Synthesizing dendritic mesoporous silica nanoparticles to stabilize Pickering emulsions at high salinity and temperature reservoirs

Nanoparticle-stabilized Pickering emulsions have significant application potential in various fields, including enhanced oil recovery. The close relationship between the nanoparticle morphology, size, surface roughness, and interfacial activity is a crucial factor for emulsion stability. In this study, dendritic mesoporous silica nanoparticles (DMSNs) with special mesoporous structure were successfully synthesized, and their ability to stabilize Pickering emulsions for enhanced oil recovery was investigated. Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction were used to confirm the successful fabrication of DMSNs. In addition, the effects and regulation mechanisms of the reaction time and TEOS addition on the morphology and pore structure of mesoporous nanomaterials were studied, the impact of the synthesis conditions with the results of the structural characterization was linked, the competitive nucleation and growth mechanisms of the dendritic mesoporous nanomaterials were further proposed. The stability of Pickering emulsions under high -temperature and high -salinity conditions was systematically evaluated at different scales by a variety of techniques, such as laser particle size analysis, optical microscopy, and static multiple light scattering. The results showed that the DMSNs-stabilized Pickering emulsions had good stability even at high -mineralization -degree (30,000 mg/L) and high -temperature (80 degrees C) reservoirs. N2 physical adsorption-desorption curves and emulsion stability studies suggested that DMSNs with higher specific surface areas and surface roughness values exhibited enhanced surfactant -loading capacities and binding affinities. These properties enable the formation of a mechanical barrier at the oil-water interface and increase the interfacial strength, which are essential for the long-term stability of emulsions. Moreover, the results of core flooding experiments indicated that the DMSNs-stabilized emulsions could significantly enhance oil recovery (by 27.6%). Finally, based on microscopic visualization experiments, a potential enhanced oil recovery mechanism was proposed. These novel findings in this work could extend the knowledge about DMSNs-stabilized Pickering emulsion in EOR.