氨基功能化磁性Fe_3O_4纳米粒子去除Cu(Ⅱ)离子的研究

Removal of Cu(Ⅱ) ions by NH_2-functionalized magnetic Fe_3O_4 nanoparticles

以化学共沉淀法制备Fe3O4纳米颗粒,先通过碳二亚胺活化在其表面接枝聚丙烯酸,紧接着用乙二胺对其表面进行修饰,得到富含氨基官能团磁性纳米吸附剂(Fe3O4@PAA-EDA).通过红外光谱(FT-IR)、透射电镜(TEM)、X射线衍射(XRD)、振动样品磁强计(VSM)等对其进行了表征,着重研究了其对废水中Cu(Ⅱ)离子的吸附性能.结果表明,溶液的pH值能显著影响吸附剂对Cu(Ⅱ)离子的吸附效果,pH为5时效果最佳;结合相应pH值下的竞争反应,探讨了该吸附剂对Cu(II)离子的吸附机理.结果表明,吸附过程以螯合作用与静电引力为主;等温吸附数据符合Langmuir模型,T=298 K,pH=5,V=5 mL时,吸附剂的饱和吸附容量qm为11.88 mg/g,吸附常数为0.0183 L/mg.

A novel magnetic nanoabsorbent with abundant amino groups（Fe3O4@PAA-EDA） is prepared by covalent binding of polyacrylic acid（PAA） on the surface of Fe3O4 nanoparticles and then followed by amino-functionalization using ethanediamine（EDA） via carbodiimide activation.The absorbent is characterized by FT-IR,TEM,XRD,and VSM.Moreover,the absorption properties of the absorbent for Cu（Ⅱ） ions are also investigated.The results show that the absorption capability is significantly affected by pH,the optimum pH value is 5;With the competitive reaction under the corresponding pH conditions,the absorption mechanism of Cu（Ⅱ） ions including chelating and electrostatic gravitation are also discussed.The absorption data obey the Langmuir equation with a maximum absorption capacity of 11.88 mg/g and a Langmuir absorption equilibrium constant of 0.0183 L/mg.