Published October 2026, Pg. 28-34
Section: Technique and technology of oil-gas production
UOT: 62-4+665.6/7
DOI: 10.37474/0365-8554/2026-10-28-34
New conceptual approaches to the mechanism of action of Janus nanoparticles for enhanced oil recovery
M.M. Asadov Dr. in Ch. Sc. - “Geotechnological Problems of oil, gas, and Chemistryˮ SRI, Institute of ChemistryThe development of advanced nanomaterials for enhanced oil recovery (EOR) requires not only improved efficiency but also a clear mechanistic understanding of particle–fluid–rock interactions at multiple length scales. In this work, a comprehensive and conceptually driven study of Janus nanoparticles is presented, focusing on the integration of controlled synthesis, interfacial catalysis, and mechanistic interpretation of their action in multiphase oil–water systems. Unlike conventional nanoparticles and surfactants, Janus nanoparticles possess an intrinsic asymmetry that enables directional interactions with immiscible phases and porous media, providing a fundamentally different mode of action.
A multistage synthetic strategy was developed to fabricate Janus colloidosomes with well-defined hydrophilic and hydrophobic domains. The approach combines emulsion-based size control, selective polymerization, and phase-specific surface functionalization. Catalytically active components, including gold nanoparticles and heteropolyanions (PW₁₂O₄₀³⁻), were immobilized exclusively on the hydrophilic side of the particles, while the hydrophobic side was modified with nonpolar functional groups to control wettability. Structural and compositional asymmetry was confirmed by scanning and transmission electron microscopy, elemental analysis, MAS NMR spectroscopy, and laser diffraction measurements, demonstrating the formation of monodisperse Janus nanoparticles with sizes in the range of 200–500 nm.
The interfacial behavior and dynamics of Janus nanoparticles were investigated experimentally and supported by GPU-based molecular simulations and density functional theory (DFT) calculations. The modeling results revealed stable self-orienting configurations of Janus particles at the oil–water interface, driven by asymmetric surface energies and localized intermolecular interactions. These findings provide a molecular-level explanation for the enhanced interfacial activity and stability of Pickering emulsions formed in the presence of Janus nanoparticles.
Based on the obtained results, several original conceptual mechanisms governing the action of Janus nanoparticles in porous media are proposed. The asymmetric wettability mechanism describes the ability of Janus particles to locally rearrange surface energies at the oil–water–rock interface, facilitating selective adsorption and oil displacement. The self-orienting behavior mechanism explains the directional alignment of particles under pressure, flow, and compositional gradients, which improves capillary control and emulsion stability. In addition, a dynamic interfacial activity mechanism is introduced, highlighting the adaptive response of Janus nanoparticles to changes in salinity, temperature, and shear conditions commonly encountered in reservoir environments.
A key conceptual contribution of this work is the “nano-anchor” micromechanism. According to this concept, Janus nanoparticles temporarily anchor at oil–rock interfaces due to their asymmetric surface chemistry, reducing water channeling and recirculation while increasing microscopic sweep efficiency. This mechanism provides a new perspective on how nanoparticles can actively participate in flow redistribution within porous media rather than acting solely as passive stabilizers.
Comparative studies demonstrate that Janus nanoparticles significantly outperform conventional nanoparticles and surfactants in biphasic catalytic and oil displacement systems. Phase-transfer reaction conversions increased from approximately 68 % for conventional systems to up to 97 % in the presence of Janus nanoparticles. At the same time, emulsion stability and residual oil recovery were substantially enhanced, confirming the synergistic effect of structural asymmetry, localized catalysis, and interfacial dynamics.
Overall, this work establishes a unified conceptual framework linking the synthesis, structure, and mechanism of action of Janus nanoparticles in enhanced oil recovery. The proposed mechanisms extend beyond traditional surfactant-based models and provide a universal platform for the rational design of smart interfacial nanomaterials applicable not only to EOR but also to a wide range of multiphase catalytic and separation processes.
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