Adsorption of sodium oleate from aqueous solutions on the surface of magnetite

The adsorption of sodium oleate from aqueous solutions on the surface of ma gnetite at 25 degreesC was studied by the adsorption equilibrium method and IR spectroscopy. Magnetite was synthesized by chemical condensation at var ious temperatures (5, 25, and 75 degreesC) under the action of a magnetic f ield (0, 0.5, and 1.0 T). To describe the adsorption isotherms, the Dubinin -Radushkevich-Astakhov equation was used. Based on this equation, the limit ing adsorption value, the characteristic energy of adsorption, and the volu me of the pores were calculated. The parameters of the adsorption isotherms were shown to depend on the conditions of adsorbent synthesis, such as the induction the magnetic field in the course of crystallization of particles and temperature. The IR spectra obtained showed that, as a result of the a dsorption of sodium oleate on the magnetite surface, pre-adsorbed water was displaced from the surface, and chemisorbed complexes of sodium oleate wit h the surface were formed.