聚乙烯亚胺-膨润土复合材料对橙黄Ⅱ的吸附性能研究

摘要

To improve the adsorption properties of bentonite for anionic dyes, the polyethyleneimine-bentonite composites were prepared taking polyethyleneimine as a modifier and protonating amino groups on polytene by epichlorohydrin.The technical means of IR, zeta potential, TGA, SEM, and XRD were used to characterize the samples.The experiments on adsorbing of OrangeⅡin water were carried out taking the prepared modified bentonite as an adsorbent.The results indicate that polyethyleneimine is successfully grafted onto the surface of bentonite and the surface contains a large amount of amino, which is attributed to the protonation of surface amino groups by epichlorohydrin.The modified bentonite can be regarded as an adsorbent to remove OrangeⅡ from aqueous solution.The adsorption performance of modified bentonite for OrangeⅡ is not influenced by pH value and the adsorption equilibrium time was 2h.The maximum adsorption capacity of modified bentonite is 1274mg/g at 318K, which has outstanding adsorption property.The adsorption kinetics study of OrangeⅡ onto polyethyleneimine-bentonite composites obeys the pseudo-second-order model, and the adsorption isotherm data are fitted well to Langmuir isotherm.%为了提高膨润土对阴离子染料的吸附性能,以聚乙烯亚胺为改性剂,利用环氧氯丙烷使聚乙烯上氨基质子化,制得聚乙烯亚胺-膨润土复合材料,并利用红外光谱、zeta电位、热重分析、扫描电子显微镜、X射线衍射等技术手段进行表征;将制备的改性膨润土作为吸附剂,进行去除水中橙黄Ⅱ的吸附研究.结果表明:聚乙烯亚胺成功接枝到膨润土且使其表面含有大量的氨基,环氧氯丙烷使表面氨基质子化,使得改性膨润土可以作为吸附剂用于吸附水中的橙黄Ⅱ;改性后的膨润土对橙黄Ⅱ的吸附性能不受pH的影响,吸附平衡时间为2h,改性膨润土在温度为318K下最大吸附量为1274mg/g,吸附性能优异;吸附过程遵循准二级动力学模型,且符合Langmuir吸附等温线.