synthesis and Identification of superparamagnetic graphene oxide- Iron oxide nanoparticles coated by chitosan and modified by Amino acid

Nanoparticles are promising materials with a variety of applications, whose surface modification is an important technique for developing these applications. In this study, a new nanostructure was synthesized in four steps that can be used to remove pollutants from wastewater. Firstly, the graphene oxide nanoparticles (GO) were synthesized by the modified Hummer method, and then by simultaneous precipitation of ferrous and ferric ions in based atmosphere on the surface of GO, graphene oxide was magnetized. Subsequently, magnetic nanoparticles of graphene oxide (m-GO) coated by chitosan saccharide polymer with covalent bonding. The magnetic graphene oxide nanoparticles coated with chitosan (m-GO@Chi) were bonded to the cysteine-glutaraldehyde schiff’s base (CG) with cross-linking method and their surface modified with cysteine (m-GO@Chi-Cys). After that, the nanoparticle surface correction process was investigated by using og identification analyzes. The results of the FT-IR spectroscopy indicated that surface modification was successful at each stage and the presence of epoxide, carbonyl, amino, and thiol functional groups at the nanoparticles level was confirmed. According to FESEM images, GO particles were synthesized in two dimensional and average thicknesses of 29-165nm and after magnetization, iron oxide nanoparticles with a mean size of 35-50nm were observed at the GO level. VSM analysis was used to study the magnetic properties of nanoparticles. The absence of residues in the nanosize magneticization curve and the negligible reduction in the saturation magnetization of m-GO@Chi-Cys nanoparticles, as compared to m-GO, is due to the presence of thin layer of chitosan on the primary particles.