Molecular dynamics study on iron oxide nanoparticles stabilised with Sebacic Acid and 1,10-Decanediol surfactants

Abstract

By using molecular dynamics in canonical ensemble (constant atom number, volume and temperature (NVT)) the adsorption of Sebacic Acid (SA) and 1,10-Decanediol (DD) respectively onto the surfaces of an iron-oxide nanoparticle is simulated. The nanoparticle is built by taking into account the inverse spinel structure of a stoichiometric magnetite and the valence of the iron ions (FeA2+FeB2+FeB2+ where A and B stand for tetrahedral and octahedral sites, respectively). This study serves to determine theoretically whether surfactants like SA or DD acts as a better stabilising agent for iron oxide nanoparticles of diameters ⩾2.6nm. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) measurements on iron oxide nanoparticles stabilised with SA- and DD surfactants were obtained and compared to the simulated results. Unagglomerated nanoparticles with well-defined edges were observed during TEM for DD stabilised particles and a smaller particle size could be calculated for these nanoparticles from XRD patterns. It is concluded that DD stabilises an iron-oxide nanoparticle better than SA because of the difference in the number of oxygen atoms on the respective functional groups.