Molecular dynamics simulation of binary betaine and anionic surfactant mixtures at decane - Water interface

Cai, Haibing; Zhang, Yi; Liu, Ziyu; Li, Jianguo; Gong, Qi; Liao, Qi; Zhang, Lu; Zhao, Suoqi

doi:10.1016/j.molliq.2018.06.047

Cited by 42 publications

(16 citation statements)

References 40 publications

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“…Molecular dynamics (MD) simulations are particularly well suited for this purpose and have been applied to oil/water/surfactant systems since the late 1980s − and later on with fully atomistic, optimized, and experimentally validated molecular models (“force fields”). − However, these studies were primarily focused on other aspects like surfactant dynamics, micelle morphologies, or droplet coalescence …”

Section: Introductionmentioning

confidence: 99%

Ionic Surfactants at Air/Water and Oil/Water Interfaces: A Comparison Based on Molecular Dynamics Simulations

et al. 2021

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Ionic surfactants are known to build up higher interfacial pressures at oil/water interfaces than at air/water interfaces for the same surfactant bulk concentration. Here, we systematically investigate this effect through atomistic molecular dynamics (MD) simulations of surfactant-loaded air/water and oil/water interfaces. Two prototypical ionic surfactants, C12TAB and sodium dodecyl sulfate (SDS), are studied and found to give consistent results, which are also robust with respect to variations in the simulation force field. The simulations reproduce the experimental interfacial pressure data on a semiquantitative level and reveal that the influence of oil on the surfactants’ in-plane distribution is a major contribution to the observed effect, albeit insufficient to be the sole reason. The simulations are further analyzed with regard to surfactant/oil cooperative/competitive effects that have been invoked recently as an explanation. However, the interfacial orientation of oil molecules, a presumable indicator for such behavior, is found to display changes only for high levels of surfactant coverage.

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Section: Introductionmentioning

confidence: 99%

Ionic Surfactants at Air/Water and Oil/Water Interfaces: A Comparison Based on Molecular Dynamics Simulations

et al. 2021

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“…Over time, the oil droplet almost does not changes. It can be concluded that, because of the existence of LHSB molecules, the wettability of quartz has changed and the oil droplet is easy to adhere to its surface …”

Section: Resultsmentioning

confidence: 99%

“…To analyze the wetting behavior of the oil drop on quartz decorated with surfactants, CGMD simulation was used in this study. In comparison to atomic simulation models, the coarse-grained (CG) models, − which map a group of atoms into one single site, allow simulations to be carried out on a larger length scale and longer time scale. All simulations were performed by GROMACS 4.6.7 with a Martini force field.…”

Section: Methodsmentioning

confidence: 99%

Mechanism of the Wettability Impact on Surfactant Imbibition in Dodecane-Saturated Tight Sandstone

et al. 2020

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As a result of low porosity and low permeability in tight reservoirs, spontaneous imbibition plays an important role in oil recovery. While wettability has a crucial impact on the imbibition, the mechanism of the effect of wettability on imbibition is still unclear. In this study, we screened the surfactants with similar interfacial tension (IFT) at the same concentration to study the wettability properties, which will contribute to improve the oil recovery tight reservoir. Two betaine surfactants, lauramide propyl hydroxysulfonated betaine (LHSB) and cocamidopropyl betaine (CAB), were screened according to their IFT. Through spontaneous imbibition experiments, the recovery of LHSB (27.26%) was better than that of CAB (21.69%). The contact angle method and U.S. Bureau of Mines method were used to analyze the core wettability comprehensively. After LHSB treatment, the core wettability index turned to hydrophobic and the wettability index changed from −0.06 to −0.56. However, the wettability index did not change significantly after CAB treatment (−0.15). Further molecular simulations showed that, after the surface of the rock is modified by LHSB, the oil droplets spread gradually and the interface energy with the quartz was enhanced. In combination of the analysis of the ζ potential and adsorption measurement, LHSB is predicted to be adsorbed in a single-layer configuration, while CAB formed a double-layer configuration, which caused the difference in wettability. It can be speculated that, when the surfactant changes the pore surface of the tight sample toward hydrophobic, the oil-wet surface promotes the residual oil droplets to form a continuous phase and, at the same time, reduces flow resistance of the water phase, thereby increasing the spontaneous imbibition rate and the ultimate recovery. This study will help to understand the wettability impact on imbibition by the surfactant and contribute to the improvement of tight oil reservoir recovery.

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“…They found that the polyethylene oxide chains could wrap around the surfactant micelles and decrease the solvent-accessible surface area of the surfactant in the micelles. In addition, many MD simulation investigations also focused on the interfacial behaviors in various surfactant systems. − Domínguez’s investigation revealed that the tails in an anionic surfactant were more disordered in the anionic/nonionic surfactant mixed adsorbed layer than in the single monolayer. The additional nonionic surfactant disturbed the original ordered distribution of the anionic surfactant in the interfacial adsorption layer .…”

Section: Introductionmentioning

confidence: 99%

Effects of Micellization Behavior on the Interfacial Adsorption in Binary Anionic/Nonionic Surfactant Systems: A Molecular Simulation Study

et al. 2021

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A surfactant interfacial adsorption process is highly associated with its micellization behaviors in the water phase, which is of great fundamental and practical significance in enhanced oil recovery. In this paper, the typical anionic surfactant 1-dodecanesulfonic acid sodium (DAS) and nonionic surfactants octylphenol polyoxyethylene ether-n (OP-n, n = 1, 5, and 10) are introduced to investigate their micellization behavior and interfacial adsorption process via molecular dynamics simulation. Number density profiles reveal that the additional OP5 molecules in the water phase generate the mixed micelle with DAS molecules and greatly promote its interfacial adsorption. Interaction energy calculation is employed to confirm the interaction of anionic/nonionic surfactants in the mixed micelle. Then, the radial distribution function, solvent-accessible surface area, and solvation free energy are calculated to further explore and verify the adsorption mechanism of the mixed micelle. It is found that the nonionic surfactant obviously decreases the hydrophilicity of the mixed micelle in the water phase, which should be responsible for its intensive tendency of the interfacial adsorption.

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Molecular dynamics simulation of binary betaine and anionic surfactant mixtures at decane - Water interface

Cited by 42 publications

References 40 publications

Ionic Surfactants at Air/Water and Oil/Water Interfaces: A Comparison Based on Molecular Dynamics Simulations

Ionic Surfactants at Air/Water and Oil/Water Interfaces: A Comparison Based on Molecular Dynamics Simulations

Mechanism of the Wettability Impact on Surfactant Imbibition in Dodecane-Saturated Tight Sandstone

Effects of Micellization Behavior on the Interfacial Adsorption in Binary Anionic/Nonionic Surfactant Systems: A Molecular Simulation Study

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