摘要
采用等离子体诱导方法在多壁碳纳米管(multi-walled carbon nanotubes,MWCNTs)上修饰上乙烯吡啶,获得乙烯吡啶改性碳纳米管(碳纳米管-乙烯吡啶,MWCNTs-g-VP)。用静态批实验的方法研究了pH值、吸附剂浓度和离子强度等因素对碳纳米管-乙烯吡啶富集放射性核素60 Co(Ⅱ)的影响。结果表明:引入乙烯吡啶不仅能改善碳纳米管在水溶液中的分散性,同时还能提高碳纳米管表面官能团的含量,进而提高碳纳米管对60 Co(Ⅱ)的富集效果;pH值与离子强度对碳纳米管-乙烯吡啶富集60 Co(Ⅱ)有显著影响;碳纳米管-乙烯吡啶富集60 Co(Ⅱ)的作用方式包括内层络合和外层络合。Langmuir模型拟合结果显示:在pH=7.5时,碳纳米管-乙烯吡啶对60 Co(Ⅱ)的最大富集量是13.9mg/g,相对较高的富集量说明碳纳米管-乙烯吡啶可以用于水溶液中放射性核素的富集。
Multi-walled carbon nanotubes（MWCNTs） were modified with 2-vinylpyridine （VP） by using Nz plasma technique. The application of MWCNTs-g-VP in the preconcentra- tion of 60Co（ Ⅱ ） from large volumes of wastewater was investigated under ambient condi tions. The results indicate that the VP molecules grafted on the surfaces of MWCNTs-g-VP can prevent the entanglement of MWCNTs and provide more functional groups, promoting the sorption of 60Co （ Ⅱ） on MWCNTs-g-VP. The preconcentration of 60Co （Ⅱ ） on MWCNTs-g-VP is strongly dependent on pH values and ionic strength, suggesting that inner-sphere complexation and outer-sphere complexation are the preconcentration mecha- nisms. According to the results simulated by Langmuir model, the maximum sorption caDac-ities （Cmax） of 60Co（ Ⅱ ） are 13. 9 mg/g on MWCNTs-g-VP at pH=7.5. The relatively high sorption capacity shows that MWCNTs-g-VP is a suitable material for the preconcentration and immobilization of radionuclides from large volumes of aqueous solutions in environmental pollution treatment.
出处
《核化学与放射化学》
CAS
CSCD
北大核心
2012年第6期331-336,共6页
Journal of Nuclear and Radiochemistry
基金
国家自然科学基金资助项目(No.20907055
21107115
21007074)
