贞[1] 葛学武[1] 林铭章[2] ZHAO Chi WENG Hanqin WANG Mozhen GE Xuewu LIN Mingzhang(School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230027, China CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, China)

机构地区：[1]中国科学院软物质化学重点实验室中国科学技术大学化学与材料科学学院高分子科学与工程系,合肥230026 [2]中国科学技术大学核科学技术学院,合肥230027

出　　处：《辐射研究与辐射工艺学报》2017年第5期17-25,共9页Journal of Radiation Research and Radiation Processing

基　　金：安徽省自然科学基金(1708085QA21);中国博士后科学基金(2016M592069);中央高校基本科研业务费(WK2140000009)资助~~

摘　　要：首先合成了双键改性的纤维状介孔二氧化硅纳米微球(F-SiO_2-K),将其分散在4-乙烯基吡啶(4-vinylpyridine,4-VP)或4-VP的甲醇溶液中,通过共辐射接枝的方法,制备了吡啶基改性纤维状介孔SiO_2纳米微球(F-SiO_2-VP)。热重分析结果表明,聚4-乙烯基吡啶(P(4-VP))在F-SiO_2微球上的接枝率随4-VP单体浓度和吸收剂量增加而增加,但随剂量率的增加先增大后减小。将F-SiO_2-VP微球分散在含有U(Ⅵ)的硝酸溶液中,测定了室温下微球对U(Ⅵ)的吸附容量,并对吸附动力学和吸附等温线进行了分析。结果表明,F-SiO_2-VP微球对U(Ⅵ)的吸附容量与硝酸浓度和P(4-VP)的接枝率有关。当硝酸浓度为5 mol/L,P(4-VP)的接枝率为16%时,对U(Ⅵ)的吸附容量最大,达到163 mg/g。该吸附过程符合准二级动力学模型,其吸附热力学则当U(Ⅵ)浓度低时符合Freundlich模型,而U(Ⅵ)浓度高时符合Langmuir等温吸附模型。In this paper, double-bond-modified fibrous mesoporous silica（F-SiO2-K） microspheres were prepared first, and then grafted with poly（4-vinylpyridine）（P（4-VP）） in 4-VP or its methanol solution initiated by γ-ray irradiation to obtain pyridine modified mesoporous silica（F-SiO2-VP） microspheres. The Fourier transform infrared spectroscopy（FTIR） and thermal gravimetric analysis（TGA） results indicated the successful grafting of P（4-VP）. The degree of grafting（DG） of P（4-VP）, which was calculated from TGA curves, increased with the monomer concentration and the absorbed dose, however reached a maximum value at a moderate dose rate. The adsorption ability of F-SiO2-VP for U（Ⅵ） in nitric acid solution was investigated. The results show that the adsorption capacity is related to the concentration of nitric acid and the DG of F-SiO2-VP, and reaches a maximum of 163 mg/g. The adsorption kinetics fits the pseudo-second-order model, and the adsorption isotherm of F-SiO2-VP fits the Freundlich model at low U（Ⅵ） concentrations and the Langmuir isotherm well at high U（Ⅵ） concentrations.

关 键 词：Γ射线 辐射接枝 介孔二氧化硅 4-乙烯基吡啶 U(Ⅵ) 

分 类 号：TL13[核科学技术—核能科学]