Enhanced oil recovery(EOR)operations increasingly depend on emulsion-based formulations that exhibit long-term stability under reservoir conditions while minimizing surfactant dosage.In this context,hybrid systems com...Enhanced oil recovery(EOR)operations increasingly depend on emulsion-based formulations that exhibit long-term stability under reservoir conditions while minimizing surfactant dosage.In this context,hybrid systems combining nanoparticles and surfactants offer a promising route to achieving both interfacial stability and formulation efficiency.Among potential nanoparticle candidates,Ti_(3)C_(2)T_(x)MXene exhibits high surface area and interfacial activity.However,its application in diesel-in-water Pickering emulsions under EOR-relevant conditions has not been explored.Challenges such as high hydrophilicity and strong electrostatic repulsion have limited the use of unmodified MXene as a standalone stabilizer in colloidal systems.To address this limitation,diesel-in-water Pickering emulsions were formulated using DL-Ti_(3)C_(2)T_(x)MXene combined with Tween 40(0.5 wt%)and antifoam(0.15 wt%),aiming to investigate their synergistic stabilization behavior across MXene concentrations ranging from 0.1 to 1.5 wt%.The MXene-only system exhibited complete and immediate phase separation,whereas the hybrid emulsions demonstrated markedly enhanced stability,with no phase separation observed at 0.1 and 0.5 wt%after 24 h.A concentration-dependent trend was evident.At lower MXene contents,interfacial adsorption improved,and droplet sizes remained small and uniform.At higher concentrations(≥1.0 wt%),aggregation increased,and demulsification became more pronounced.Interfacial tension decreased steadily with increasing MXene content,reaching 0.86 mN/m at1.5 wt%,while zeta potential remained strongly negative(-47.7 mV at 0.5 wt%),indicating sufficient electrostatic repulsion.Rheological analysis revealed a transition to shear-thinning behavior at higher MXene contents,confirming the formation of internal network structures.Compared to other reported systems based on silica(SiO2),zinc oxide(ZnO),or functionalized MXenes,the MXene-Tween 40formulation achieved superior short-and long-term emulsion stability without requiring surface modification or external stimuli.To the best of our knowledge,this is the first study to report the successful stabilization of diesel-in-water Pickering emulsions using unmodified Ti_(3)C_(2)T_(x)MXene.These findings highlight the synergistic interaction between MXene and Tween 40 and present a robust,surfactant-lean formulation suitable for oilfield applications.展开更多
基金support of the Qatar National Research Fund(QNRF),grant reference number GSRA9-L-2-0511-22005。
文摘Enhanced oil recovery(EOR)operations increasingly depend on emulsion-based formulations that exhibit long-term stability under reservoir conditions while minimizing surfactant dosage.In this context,hybrid systems combining nanoparticles and surfactants offer a promising route to achieving both interfacial stability and formulation efficiency.Among potential nanoparticle candidates,Ti_(3)C_(2)T_(x)MXene exhibits high surface area and interfacial activity.However,its application in diesel-in-water Pickering emulsions under EOR-relevant conditions has not been explored.Challenges such as high hydrophilicity and strong electrostatic repulsion have limited the use of unmodified MXene as a standalone stabilizer in colloidal systems.To address this limitation,diesel-in-water Pickering emulsions were formulated using DL-Ti_(3)C_(2)T_(x)MXene combined with Tween 40(0.5 wt%)and antifoam(0.15 wt%),aiming to investigate their synergistic stabilization behavior across MXene concentrations ranging from 0.1 to 1.5 wt%.The MXene-only system exhibited complete and immediate phase separation,whereas the hybrid emulsions demonstrated markedly enhanced stability,with no phase separation observed at 0.1 and 0.5 wt%after 24 h.A concentration-dependent trend was evident.At lower MXene contents,interfacial adsorption improved,and droplet sizes remained small and uniform.At higher concentrations(≥1.0 wt%),aggregation increased,and demulsification became more pronounced.Interfacial tension decreased steadily with increasing MXene content,reaching 0.86 mN/m at1.5 wt%,while zeta potential remained strongly negative(-47.7 mV at 0.5 wt%),indicating sufficient electrostatic repulsion.Rheological analysis revealed a transition to shear-thinning behavior at higher MXene contents,confirming the formation of internal network structures.Compared to other reported systems based on silica(SiO2),zinc oxide(ZnO),or functionalized MXenes,the MXene-Tween 40formulation achieved superior short-and long-term emulsion stability without requiring surface modification or external stimuli.To the best of our knowledge,this is the first study to report the successful stabilization of diesel-in-water Pickering emulsions using unmodified Ti_(3)C_(2)T_(x)MXene.These findings highlight the synergistic interaction between MXene and Tween 40 and present a robust,surfactant-lean formulation suitable for oilfield applications.
