Preparation and characterization of magnetic nanoparticles immobilized in acrylamide based hydrogels for metal extraction

Abstract

In recent years, smart hydrogel has attracted great attention especially in biomedical and pharmaceutical fields. Hydrogel has polymeric chain structure with a three-dimensional network that is able to swell significantly in aqueous environments. This study involves the development of magnetic hydrogel with nanoparticles for absorption of toxic metal ions (Cu (II), Ni (II), and Co (II)). The nanoparticles with magnetic properties were synthesized in poly acrylamide based hydrogels (method A-C). An in situ preparation process was employed to synthesize the nanoparticles with magnetic properties in hydrogel structure. The differences in rate of absorption between native and magnetic hydrogel was investigated in this study. Compared with native ones, apparently magnetic hydrogels can absorb higher amount of toxic metal ions due to the presence of magnetic nano particles. On the other hand, magnetic nanoparticles also provide large surface area which make them capable of absorbing more toxic metal ions. The highest percentage of absorbtion is attributed to AAm-co-AAc (0.6 gr) while the lowest one is for AAm-co-PEG (0.2 gr) (494 % and 23 % respectively). In absorption of toxic metal ions, AAm-co-AAc (0.6 gr) shows the best performance comparing to other types of hydrogels. This investigation shows that hydrogels and magnetic nano particles are applicable in waste water treatment and metal extraction application. The formation of magnetic nanoparticles in the polymer networks was determined by X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy and observed using Field Emission Scanning Electron Microscope (FESEM).