Electrokinetic properties of magnetite particles and cobalt ferrite obtained in the Fe0(St3)-H2O-O2 system and stability of their aqueous suspensions
Year: 2025
Type: article
Abstract: Under optimal conditions, we synthesized magnetite particles in the systems Fe0(Ст3)-H2O-O2 including those containing iron(II) or iron(III) sulfates. The cobalt ferrite particles were obtained with the Fe0(St3)-H2O-O2 system in the presence of cobalt(II) chloride. The samples were characterized using XRD, SEM, microelectrophoresis, and nephelometry. The dependences of the electrokinetic potential of the obtained particles on the pH of the dispersion medium, in particular, in the presence of a non-indifferent electrolyte (cobalt(II) chloride), were obtained. For magnetite and cobalt ferrite particles, while changing the dispersion medium pH from acidic to alkaline levels, the sign of the electrokinetic potential changed from positive to negative values. The observed isoelectric point belongs to the pH range 7-7.5. In a non-indifferent electrolyte solution with the potential-determining Co2+- ions, the cobalt ferrite particles within the studied pH range, 5-10, had positive Zeta Potential values of ~15-23 mV. Thus, the recharging of particles was not observed. It was found that, due to the action of ionic-electrostatic and dispersion forces, the aqueous suspensions of the synthesized particles are stable concerning the aggregation–sedimentation. On the basis of the obtained results, the coagulation (contact-recrystallization) mechanism is assumed to be a possible mechanism of the magnetite particle formation in the Fe0(St3)-H2O-O2 system. The formation of cobalt ferrite particles occurs by coagulation and condensation-crystallization mechanisms depending on the conditions of precursor fluctuations on individual surface microsites where their formation occurs.
Source: Results in Chemistry
Authors: Vitalii Prokopenko, Svitlana Netreba, Olena Tsyganovych, Tetiana Borodinova, Andrii Panko
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,870
OpenAlex ID: W7116120751