Influence of concentration of FeCl3 solution on properties of polypyrrole-Fe3O4 composites prepared by common ion absorption effect

Polypyrrole (PPy)-Fe3O4 composites had been obtained by the use of common ion absorption effect. In our experiment, FeCl3 aqueous solution was used to disperse Fe3O4 nanoparticles to prevent the aggregation of Fe3O4 particles in solution. Due to common ion absorption effect, Fe3+ ions were absorbed onto the surface of Fe3O4 nanoparticles to form a positively charged (Fe3+) shell. This shell cannot only prevent the aggregation of Fe3O4 particles, but also initiate pyrrole monomer polymerization on the surface of Fe3O4 particles. In this paper, the influence of FeCl3 concentration on properties of PPy-Fe3O4 composites was discussed. PPy-Fe3O4 composites were characterized by transmission electron microscopy (TEM), atom absorption spectrophotometer, zetasizer, etc. The changes of zeta potential values and the average size of Fe3O4 particles showed that the dispersion of Fe3O4 particles was improved greatly, after being dispersed with FeCl3 solution. In all systems, the dosage of Fe3O4 particles and pyrrole monomer were the same, but the Fe content, conductivity and the saturated magnetization of PPy-Fe3O4 Composites all changed with the change of FeCl3 concentration, which was used to disperse Fe3O4 particles. The phenomenon may be caused by the rivalship of absorption and neutralization action of FeCl3 solution on Fe3O4 particles. (C) 2004 Elsevier B.V. All rights reserved.