Polyethylenimine(PEI)-modified magnetic hydrogel nanocomposite absorbents (PEI-mHNAs) were fabricated based on poly(acrylamide-co-acrylic acid) and PEI-modified magnetic nanoparticles by radical copolymerization. FTIR and XRD results preliminarily confirmed the target structure of PEI-mHNAs without destroying the structure of magnetic nanoparticles during modification and radical copolymerization. PEI-mHNAs with many rough porous and interstitial structure had high adsorption capacity of Cu(II) (217 mg/g), Cd(II) (232 mg/g) and Pb(II) (459 mg/g). PEI-mHNAs had the best absorption capacity for heavy metal ions in the synthesis condition of acrylic acid/acrylamide mass ratio of 60:40, 0.8% initiator, AA neutralization degree of 70%, 0.75% crosslinker, and 15% PEI-modified magnetic nanoparticles. Moreover, PEI-mHNAs had good magnetic responsiveness, high thermal stability and reusability, which make it a potential application in removing heavy metal ions from the contaminated wastewater.

聚乙烯亚胺（PEI）改性磁性水凝胶纳米复合吸收剂（PEI-mHNAs）是基于聚丙烯酰胺-共聚丙烯酸和PEI改性磁性纳米粒子通过自由基共聚制备的。FTIR和XRD结果初步证实了PEI-mHNAs的目标结构，在改性和自由基共聚过程中不破坏磁性纳米粒子的结构。具有许多粗糙多孔和间隙结构的 PEI-mHNA 对 Cu(II) (217 mg/g)、Cd(II) (232 mg/g) 和 Pb(II) (459 mg/g) 具有较高的吸附能力。PEI-mHNAs在丙烯酸/丙烯酰胺质量比60:40、0.8%引发剂、AA中和度70%、0.75%交联剂、15%PEI改性磁性的合成条件下对重金属离子的吸附能力最好。纳米粒子。此外，PEI-mHNAs 具有良好的磁响应性，