Synthesis and lead ion absorption of magnetic hydrogel nanocomposite absorbents with semi-IPNs structure

γ-Methacryloxypropyl trimethoxysilane (KH570)-modified magnetic hydrogel nanocomposite absorbents with semi-interpenetrating networks (semi-IPNs-KH570-mHNAs) were synthesized by radical copolymerization via poly(acrylamide-co-acrylic acid), polyvinyl pyrrolidone (PVP) and KH570-modified magnetic nanoparticles. FTIR and XRD results preliminarily confirmed the target structure of semi-IPNs-KH570-mHNAs without destroying the structure of magnetic nanoparticles during KH570 modification and radical polymerization. Semi-IPNs-KH570-mHNAs with many porous and ravine structure had high adsorption capacity for Pb(II) (450 mg/g). Semi-IPNs-KH570-mHNAs had the best absorption capacity for Pb(II) ion in the synthesis condition of acrylic acid/acrylamide mass ratio of 60:40, 0.8% initiator, acrylic acid (AA) neutralization degree of 70%, 0.2% cross-linker, 12% PVP and 10% KH570-modified magnetic nanoparticles. Besides, semi-IPNs-KH570-mHNAs had good magnetic responsiveness, high thermal stability, reusability which made it a potential application in removing heavy metal ions from the contaminated wastewater.