The effect of surfactants on growth and form of monodispersed iron oxide particles

摘要

The effects of added surfactants on the size and shape of the monodispersed iron oxide particles prepared by forced hydrolysis from aqueous ferric chloride solutions were investigated by transmission electron microscopes. When the concentration of ferric chloride solutions increased, either the particle growth displayed clear delays or only a reaction intermediate of β-FeOOH was made. The cation and the amphoteric surfactant formed a spherical α-Fe_2O_3 within 12 hours regardless of the added concentration, and the anion delayed the growth of its particles or simply made the β-FeOOH as the concentration increased.