| 改性水凝胶的制备及其对Pb2+、Cd2+吸附性能研究 |
| 摘要点击 4535 全文点击 1884 投稿时间：2012-09-22 修订日期：2012-12-24 |
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| 中文关键词 低温辐射 共聚物水凝胶 胺化改性 重金属离子 吸附机制 |
| 英文关键词 low-temperature radiation copolymer hydrogel amination modification heavy metal ions adsorption mechanism |
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| 中文摘要 |
| 采用60 Co-γ射线低温辐射技术,以丙烯酸羟乙酯(HEA)和N-乙烯基甲酰胺(NVF)为共聚单体,合成了一种新型共聚物水凝胶:聚(丙烯酸羟乙酯/N-乙烯基甲酰胺)[p(HEA/NVF)],并采用三乙烯四胺(TETA)对其进行胺化改性,制得一改性水凝胶:聚(丙烯酸羟乙酯/N-乙烯基甲酰胺)-三乙烯四胺[p(H/V)-T]. 对制备的p(HEA/NVF)凝胶进行了SEM分析和FTIR分析,并对改性后的p(H/V)-T进行XPS分析及FTIR分析. 研究了改性前后水凝胶对重金属Pb2+、Cd2+的吸附性能,改性后水凝胶对Pb2+、Cd2+的吸附动力学,以及重金属离子初始浓度、pH值等对改性凝胶吸附性能的影响,并对吸附重金属前后的水凝胶进行电子能谱分析. SEM分析表明,p(HEA/NVF)水凝胶是一种具有多孔结构的高分子材料; 吸附实验结果表明,相比较p(HEA/NVF),p(H/V)-T对Pb2+的吸附量增加了700%,对Cd2+的吸附量增加了600%; p(H/V)-T对Pb2+、Cd2+的吸附量随着pH的升高而增加,吸附过程满足准二级动力学方程,并均能较好地符合Freundlich和Langmuir等温吸附模型(R2>0.95); 红外分析证实,HEA和NVF已成功聚合为一新型共聚物水凝胶,且多胺基团已被成功地接于共聚物水凝胶表面; XPS分析得出,改性后水凝胶p(H/V)-T对重金属Pb2+、Cd2+的吸附机制为两者之间的螯合作用. |
| 英文摘要 |
| A novel copolymer hydrogel poly(Hydroxyethyl methacrylate/N-Vinylformamide) [p(HEA/NVF)] was prepared by 60 Co-γ induced copolymerization, using low-temperature radiation technique. Triethylenetetramine(TETA) was applied to modify the prepared hydrogel into an ammoniated hydrogel poly(Hydroxyethyl methacrylate/N-Vinylformamide)-TETA [p(H/V)-T]. The two hydrogels prepared were characterized by using FTIR spectrometry and the p(HEA/NVF) was scanned by SEM. Moreover, the p(H/V)-T hydrogels were analyzed by XPS before and after adsorption. The adsorption capacities of Pb2+, Cd2+ on p(HEA/NVF) and p(H/V)-T were investigated. And the effects of pH, time and initial metal ion concentration on the adsorption of Pb2+, Cd2+ by p(H/V)-T were examined in batch experiments. SEM photos showed that p(HEA/NVF) hydrogel is a macroporous polymer material. Compared to the p(HEA/NVF) hydrogel, the adsorption capacities of Pb2+, Cd2+ on p(H/V)-T increased by 700% and 600%, respectively. The adsorption behaviors for Pb2+and Cd2+ confirmed that the adsorption on p(H/V)-T followed the pseudo-second-order rate equation and was fitted to both Langmuir and Freundlich adsorption model (R2>0.95). Besides, the adsorption capacities of p(H/V)-T increased with increasing pH values. The FTIR spectra verified that p(HEA/NVF) was indeed a copolymer of HEA and NVF monomers, and the multi-amine groups have been successfully grafted to the surface of the copolymer hydrogel. The XPS analysis concluded that the mechanism of Pb2+ and Cd2+ by p(HEA/MALA) could be the chelation between -NH2 and metal ions. |
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