State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing 210009, PR China.
State Key Laboratory of Materials-Oriented Chemical Engineering and College of Chemistry and Chemical Engineering, Nanjing Tech University, Nanjing 210009, PR China.
J Hazard Mater. 2015 Jul 15;292:90-7. doi: 10.1016/j.jhazmat.2015.03.014. Epub 2015 Mar 9.
We report here the preparation of porous magnetic polyacrylamide microspheres for efficient removal of cationic dyes by a simple polymerization-induced phase separation method. Characterizations by various techniques indicate that the microspheres show porous structures and magnetic properties. They can adsorb methylene blue with high efficiency, with adsorption capacity increasing from 263 to 1977 mg/g as the initial concentration increases from 5 to 300 mg/L. Complete removal of methylene blue can be obtained even at very low concentrations. The equilibrium data is well described by the Langmuir isotherm models, exhibiting a maximum adsorption capacity of 1990 mg/g. The adsorption capacity increases with increasing initial pH and reaches a maximum at pH 8, revealing an electrostatic interaction between the microspheres and the methylene blue molecules. The microspheres also show high adsorption capacities for neutral red and gentian violet of 1937 and 1850 mg/g, respectively, as well as high efficiency in adsorption of mixed-dye solutions. The dye-adsorbed magnetic polyacrylamide microspheres can be easily desorbed, and can be repeatedly used for at least 6 cycles without losing the adsorption capacity. The adsorption capacity and efficiency of the microspheres are much higher than those of reported adsorbents, which exhibits potential practical application in removing cationic dyes.
我们在此报告了一种通过简单的聚合诱导相分离方法制备用于有效去除阳离子染料的多孔磁性聚丙烯酰胺微球的方法。各种技术的表征表明，微球具有多孔结构和磁性。它们可以高效地吸附亚甲蓝，随着初始浓度从 5mg/L 增加到 300mg/L，吸附容量从 263mg/g 增加到 1977mg/g。即使在非常低的浓度下也可以完全去除亚甲蓝。平衡数据很好地符合 Langmuir 等温线模型，表现出最大吸附容量为 1990mg/g。吸附容量随初始 pH 值的增加而增加，在 pH 值为 8 时达到最大值，这表明微球与亚甲蓝分子之间存在静电相互作用。微球对中性红和龙胆紫的吸附容量分别为 1937mg/g 和 1850mg/g，对混合染料溶液的吸附效率也很高。吸附了染料的磁性聚丙烯酰胺微球可以很容易地解吸，并可以至少重复使用 6 次而不会失去吸附容量。微球的吸附容量和效率都远远高于已报道的吸附剂，这在去除阳离子染料方面显示出潜在的实际应用。
