Detemining Chromium Adsorption Isotherms on Magnetic Nanoparticles Functionalized Using Poly[Allylamine-( N,N-Dimethylacrylamide)]

The paper presents a new approach of using functionalized magnetite nanoparticles (MNPs) for chromiumadsorption. A functional chelating group is formed by Free-radical co-polymerization of N,Ndimethylacrylamideand allylamine, which is grafted onto MNPs using (3-mercaptopropyl)trimethoxysilaneas the novel adsorbent. The grafted MNPs were characterized by FTIR, elemental analysis,thermogravimetric analysis, transmission electron microscopy, and scanning electron microscopy. Theequilibrium sorption data for Cr(VI) onto the polymeric sorbent was analyzed using the Langmuir,Freundlich, and Redlich–Peterson models. In the Redlich-Peterson model, g equaled 0.98, indicating thatthe Langmuir isotherm is the best model.