Investigation of Adsorption Capacity of Magnetite Nanoparticles

Abstract

In this work, the preparation of Fe3O4 nanoparticles modified with 3-aminopropyltriethoxysilane (APTES) was carried out under various synthesis modes (in air or in argon). The zeta potential and hydrodynamic diameter of Fe3O4-APTES nanoparticles were determined by the method of dynamic and electrokinetic light scattering. The effect of humic acids on the zeta potential, hydrodynamic diameter and colloidal stability of Fe3O4-APTES at different pH values was established by the method of dynamic and electrophoretic light scattering. It has been shown that changes in the conditions of the synthesis of nanoparticles of one component composition Fe3O4-APTES (argon) and Fe3O4-APTES (air) (in an inert medium and in an air atmosphere, respectively) lead to a change in the charge of the particle surface and a subsequent change in the sorption properties with respect to HA. It was demonstrated that the decisive role in the study of surface properties is played by the purification from low-molecular-weight impurities that can screen the surface of nanoparticles or bind with an indifferent electrolyte. The stage of dispersive post-preparation of samples is also important for the correct determination of the sorption capacity and hydrodynamic diameter of particles.