Effect of modified γ-Fe₂O₃ magnetic nanoparticles on the stability of heavy oil-in-water emulsions

Abstract

The effects of modified γ-Fe₂O₃ magnetic nanoparticles having various sizes at different mass fractions on the stability of heavy oil-in-water emulsions were compared. The zeta potential, wettability, oil-water interfacial tension, apparent viscosity, and oil droplet distribution of the emulsions were measured. The optimal size of the γ-Fe₂O₃(-COOH) magnetic nanoparticles was 2–3 μm, and this resulted in the lowest water-separation rate (23.72% at 4 hours), greatest electrostatic repulsion, weakest hydrophilic effect, lowest interfacial tension, greatest migration resistance, and smallest and most uniform oil droplet distribution. In addition, the stability of the emulsions increased and then decreased as the mass fraction of γ-Fe₂O₃ (-COOH) magnetic nanoparticles increased because of the increased electrostatic repulsion and decreased migration resistance. This in-depth analysis of the effect of modified magnetic nanoparticle size on the stability of oil-in-water emulsions provides comprehensive theoretical support for achieving viscosity and resistance reduction in an environmentally friendly manner.

GRAPHICAL ABSTRACT

Keywords:

• Modified magnetic nanoparticles
• stability
• oil droplet distribution
• zeta potential
• interfacial tension

Disclosure statement

All authors disclosed no relevant relationships.

Additional information

Funding

This project was supported by the National Natural Science Foundation of China (Approval No. 51904246), and the Xi’an Youth Science and Technology Lifting Project (095920221360).