Modification of CoFe2O4 Magnetic Nanoparticles by Dopamine and Ascorbic Acid as Anchors

CoFe2O4 magnetic nanoparticles were modified by dopamine (DA) and ascorbic acid (AA) as anchors.Separation of the DA and AA using CoFe2O4 magnetic nanoparticles have been studied by investigating the effects ofpH, concentration of the DA and AA, amount of adsorbents, contact time, ionic strength and temperature. The mechanismof adsorption was also studied. The adsorption of DA and AA to the CoFe2O4 magnetic nanoparticles could be describedby Langmuir-type adsorption isotherms. The maximum adsorption capacities were 28.98 and 72.99 mg of enediol pergram of adsorbent for DA and AA, respectively. With the help of adsorption isotherm, thermodynamic parameters suchas free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) have been calculated. The adsorption of DA onto CoFe2O4 isexothermic, but the temperature effect was negligible for adsorption of AA. Surface modification with enediol ligandshave been investigated using Fourier transform infrared spectroscopy (FTIR). On the basis of pseudo-first-order andpseudo-second-order kinetic equations different kinetic parameters have been obtained.

Keywords:

Magnetic nanoparticle , Dopamine , Ascorbic acid